Dr. Stefan Gerhardt

Princeton Plasma Physics Laboratory

Princeton, NJ 08543

sgerhard@pppl.gov

Education:

· Ph.D.: Electrical Engineering, U. of Wisconsin-Madison, 2004.

· M.S.: Electrical Engineering, U. of Wisconsin-Madison, 2001.

· B.S.: Interdisciplinary Degree in Applied Math, Engineering and Physics, U. of Wisconsin-Madison, 1998.

Awards:

· Presidential Early Career Award in Science and Engineering (PECASE), 2009

· American Physical Society Marshall Rosenbluth Award for Outstanding Doctoral Dissertation in Plasma Physics, 2005.

· Harold Peterson Award: Outstanding Dissertation in the U. of Wisconsin Electrical Engineering Department, 2005.

· DOE/Oak Ridge Associated Universities Award to attend the 51^st Meeting of Nobel Laureates in Lindau, Germany, 2001.

· Albert Augustus Radtke Scholarship, UW-Madison Physics Department, 1998.

· Phi Beta Kappa, U. of Wisconsin-Madison, 1997.

· National Undergraduate Fellowship Program in Plasma Physics and Fusion Energy Sciences, 1996.

Work Experience:

· 2009-Present: Research Physicist, National Spherical Torus Experiment (NSTX)

· Spring 2007-2009: Staff Research Physicist, National Spherical Torus Experiment (NSTX)

· Fall 2006-Fall 2007: Staff Research Physicist, Magnetic Reconnection Experiment, Princeton Plasma Physics Laboratory (PPPL)

· Summer 2004-Fall 2006: Associate Research Physicist, Magnetic Reconnection Experiment, Princeton Plasma Physics Laboratory

· Summer 1998-Spring 2004: Graduate Student at Helically Symmetric eXperiment, Madison, U. of Wisconsin.

· Fall 1996-Spring 1998: Undergraduate Researcher, Madison Symmetric Torus, Madison, U. of Wisconsin.

· Summer 1996: Summer Student, Magnetic Reconnection Experiment, PPPL.

· Fall 1995-Spring 1996: Undergraduate Hourly, Madison Symmetric Torus, Madison, Wisconsin.

Key Scientific Contributions:

· Disruption halo currents: Developed innovative halo current diagnostics and measurements of halo current characteristics, including characterization of the critical non-axisymmetric dynamics of these currents [S.P. Gerhardt, et al, NF 53, 023005 (2013)].

· Disruption detection: Development of physics-based disruption detection algorithms that synthesizes the results of many real time measurements but does not rely on neutral-network training, achieving a high detection rate with minimal late warnings and false positives – important for FNSF/ITER/DEMO [S. P. Gerhardt, et al, NF 53, 063021 (2013)].

· Disruptivity studies in high-performance ST plasmas: Demonstrated that the NSTX disruptivity is minimized in high-b_N scenarios with strong boundary shaping and broad plasma profiles. [S.P. Gerhardt, et al, NF 53, 043020 (2013)].

· Plasma control development: Implemented b_N control using pulse-width modulated neutral beams as an actuator, and implemented numerous improvements to both RWM and vertical position control systems [S.P. Gerhardt, et al, Fusion Sci. Tech. 61, 11 (2012)].

· Predictive scenario modeling for NSTX-Upgrade: Used new free-boundary TRANSP to complete a comprehensive study of NSTX-U scenarios, including a range of 100% non-inductive scenarios, high-b_t cases, and very long pulse examples; these simulations now being used for both diagnostic simulations for NSTX-U and development of coil and power supply operations requirements [S.P. Gerhardt, et al, NF 52, 083020 (2012)].

· TAE avalanche induced current transport: Developed phenomenological model of fast ion current redistribution due to TAE avalanches, eliminating discrepancies in the current profile modeling that occurred without the redistribution – motivates studies of TAE for NBI-CD redistribution for FNSF and ITER-AT [S.P. Gerhardt, et al, NF 51, 033004 (2011)].

· Experimental development of high-performance ST scenarios: Lead high-b_t (2008) and high-f_NI (2009) discharge development, including the highest sustained elongation in NSTX, development of the low internal-inductance scenarios used for RWM control, and NSTX-U scenario prototyping [S.P. Gerhardt, et al, NF 51, 083047 (2011)].

· ST confinement scaling: Quantified the scaling (with P_inj, n_e, B_t, I_p) of confinement and non-inductive current components over a wide range of NSTX H-mode scenarios. Experimental results used to inform modeling assumptions for NSTX-Upgrade and next-step STs [S.P. Gerhardt, et al, NF 51, 083047 (2011)].

· Edge localized mode (ELM) control: Demonstrated for the first time ELM pacing by vertical jogs in a ST [S.P. Gerhardt, et al, NF 50, 064015 (2010)].

· Error field correction: Helped develop the optimal n>1 error field correction strategy for NSTX, resulting in significantly improved routine operation [S. P. Gerhardt, et al, Plasma Phys. Control. Fusion, 52, 104003 (2010)].

· Neoclassical tearing modes: Used soft x-ray emission to understand the coupled mode structure of m/n=1/1+2/1 kink/tearing modes in NSTX high-performance discharges. Showed importance of rotation shear effects on the 2/1 NTM offset threshold [S.P. Gerhardt, et al, NF 49, 032003 (2009)].

· Novel FRC formation: Developed a new FRC formation scheme using co-helicity merging of noble-gas formed spheromaks + solenoid induction [S.P. Gerhardt, et al, NF 48, 032001 (2008)].

· FRC stability: Developed FRC equilibria that are stable to all n=1 modes (tilt, shift, axial) by proper shaping of the equilibrium field and (limited) use of passive conductors. [S.P. Gerhardt, et al, Phys. Plasmas 13, 112058 (2006)].

· FRC sustainment: Developed long-lived FRC sustained by solenoid induction and stabilized to n=2-4 modes by FLR and resistive effects [S. P. Gerhardt, et al, PRL. 99, 245003 (2007)].

· Flow damping in a quasi-symmetric stellarator: Demonstrated the reduction in flow damping with quasi-symmetry compared to traditional stellarators, using a novel interpretation of Mach probes and a new calculation of the non-orthogonal Hamada coordinate basis vectors to allow theory/experiment comparisons [S. P. Gerhardt, et al, PRL. 94, 015002 (2005)].

Leadership, Responsibilities & Service:

· Published recent first-author papers in numerous critical areas of spherical tokamak physics, including advanced scenario modeling & experimental development, ELM pacing, error field correction, plasma stability, plasma control, and disruption physics & detection.

· Referee for Nuclear Fusion, Physical Review Letters, Physics of Plasmas, Plasma Physics and Controlled Fusion, Review of Scientific Instruments, and Fusion Science & Technology.

· Cognizant physicist for mission-critical NSTX magnetic diagnostics and plasma control algorithms.

· Deputy leader for the NSTX Macroscopic Stability topical science group (2008).

· Leader of the NSTX Advanced Scenarios and Control topical science group (2009-present), and author of corresponding chapter in NSTX-U 2014-2019 5-year research plan (2013).

· Member of the DIII-D Physics Advisory Committee (2011-present).

· Member of the ITPA (International Tokamak Physics Activity) Integrated Operation Scenarios (IOS) group (2009-present).

· US Burning Plasma Organization, deputy (2012) and leader (2013) for the Integrated Scenarios topical group.

· National coordinator for the 2013 Three Fusion Facility Joint Research Target (JRT).

· Reviewer of major DOE proposals.

· Functioned as a primary interface between PPPL engineering and NSTX physics in areas of plasma control, diagnostics, magnetic materials, and the NSTX device configuration.

· Member of thesis committees in both MAE and Astrophysics departments.

· PPPL tour guide.

Peer Reviewed First Author Journal Publications:

1. S.P. Gerhardt, D.T. Anderson, J.M. Canik, and L. Owen, H_a detector system for the Helically Symmetric Experiment, Rev. Sci. Instrum. 75, 2981 (2004).

2. S. P. Gerhardt, J.N. Talmadge, J.M. Canik, and D.T. Anderson, Experimental evidence of reduced plasma flow damping with quasisymmetry, Phys. Rev. Lett. 94, 015002 (2005).

3. S.P. Gerhardt, D.T. Anderson, F.S.B. Anderson, and J.N. Talmadge, Electrode and Langmuir probe tools used for flow damping studies in the Helically Symmetric Experiment, Rev. Sci. Instrum. 75, 4621 (2004).

4. S.P. Gerhardt, D.T. Anderson, and J.N. Talmadge, Calculations of neoclassical viscous damping on flux surfaces near magnetic islands in the Helically Symmetric Experiment, Phys. Plasmas 12, 012504 (2005).

5. S.P. Gerhardt, J. N. Talmadge, J.M. Canik, and D.T. Anderson, Measurements and modeling of plasma flow damping in the Helically Symmetric Experiment, Phys. Plasmas 12, 056116 (2005).

6. S.P. Gerhardt, M. Inomoto, E. Belova, M. Yamada, H. Ji, Y. Ren, and A. Kuritsyn, Equilibrium and stability studies of oblate field reversed configurations in the Magnetic Reconnection Experiment, Phys. Plasmas 13, 112508 (2006).)

7. S. P. Gerhardt, E.V. Belova, M. Yamada, H. Ji, M. Inomoto, Y. Ren, and B. McGeehan, Inductive sustainment of a field-reversed configuration stabilized by shaping, magnetic diffusion, and finite-Larmor-radius effects, Phys. Rev. Lett. 99, 245003 (2007).

8. S.P. Gerhardt, E.V. Belova, M. Yamada, H. Ji, M. Inomoto, Y. Ren and B. McGeehan, New Method for inductively forming an oblate field reversed configuration from a spheromak, Nuclear Fusion 48, 032001 (2008).

9. S. P. Gerhardt, E.V. Belova, M. Yamada, H. Ji, M. Inomoto, C.M. Jacobson, R. Maqueda, B. McGeehan, and Y. Ren, Inductive sustainment of oblate field-reversed configurations with the assistance of magnetic diffusion, shaping, and finite-Larmor radius stabilization, Phys. Plasmas 15, 022502 (2008).

10. S.P. Gerhardt, E.V. Belova, M. Yamada, H. Ji, Y. Ren, B. McGeehan, and M. Inomoto, Field-reversed configuration formation scheme utilizing a spheromak and solenoid induction, Phys. Plasmas 15, 032503 (2008).

11. S.P. Gerhardt, J.E. Menard, and the NSTX Team, Characterization of the plasma current quench during disruptions in the National Spherical Torus Experiment, Nuclear Fusion 49, 025002 (2009).

12. S.P. Gerhardt, D.P. Brennan, R. Buttery, R.J. La Haye, S. Sabbagh, E. Strait, M. Bell, R. Bell, E. Fredrickson, D. Gates, B. LeBlanc, J. Menard, D. Stutman, K. Tritz and H. Yuh, Relationship between onset thresholds, trigger types and rotation shear for the m/n = 2/1 neoclassical tearing mode in a high-β spherical torus, Nuclear Fusion 49, 032003 (2009).

13. S.P. Gerhardt, J-W. Ahn, J.M. Canik, R. Maingi, R. Bell, D. Gates, R. Goldston, R. Hawryluk, B.P. Le Blanc, J. Menard, A.C. Sontag, S. Sabbagh and K. Tritz, First observation of ELM pacing with vertical jogs in a spherical torus, Nuclear Fusion 50, 064015 (2010).

14. S. P. Gerhardt, J. E. Menard, J.-K. Park, R. Bell, D. A. Gates, B. P. Le Blanc, S. A. Sabbagh and H. Yuh, Observation and correction of non-resonant error fields in NSTX, Plasma Phys. Control. Fusion, 52, 104003 (2010).

15. S.P. Gerhardt, E. Fredrickson, D. A. Gates, et al., Calculation of the non-inductive current profile in high-performance NSTX plasmas, Nuclear Fusion 51, 033004 (2011).

16. S.P. Gerhardt, et al., Recent progress toward an advanced spherical torus operating point in NSTX, Nuclear Fusion 51, 083047 (2011).

17. S.P. Gerhardt, D. Mastrovito, M.G. Bell, M. Cropper, D. A Gates, E. Kolemen, J.

Lawson, B. Marsala, J.E. Menard, D. Mueller, T. Stevenson, Implementation of β_N Control in the National Spherical Torus Experiment, Fusion Sci. Tech. 61, 11 (2012).

18. S. P. Gerhardt, E. Fredrickson, L. Guttadora, R. Kaita, H. Kugel, J. Menard, and H. Takahashi, Techniques for the measurement of disruption halo currents in the National Spherical Torus Experiment, Rev. Sci. Instrum. 82, 103502 (2011).

19. S.P. Gerhardt, J. Menard, S. Sabbagh and F. Scotti, Characterization of disruption halo currents in the National Spherical Torus Experiment, Nuclear Fusion 52, 063005 (2012).

20. S.P. Gerhardt, R. Andre, and J.E. Menard, Exploration of the Equilibrium Operating Space for NSTX-Upgrade, Nuclear Fusion 52, 083020 (2012).

21. S.P. Gerhardt, R.E. Bell, A. Diallo, D. Gates^, B.P. LeBlanc, J.E. Menard, D. Mueller, S.A. Sabbagh, V. Soukhanovskii, K. Tritz, H. Yuh,Disruptions, Disruptivity, and Safer Operating Windows in the High-b Spherical Torus NSTX, Nuclear Fusion 53, 043020 (2013).

22. S.P. Gerhardt, Dynamics of the Disruption Halo Current Toroidal Asymmetry in NSTX, Nuclear Fusion 53, 023005 (2013).

Note: This paper was selected as a Nuclear Fusion “LabTalk” highlight in March, 2013

23. S. P. Gerhardt, D. S. Darrow, R. E. Bell, B. P. LeBlanc, J.E. Menard, D. Mueller, A. L. Roquemore, S.A. Sabbagh, H. Yuh^. Detection of Disruptions in the High-b Spherical Torus NSTX, Nuclear Fusion 53, 063021 (2013).

Peer Reviewed Co-Authored Journal Publications:

1. B.E. Chapman, J.K. Anderson, T.M. Biewer, D.L. Brower, S. Castillo, P.K. Chattopadhyay, C.S. Chaing, D. Craig, D.J. Den Hartog, G. Fiksel, P.W. Fontanna, C.B. Forest, S. P. Gerhardt, A.K. Hansen, D. Holly, Y. Jiang, N.E. Lanier, S.C. Prager, J.C. Reardon, and J.S. Sarff, Reduced edge instability and improved confinement in the MST reversed-field pinch, Phys. Rev. Lett. 87, 205001 (2001).

2. N.E. Lanier, S.P. Gerhardt, and D.J. Den Hartog, Low-cost, robust, filtered spectrometer for absolute intensity measurements in the soft X-ray region, Rev. Sci. Instrum. 72, 1188 (2001).

3. D.T. Anderson, A.F. Almagri, F.S.B. Anderson, S.P. Gerhardt, J. Radder and J.N. Talmadge, Initial experimental results from HSX, J. Plasma and Fusion Research 78, 209 (2002).

4. C. Deng, D.L. Brower, W.X. Ding, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, S.P. Gerhardt, P. Probert, and J.N. Talmadge, First results from the Multichannel interferometer system on HSX, Rev. Sci. Instrum. 74, 1625 (2003).

5. K.M. Likin, A. Abdou, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, D. Brower, J. Canik, C. Deng, S.P. Gerhardt, W. Guttenfelder, S. Oh, J. Radder, V. Sakaguchi, J. Schmitt, J. Tabora, J.N. Talmadge, and K. Zhai, Comparison of electron cyclotron heating results in the Helically Symmetric Experiment with and without quasi-symmetry, Plasma Phys. Control Fusion 45, A133 (2003).

6. J.N. Talmadge, K.M. Likin, A. Abdou, A. Almagri, D.T. Anderson, F.S.B. Anderson, J. Canik, C. Deng, S.P. Gerhardt, K. Zhai, ASTRA modeling of electron cyclotron heating in HSX, Fusion Science and Technology 46, 255 (2004).

7. J.N. Talmadge, and S.P. Gerhardt Numerical calculation of the Hamada basis vectors for three-dimensional toroidal magnetic configurations, Phys. Plasmas 12, 072513 (2005).

8. Y. Ren, M. Yamada, S.P. Gerhardt, H. Ji, R. Kulsrud, and A. Kuritsyn, Experimental verification of the Hall effect during magnetic reconnection in a laboratory plasma, Phys. Rev. Lett. 95, 055003 (2005).

9. A. Kuritsyn, M. Yamada, S.P. Gerhardt, H. Ji, and Y. Ren, Experimental measurements of the parallel and transverse Spitzer resistivities during collisional magnetic reconnection, Phys. Plasmas, 13, 055703 (2006).

10. M. Yamada, Y. Ren, H. Ji, J. Breslau, S.P. Gerhardt, R. Kulsrud, and A. Kuritsyn, Experimental study of two fluid effects on magnetic reconnection in a laboratory plasma with variable collisionality, Phys. Plasmas 13, 052119 (2006).

11. M. Inomoto, S.P. Gerhardt, M. Yamada, H. Ji, E. Belova, Y. Ren, and A. Kuritsyn, Coupling between global geometry and the local Hall effect leading to reconnection-layer symmetry breaking, Phys. Rev. Lett. 97, 135002 (2006).

12. M. Yamada, H. Ji, S.P. Gerhardt, E.V. Belova, R.C Davison, and D.R. Mikkelsen, A self-organized plasma with induction, reconnection, and injection techniques: the SPIRIT concept for field reversed configuration research, Plasma and Fusion Research 2, 004 (2007).

13. A. Kuritsyn, H. Ji, S.P. Gerhardt, Y. Ren, and M. Yamada, Effect of global boundary and local collisionality on magnetic reconnection in a laboratory plasma, Geophys. Rev. Lett. 34, L16106 (2007).

14. H. Ji, E. Belova, S.P. Gerhardt, and M. Yamada, Recent advances in the SPIRIT (Self-organized Plasma with Induction, Reconnection, and Injection Techniques) concept, Journal of Fusion Energy 26, 93 (2007).

15. Y. Ren, M. Yamada, H. Ji, S. P. Gerhardt, and R. Kulsrud, Identification of the electron-diffusion region during magnetic reconnection in a laboratory plasma, Phys. Rev. Lett 101, 085003 (2008).

16. Y. Ren, M. Yamada, H. Ji, S. Dorfman, S. P. Gerhardt, and R. Kulsrud, Experimental study of the Hall effect and electron diffusion region during magnetic reconnection in a laboratory plasma, Phys. Plasmas 15, 082113 (2008).

17. H. Ji, Y. Ren, M. Yamada, S. Dorfman, W. Daughton, S. P. Gerhardt, New insights into the dissipation in the electron layer during magnetic reconnection, Geophys. Res. Lett., 35, L13106 (2008).

18. R. Raman, T.R. Jarboe, D. Mueller, B.A. Nelson, M.G. Bell, R. Bell, D. Gates, S. Gerhardt, J. Hosea, R. Kaita, H. Kugel, B. LeBlanc, R. Maingi, R. Maqueda, J. Menard, M. Nagata, M. Ono, S. Paul, L. Roquemore, S. Sabbagh, V. Soukhanovskii and G. Taylor, Solenoid-free plasma startup in NSTX using transient CHI, Nuclear Fusion 49, 065006 (2009).

19. J.-K. Park, A. H. Boozer, J. E. Menard, A. M. Garofalo, M. J. Schaffer, R. J. Hawryluk, S. M. Kaye, S. P. Gerhardt, S. A. Sabbagh, and NSTX Team, Importance of plasma response to nonaxisymmetric perturbations in tokamaks, Phys. Plasmas 16, 056115, (2009).

20. H.W. Kugel, M. Bell, L. Berzak, A. Brooks, R. Ellis, S. P. Gerhardt, H. Harjes, R. Kaita, J. Kallman, R. Maingi, R. Majeski, D. Mansfield, J. Menard, R.E. Nygren, V. Soukhanovskii, D. Stotler, P. Wakeland, L.E. Zakharov, Physics design requirements for the National Spherical Torus liquid lithium divertor, Fusion Eng. And Design 84, 1125, (2009).

21. R. Maingi, T. H. Osborne, B. P. LeBlanc, R. E. Bell, J. Manickam, P. B. Snyder, J. E. Menard, D. K. Mansfield, H. W. Kugel, R. Kaita, S. P. Gerhardt, S. A. Sabbagh, F. A. Kelly, and the NSTX research team, Edge-Localized-Mode Suppression through Density-Profile Modification with Lithium-Wall Coatings in the National Spherical Torus Experiment, Phys. Rev. Lett. 103, 075001 (2009).

22. J.-K. Park, A. H. Boozer, J. E. Menard, S. P. Gerhardt, and S. A. Sabbagh, Shielding of external magnetic perturbations by torque in rotating tokamak plasmas, Phys. Plasmas 16, 082512 (2009).

23. D. A. Gates et al, Overview of results from the National Spherical Torus Experiment, Nuclear Fusion 49, 104016 (2009).

24. M.G. Bell, H.W. Kugel, R. Kaita, L.E. Zakharov, H. Schneider, B.P. LeBlanc, D. Mansfield, R.E. Bell, R. Maingi, S. Ding, S.M. Kaye, S.F. Paul, S.P. Gerhardt, J.M. Canik, J.C. Hosea, G. Taylor and the NSTX Research Team, Plasma response to lithium-coated plasma-facing components in the National Spherical Torus Experiment, Plasma Phys. Control. Fusion 51, 124054 (2009).

25. H.W. Kugel, D. Mansfield, R. Maingi, M.G. Bell, R.E. Bell, J.P. Allain, D. Gates, S. Gerhardt, R. Kaita, J. Kallman, S. Kaye, B. LeBlanc, R. Majeski, J. Menard, D. Mueller, M. Ono, S. Paul, R. Raman, A.L. Roquemore, P.W. Ross, et al, Evaporated lithium surface coatings in NSTX, J. Nucl. Mat. 390, 1000 (2009).

26. S.A. Sabbagh, J.W. Berkery, R.E. Bell, J.M. Bialek, S.P. Gerhardt, J.E. Menard, R. Betti, D.A. Gates, B. Hu, O.N. Katsuro-Hopkins, B.P. LeBlanc, F.M. Levinton, J. Manickam, K. Tritz and H. Yuh, Advances in global MHD mode stabilization research on NSTX, Nuclear Fusion 50, 025020 (2010).

27. J. M. Canik, R. Maingi, T. E. Evans, R. E. Bell, S. P. Gerhardt, B. P. LeBlanc, J. Manickam, J. E. Menard, T. H. Osborne, J.-K. Park, S. F. Paul, P. B. Snyder, S. A. Sabbagh, H. W. Kugel, and E. A. Unterberg (the NSTX Team), On Demand Triggering of Edge Localized Instabilities Using External Nonaxisymmetric Magnetic Perturbations in Toroidal Plasmas, Phys. Rev. Lett. 104, 045001 (2010).

28. J. W. Berkery, S. A. Sabbagh, R. Betti, B. Hu, R. E. Bell, S. P. Gerhardt, J. Manickam, and K. Tritz, Resistive Wall Mode Instability at Intermediate Plasma Rotation, Phys. Rev. Lett. 104, 035003 (2010).

29. R. Raman, D. Mueller, B. A. Nelson, T. R. Jarboe, S. Gerhardt, H. W. Kugel, B. LeBlanc, R. Maingi, J. Menard, M. Ono, S. Paul, L. Roquemore, S. Sabbagh, and V. Soukhanovskii, Demonstration of Tokamak Ohmic Flux Saving by Transient Coaxial Helicity Injection in the National Spherical Torus Experiment, Phys. Rev. Lett. 104, 095003 (2010).

30. J.M. Canik, R. Maingi, T.E. Evans, R.E. Bell, S.P. Gerhardt, H.W. Kugel, B.P. LeBlanc, J. Manickam, J.E. Menard, T.H. Osborne, J.-K. Park, S. Paul, P.B. Snyder, S.A. Sabbagh, E.A. Unterberg and the NSTX team, ELM destabilization by externally applied non-axisymmetric magnetic perturbations in NSTX, Nuclear Fusion 50, 034012 (2010).

31. J.E. Menard, R.E. Bell, D.A. Gates, S.P. Gerhardt, J.-K. Park, S.A. Sabbagh, J.W. Berkery, A. Egan, J. Kallman, S.M. Kaye, B. LeBlanc, Y.Q. Liu, A. Sontag, D. Swanson, H. Yuh, W. Zhu and the NSTX Research Team, Progress in understanding error-field physics in NSTX spherical torus plasmas, Nuclear Fusion 50, 045008 (2010).

32. J.M. Canik, A.C. Sontag, R. Maingi, R. Bell, D.A. Gates, S.P. Gerhardt, H.W. Kugel, B.P. LeBlanc, J. Menard, S. Paul, S. Sabbagh and V.A. Soukhanovskii, Progress in the development of ELM pace-making with non-axisymmetric magnetic perturbations in NSTX,

Nuclear Fusion 50, 064016 (2010).

33. R. Maingi, S.M. Kaye, R.E. Bell, T.M. Biewer, C.S. Chang, D.A. Gates, S.P. Gerhardt, J. Hosea, B.P. LeBlanc, H. Meyer, D. Mueller, G-Y. Park, R. Raman, S.A. Sabbagh, T.A. Stevenson and J.R. Wilson, Overview of L–H power threshold studies in NSTX, Nuclear Fusion 50, 061010 (2010).

34. I.T. Chapman, R.J. Buttery, S. Coda, S. Gerhardt, J.P. Graves, D.F. Howell, A. Isayama, R.J. La Haye, Y. Liu, P. Maget, M. Maraschek, S. Sabbagh, O. Sauter, the ASDEX Upgrade, DIII-D, HL-2A, JT-60U , MAST , NSTX , TCV , Tore Supra Teams and JET-EFDA Contributors, Empirical scaling of sawtooth period for onset of neoclassical tearing modes, Nuclear Fusion 50, 102001 (2010).

35. M. Ono, M.G. Bell, R.E. Bell, R Kaita, H.W. Kugel, B.P. Leblanc, J.M. Canik, S. Diem, S.P. Gerhardt, J. Hosea, S. Kaye, D. Mansfield, R. Maingi, J. Menard, S.F. Paul, R. Raman, S. Sabbagh, C.H. Skinner, V. Soukhanovskii, G. Taylor, Implications of NSTX lithium results for magnetic fusion research, Fusion Eng. Design. 85, 882 (2010).

36. E. Kolemen, D.A. Gates, C.W. Rowley, N.J. Kasdin, J. Kallman, S. Gerhardt, V. Soukhanovskii and D. Mueller, Strike point control for the National Spherical Torus Experiment (NSTX), Nuclear Fusion 50, 105010 (2010).

37. J. W. Berkery, S. A. Sabbagh, H. Reimerdes, R. Betti, B. Hu, R. E. Bell, S. P. Gerhardt, J. Manickam, and M. Podestà, The role of kinetic effects, including plasma rotation and energetic particles, in resistive wall mode stability, Phys. Plasmas 17, 082504 (2010).

38. R. J. La Haye, D. P. Brennan, R. J. Buttery, and S. P. Gerhardt, Islands in the stream: The effect of plasma flow on tearing stability, Phys. Plasmas 17, 056110 (2010).

39. R. Maingi, R. E. Bell, J. M. Canik, S. P. Gerhardt, S. M. Kaye, B. P. LeBlanc, T. H. Osborne, M. G. Bell, E. D. Fredrickson, K. C. Lee, J. E. Menard, J.-K. Park, and S. A. Sabbagh, Triggered Confinement Enhancement and Pedestal Expansion in High-Confinement-Mode Discharges in the National Spherical Torus Experiment Phys. Rev. Lett. 105, 135004 (2010).

40. D. Mastrovito, D. Gates, S.P. Gerhardt, J. Lawson, C. Ludescher-Furth, R. Marsala, Plasma control system upgrade and increased plasma stability in NSTX, Fus. Eng. Design 85, 447 (2010).

41. V.A. Soukhanovskii, J.-W. Ahn, R.E. Bell, D.A. Gates, S. Gerhardt, R. Kaita, E. Kolemen, H.W. Kugel, B.P. LeBlanc, R. Maingi, R. Maqueda, A. McLean, J.E. Menard, D.M. Mueller, S.F. Paul, R. Raman, A.L. Roquemore, D.D. Ryutov, H.A. Scott, “Snowflake” divertor configuration in NSTX, J. Nucl. Mat. 415, S365 (2011)

42. V. A. Soukhanovskii, J.-W. Ahn, R.E. Bell, D.A. Gates, S.P. Gerhardt, et al. Taming the plasma material interface with the "snowflake" divertor in NSTX, Nuclear Fusion 51, 012001 (2011).

43. L. Delgado-Aparicio, D. Stutman, S. A. Sabbagh, R. E. Bell, J. W. Berkery, K. Tritz, S P Gerhardt, B. LeBlanc, M. Finkenthal, J. P. Levesque, K. C. Lee, J. Menard, S. Paul and L. Roquemore, Soft X-ray measurements of resistive wall mode behavior in NSTX, Plasma Phys. Control. Fusion 53, 035005 (2011).

44. M.A. Jaworski, S.P. Gerhardt, N.B. Morley, T. Abrams, R. Kaita, J. Kallman, H. Kugel, R. Majeski, D.N. Ruzik, Macroscopic motion of liquid metal plasma facing components in a diverted plasma, J. Nucl. Mat. 415, S985 (2011)

45. H.W. Kugel, M.G. Bell, J.P. Allain, R.E. Bell, S. Ding, S.P. Gerhardt, M.A. Jaworski, R. Kaita, J. Kallman, S.M. Kaye, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, D.K. Mansfield, D. Mueller, R. Nygren, S.F. Paul, R. Raman, A.L. Roquemore, et al., NSTX plasma response to lithium coated divertor, J. Nucl. Mat. 415, S400 (2011).

46. R. Raman, D. Mueller, T. R. Jarboe, B. A. Nelson, M. G. Bell, S. Gerhardt, B. LeBlanc, J. Menard, M. Ono, L. Roquemore, and V. Soukhanovskii, Experimental demonstration of tokamak inductive flux saving by transient coaxial helicity injection on national spherical torus experiment, Phys. Plasmas 18, 092504 (2011).

47. J. W. Berkery, S. A. Sabbagh, R. Betti, R. E. Bell, S. P. Gerhardt, B. P. LeBlanc, and H. Yuh, Effect of Collisionality on Kinetic Stability of the Resistive Wall Mode, Phys. Rev. Lett. 106, 075004 (2011).

48. A.C. Sontag, J.M. Canik, R. Maingi, J. Manickam, P.B. Snyder, R.E. Bell, S.P. Gerhardt, S. Kubota, B.P. LeBlanc, D. Mueller, T.H. Osborne and K.L. Tritz, Pedestal characterization and stability of small-ELM regimes in NSTX, Nuclear Fusion 51, 103022 (2011).

49. R. Raman, et al., Overview of Recent Results from NSTX, Nuclear Fusion 51, 094011 (2011).

50. L. Delgado-Aparicio, D. Stutman, K. Tritz, F. Volpe, K.L. Wong, R. Bell, M. Finkenthal, E. Fredrickson, S.P. Gerhardt, S. Kaye, B. LeBlanc, J. Menard, S. Paul and L. Roquemore, Impurity transport experiments and effects on MHD in the National Spherical Torus Experiment (NSTX), Nuclear Fusion 51, 083047 (2011).

51. R.J. Buttery, S. Gerhardt, R.J. La Haye, Y.Q. Liu, H. Reimerdes, S. Sabbagh, M.S. Chu, T.H. Osborne, J.-K. Park, R.I. Pinsker, E.J. Strait, J.H. Yu and the DIII-D and NSTX Teams, The impact of 3D fields on tearing mode stability of H-modes, Nuclear Fusion 51, 073016 (2011).

52. J.A. Breslau, M.S. Chance, J. Chen, G.Y. Fu, S. Gerhardt, N. Gorelenkov, S.C. Jardin and J. Manickam, Onset and saturation of a non-resonant internal mode in NSTX and implications for AT modes in ITER, Nuclear Fusion 51, 063027 (2011).

53. R. Maingi, D.P. Boyle, J.M. Canik, S.M. Kaye, C.H. Skinner, J.P. Allain, M.G. Bell, R.E. Bell, S.P. Gerhardt, et al., The effect of progressively increasing lithium coatings on plasma discharge characteristics, transport, edge profiles and ELM stability in the National Spherical Torus Experiment, Nuclear Fusion 52, 083001 (2012).

54. J.M. Canik, S.P. Hirshman, R. Sanchez, R. Maingi, J.-W. Ahn, R.E. Bell, A. Diallo, S.P. Gerhardt, B.P. LeBlanc, J.E. Menard, J.-K. Park, M. Podesta and S.A. Sabbagh, First use of three-dimensional equilibrium, stability and transport calculations for interpretation of ELM triggering with magnetic perturbations in NSTX, Nuclear Fusion 52, 054004 (2012).

55. Jong-Kyu Park, Jonathan E. Menard, Stefan P. Gerhardt, Richard J. Buttery, Steve A. Sabbagh, Ronald E. Bell and Benoit P. LeBlanc, Sensitivity to Error Fields in NSTX High-b Plasmas, Nuclear Fusion 52, 023004 (2012).

56. S.S. Medley, Ya.I. Kolesnichenko, Yu.V. Yakovenko, R.E. Bell, A. Bortolon, N.A. Crocker, D.S. Darrow, A. Diallo, C.W. Domier, R.J. Fonck, E.D. Fredrickson, S.P. Gerhardt, et al. Investigation of a transient energetic charge exchange flux enhancement ('spike-on-tail') observed in neutral-beam-heated H-mode discharges in the National Spherical Torus Experiment, Nuclear Fusion 52, 013014 (2012).

57. E. Kolemen, D.A. Gates, S. Gerhardt, R. Kaita, H. Kugel, D. Mueller, C. Rowley and V. Soukhanovskii, Plasma modeling results and shape control improvements for NSTX, Nuclear Fusion 51, 113024 (2012).

58. J.E. Menard, S.P. Gerhardt, M. Bell, et al., Overview of the Physics and Engineering Design of NSTX Upgrade, Nuclear Fusion 52, 083015 (2012).

59. R. J. La Haye, R. J. Buttery, S. P. Gerhardt, S. A. Sabbagh, and D. P. Brennan, Aspect ratio effects on neoclassical tearing modes from comparison between DIII-D and National Spherical Torus Experiment, Phys. Plasmas 19, 062506 (2012).

60. V.A. Soukhanovskii, Stefan Gerhardt, Robert Kaita, Adam McLean, and Roger Raman, Diagnostic Options for Radiative Divertor Feedback Control on NSTX-U, Rev. Sci. Instrum. 83, 10D716 (2012).

61. R. Raman, T. Abrams, T.R. Jarboe, H.W. Kugel, D. Mueller, D. P. Stotler, S.P. Gerhardt, M.G. Bell, J.E. Menard, & M. Ono, Massive Gas Injection Plans for Disruption Mitigation Studies in NSTX-U, IEEE Transactions on Fundamentals and Materials 132, 468 (2012).

62. Janardhan Manickam, Allen Boozer, and Stefan Gerhardt, Kink modes and surface currents associated with vertical displacement events, Phys. Plasmas 19, 082103 (2012).

63. V. A. Soukhanovskii, R.E. Bell, A. Diallo, S. Gerhardt, et al., Snowflake divertor configuration studies in National Spherical Torus Experiment, Phys. Plasmas 19, 082504 (2012).

64. R. J. Perkins, J. C. Hosea, G. J. Kramer, J.-W. Ahn, R. E. Bell, A. Diallo, S. Gerhardt, T. K. Gray, et al., High-Harmonic Fast-Wave Power Flow along Magnetic Field Lines in the Scrape-Off Layer of NSTX, Phys. Rev. Lett. 109, 045001 (2012).

65. H.W. Kugel, J.P. Allain, M.G. Bell, R.E. Bell, A. Diallo, R. Ellis, S.P. Gerhardt, et al., NSTX plasma operation with a Liquid Lithium Divertor, Fusion Engineering and Design 87, 1724 (2012).

66. M. Ono, M.G. Bell, R. Kaita, R. H.W. Kugel, J.W. Ahn, J. P. Allain, D. Battaglia, R.E., Bell, J.M. Canik, S. Ding, S. Gerhardt, et al., Recent progress of NSTX lithium program and opportunities for magnetic fusion research, Fusion Eng. Design 87, 1770 (2012).

67. E.D. Fredrickson, N.A. Crocker, D.S. Darrow, N.N. Gorelenkov, G.J. Kramer, S. Kubota, M. Podesta, R.B. White, A. Bortolon, S.P. Gerhardt, R.E. Bell, A. Diallo, B. LeBlanc, F.M. Levinton and H. Yuh , Fast-ion energy loss during TAE avalanches in the National Spherical Torus Experiment, Nuclear Fusion 53, 013006 (2013).

68. S.M. Kaye, S. Gerhardt, W. Guttenfelder, R. Maingi, R.E. Bell, A. Diallo, B.P. LeBlanc, and M. Podesta, The dependence of H-mode energy confinement and transport on collisionality in NSTX, Nuclear Fusion 53, 063005 (2013).

69. R.J. Perkins, J.-W. Ahn, R.E. Bell, A. Diallo, S. Gerhardt, T.K. Gray, et al., Fast Wave Power Flow Along SOL Field Lines in NSTX and the Associated Power Deposition Profile Across the SOL in Front of the Antenna, submitted to Nuclear Fusion (2012).

70. R. Raman, D. Mueller, S.C. Jardin, T.R. Jarboe, B.A. Nelson, M.G. Bell, S.P. Gerhardt, E.B. Hooper, et al., Non-inductive Plasma Start-up in NSTX Using Transient CHI, accepted for publication in Nuclear Fusion (2013).

71. D.J. Battaglia, C.S. Chang, S.M. Kaye, K. Kim, S. Ku, R. Maingi, R.E. Bell, A. Diallo, S. Gerhardt, B.P. LeBlanc, J. Menard, And the NSTX Team, Dependence of the L-H Transition on X-point Geometry and Divertor Recycling on NSTX, submitted to Nuclear Fusion (2012).

72. S.A. Sabbagh, et al., Overview of Physics Results from the National Spherical Torus Experiment, submitted to Nuclear Fusion (2012).

73. E.D. Fredrickson, N. N. Gorelenkov, M. Podesta, A. Bortolon, S. P. Gerhardt, R. E. Bell, A. Diallo, B. LeBlanc, F. M. Levinton, H. Yuh, Characteristics of short wavelength Compressional Alfvén Eigenmodes, submitted to Nuclear Fusion (2012).

74. Kimin Kim, Jong-Kyu Park, Gerrit J. Kramer, Allen H. Boozer, Jonathan E. Menard, Stefan P. Gerhardt, Nikolas C. Logan, Keith H. Burrell, and Andrea M. Garofalo, Calculation of neoclassical toroidal viscosity with a particle simulation in the tokamak magnetic braking experiments, submitted to Nuclear Fusion (2012).

75. F. Scotti, V.A. Soukhanovskii, R.E. Bell, S. Gerhardt, W. Guttenfelder, S. Kaye, R. Andre, R. Kaita, B.P. LeBlanc, M. Podesta and the NSTX Team, Study of Core Transport of Intrinsic Impurities in ELM-free NSTX Discharges with Lithium Wall Conditioning, submitted to Nuclear Fusion (2012).

76. M.A. Jaworski, T. Abrams, J.P. Allain, M.G. Bell, R.E. Bell, A. Diallo, T.K. Gray, S.P. Gerhardt, R. Kaita, H.W. Kugel, B.P. LeBlanc, R. Maingi, A.G. McLean, J. Menard, R. Nygren, M. Ono, M. Podesta, A.L. Roquemore, S.A. Sabbagh, F. Scotti, C.H. Skinner, V.A. Soukhanovskii, D.P. Stotler, and the NSTX Team, Liquid Lithium Divertor Characteristics and Plasma-Material Interactions in NSTX High-Performance Plasmas, submitted to Nuclear Fusion (2012).

77. M. Ono, M.A. Jaworski, R. Kaita, H.W. Kugel, J-W. Ahn, J.P. Allain, M.G. Bell, R.E. Bell, D. Clayton, J.M. Canik, S. Ding, S. Gerhardt, T.K. Gray, et al. Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-Relevant Liquid-Lithium Based Divertor Development, submitted to Nuclear Fusion (2012).

78. J.-K.Park, et al., Observation of EHOs in NSTX and theoretical study of its active control using HHFW antenna, submitted to Nuclear Fusion (2012).

79: R. Kaita, et al., Characterization of fueling NSTX H-mode plasmas diverted to a liquid lithium divertor, accepted by The Journal of Nuclear Materials (2013).

80: E. D. Fredrickson, N. N. Gorelenkov, M. Podesta, A. Bortolon, N. A. Crocker, S. P. Gerhardt, R. E. Bell, A. Diallo, B. LeBlanc, F. M. Levinton, and H. Yuh, Non-linear modulation of short wavelength compressional Alfvén eigenmodes, Phys. Plasmas 20, 042112 (2013).

81: V. Soukhanovskii, R.E. Bell, A. Diallo, S. Gerhardt, S. Kaye, et al., Advanced Divertor Configurations with Large Flux Expansion, accepted by The Journal of Nuclear Materials (2013).

82: M. Podesta, E.D. Fredrickson, S.P. Gerhardt, G. Kramer, N. Gorelenkov, and R. White, Properties of Alfvèn Eigenmodes in the TAE range on the National Spherical Torus Experiment-Upgrade, submitted to Physics of Plasmas (2013).

Significant Presentations:

1. Measurements and modeling of electrode-induced plasma flows in HSX, Joint US-European Transport Task Force Meeting, Madison, Wisconsin, 2003.

2. Studies of Bias Induced Plasma Flows in HSX, 14^thInternational Stellarator Workshop, Greifswald, Germany, 2003.

3. Measurements and Modeling of Electrode Biased Discharges in the HSX Stellarator. Joint Meeting of US-Japan Workshop and Kyoto University 21^st COE Symposium on "New Approaches in Plasma Confinement Experiments in Helical Systems", Kyoto, 2004.

4. Progress and Plans for FRC Studies in MRX-FRC, US-Japan Exchange 2004: New Directions and Physics for Compact Toroids, Santa Fe, New Mexico, 2004.

5. Measurements and Modeling of Electrode Biased Discharges in the HSX Stellarator, Invited talk at the 20th IAEA Fusion Energy Conference, Vilamoura, Portugal, 2004.

6. Measurements and Modeling of Plasma Flow Damping in the HSX Stellarator, Invited talk at 46^th Meeting of the Division of Plasma Physics, Savannah, Georgia, 2004.

7. Reduced Neoclassical Flow Damping with Quasi-Symmetry: Measurements and Modeling from HSX, Invited talk at 47^th Meeting of the Division of Plasma Physics, Denver, Colorado, 2005.

8. Equilibrium and Stability of Oblate Free-Boundary FRCs in MRX, Innovative Confinement Concepts Conference, Austin, Texas, 2006

9. Stability of Oblate Free-Boundary FRCs in MRX, US/Japan Workshop on Compact Torus Plasmas, Swarthmore College, Philadelphia, Pennsylvania, 2007.

10. Ohmic Sustainment of Free Boundary Compact Toroids in MRX, Innovative Confinement Concepts Workshop, College Park, Maryland, 2007

11. Studies of Resonant and Non-Resonant 3-D Fields in NSTX, Invited talk at 14^th Workshop on Active Control of MHD Stability, Active MHD Control in ITER, Princeton, NJ, 2009

12. Development of High‐ Elongation, High‐ Beta Discharges for Steady State Spherical Torus Applications, 37^th European Physical Society Conference on Plasma Physics, Dublin, Ireland, 2010.

13. Tools For Developing Advanced Spherical Tokamak Plasmas in NSTX, Innovative Confinement Concepts 2010, Princeton, NJ, 2010.

14. Developing the Core Physics Scenarios For Next Step STs, Invited talk at 53^rd Annual Meeting of the APS DPP, Salt Lake City, UT, 2011.

15. Disruption Precursors and Detection in NSTX, US BPO Disruption Mitigation Workshop, San Diego, CA, 2012.

16. Disruptions in the High-b Spherical Torus NSTX, Invited talk at the 24th IAEA Fusion Energy Conference, San Diego, USA, 2012.

17. Disruption Detection and Halo Currents in NSTX, Invited talk at 17^th MHD Mode Control Workshop, New York, New York, 2012.

Seminars presented at U. of Wisconsin, U. of Maryland, Columbia University, PPPL, and MIT. Presentations at various ITPA meetings.

Presentations to the NSTX Physics Advisory Committee in 2009-2013, NSTX 5-Year Plan Review Committee in 2013.

Conference Proceedings (all with associated poster or oral presentation)

1. F.S.B. Anderson, D.T. Anderson, A.F. Almagri, J. Chen, S.P. Gerhardt, V. Sakaguchi, J. Shafii, and J.N. Talmadge, HSX Final Alignment, Assembly, and Initial Operation, 12^th International Stellarator Conference, Madison, Wisconsin, 1999.

2. D.T. Anderson, A.F. Almagri, F.S.B. Anderson, J. Chen, S.P. Gerhardt, V. Sakaguchi, J. Shafii, and J.N. Talmadge, Initial Experimental Program Plans for HSX, 12^th International Stellarator Conference, Madison, Wisconsin, 1999.

3. S.P. Gerhardt, J.N. Talmadge, D.T. Anderson, and S.A. Dettrick, Monte Carlo Diffusion Calculations and Plans for Electric Field Studies in HSX, 12^th International Stellarator Conference, Madison, Wisconsin, 1999.

4. S.P. Gerhardt, A. F. Almagri, D.T. Anderson, and J.N. Talmadge, Initial Results from Biased Electrode Experiments in HSX, Proceedings of the 13^thInternational Stellarator Workshop, Canberra, Australia, 2002.

5. J.W. Radder, D.T. Anderson, S.P. Gerhardt, A.F. Almagri, F.S.B. Anderson, J.N. Talmadge, D.L. Brower, and C. Deng, The Effects of Symmetry Breaking on Plasma Formation in the Helically Symmetric Experiment, Proceedings of the 13^thInternational Stellarator Workshop, Canberra, Australia, 2002.

6. J.N. Talmadge, D.T. Anderson, F.S.B Anderson, A.F. Almagri, C. Lechte, S.P. Gerhardt, and J. Radder, Transport in HSX ECH Plasmas at .5T, Proceedings of the 13^thInternational Stellarator Workshop, Canberra, Australia, 2002.

7. S. P. Gerhardt, A. Abdou, A. Almagri, D.T. Anderson, F.S.B. Anderson, D. Brower, J. Canik, C. Deng, W. Guttenfelder, K. Likin, S. Oh, J. Tabora, V. Sakaguchi, J. Scmitt, J.N. Talmadge, and K. Zhai, Experimental Evidence of Improved Confinement with Quasisymmetry in HSX, Proceedings of the 19^th International Conf. on Plasma Physics and Controlled Nuclear Fusion Research (Lyon, 2002), IAEA.

8. K.M. Likin, J.N. Talmadge, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, C. Deng, S.P. Gerhardt, and K. Zhai, Absorption of X-Wave at the Second Harmonic in HSX, 15th Topical Conference on Radio Frequency Power in Plasmas, Moran, 2003.

9. S.P. Gerhardt, D.T. Anderson, J. Canik, and W. Guttenfelder, Measurements and Modeling of Bias Induced Flows in the HSX Stellarator, Proceedings of the 14^thInternational Stellarator Workshop, Greifswald, Germany, 2003.

10. J. Canik, D.T. Anderson, S.P. Gerhardt, and J.N. Talmadge, Neutral Density Measurements in HSX, Proceedings of the 14^thInternational Stellarator Workshop, Greifswald, Germany, 2003.

11. J.N. Talmadge, K.M. Likin, A. Abdou, A. Almagri, D.T. Anderson, F.S.B. Anderson, J. Canik, C. Deng, S.P. Gerhardt, and K. Zhai, Electron Cyclotron Heating in Various Configurations of HSX, Proceedings of the 14^thInternational Stellarator Workshop, Greifswald, Germany, 2003.

12. S. P. Gerhardt, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, D. Brower, J.M. Canik, C. Deng, W. Gettenfelder, K.M. Likin, V. Sakaguchi, J.N. Talmadge, K. Zhai, Measurement ad Modeling of Electrode Biased Discharges in the HSX Stellarator, Proceedings of the 20^th International Conf. on Plasma Physics and Controlled Nuclear Fusion Research (Vilamoura, Portugal, 2004), IAEA.

13. J.N. Talmadge, J. Schmitt, S.P. Gerhardt, and D.T. Anderson, Quasisymmetry-Breaking and Increased Parallel Viscous Damping near Magnetic Islands in HSX, Proceedings of the 15^thInternational Stellarator Workshop, Madrid, Spain, 2005

14. S. P. Gerhardt, M. Inomoto, E.V. Belova, M. Yamada, H. Ji, and Y. Ren, Studies of Free Boundary Field-Reversed Configurations with Improved Stability in the Magnetic Reconnection Experiment, Proceedings of the 21^st International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper IC/P7-13 (Chengdu, China, 2006), IAEA.

15. E. Belova, R.C. Davidson, H. Ji, M. Yamada, and S. P. Gerhardt, Effects of Energetic Beam Ions on Stability Properties of Field Reversed Configurations, Proceedings of the 21^st International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper TH/P3-17, (Chengdu, China, 2006), IAEA.

16. S.A. Sabbagh, J.M. Bialek, R.E. Bell, J.W. Berkery, S.P. Gerhardt, O.N. Katsuro-Hopkins, J.E. Menard, R. Betti, D.A. Gates, B. Hu, B.P. LeBlanc, F.M. Levinton, J. Manickam, K. Tritz, and H. Yuh, Advances in Global MHD Mode Stabilization Research on NSTX, Proceedings of the 22^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper EX/5-1, (Geneva, Switzerland 2008), IAEA.

17. R. J. Buttery, S.P. Gerhardt, A. Isayama, R. J. La Haye, E. J. Strait, D. P. Brennan, P. Buratti, D. Chandra, S. Coda, J. De Grassie, P. Gohil, M. Gryaznevich, D. F. Howell, G. Jackson, C. Holcomb, M. Maraschek, A. Polevoi, H. Reimerdes, D. Raju, S. Sabbagh, S. Saarelma, M. Schaffer, A. Sen, the DIII-D, JT-60 and NSTX teams and JET-EFDA contributors, Multimachine Extrapolation of Neoclassical Tearing Mode Physics to ITER, Proceedings of the 22^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper IT/P6-8, (Geneva, Switzerland, 2008), IAEA.

18. D. A. Gates, et al, Overview of Results from the National Spherical Torus Experiment (NSTX), Proceedings of the 22^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper OV/3-1, (Geneva, Switzerland, 2008), IAEA.

19. R. Kaita, H. Kugel, M.G. Bell, R.Bell, J. Boedo, C. Bush, R. Ellis, D. Gates, S.P. Gerhardt, T. Gray, et al., Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX, Proceedings of the 22^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper EX/P4-9, (Geneva, Switzerland, 2008), IAEA.

20. R. Maingi, R. E. Bell, M.G. Bell, D.A Gates, E.D. Fredrickson, S.P. Gerhardt, R. Kaita, et al., Modification of edge plasma profiles in ELM-suppressed discharges with lithium coatings in NSTX, Paper P-2.175, 36^th EPS Conference on Plasma Physics, Sofia, Bulgaria, 2009.

21. L. Dalgado-Aparicio, K. Tritz, M. Finkenthal, D. Stutman, S.A. Sabbagh, J. Berkery, J. Levesque, R. Bell, S.P. Gerhardt, B.P. LeBlanc, et al. Multi-energy SXR characterization of stabilized resistive wall modes in NSTX, Paper P-2.173, 36^th EPS Conference on Plasma Physics, Sofia, Bulgaria, 2009.

22. S.P. Gerhardt, D.A. Gates, J.M. Canik, M.G. Bell, R. Bell, S, Kaye, E. Kolemen, H. Kugel, B.P. LeBlanc, R. Maingi, J.E. Menard, S.A. Sabbagh, V. Soukhanovskii, and H. Yuh Development of High-Elongation, High-Beta Discharges for Steady State Spherical Torus Applications, paper O5.126, 37^th EPS Conference on Plasma Physics, Dublin, Ireland, 2010.

23. J.M. Canik, R. Maingi, A.C. Sontag, J.-W. Ahn, R.E. Bell, D.A. Gates, S.P. Gerhardt, H.W. Kugel, B.P. LeBlanc, J.E. Menard, S.F. Paul, S.A. Sabbagh, V.A. Soukhanovskii, ELM Pacing with 3D Magnetic Perturbations in NSTX, paper P2-123, 37^th EPS Conference on Plasma Physics, Dublin, Ireland, 2010.

24. A. Sontag, J. Canik, R. Maingi, J. Manickam, P. Snyder, R. Bell, S. Gerhardt, S. Kubota, B. LeBlanc, T. Osborne, K. Tritz, Edge Stability of Small-ELM Regimes in NSTX, 37^th EPS Conference on Plasma Physics, paper P2-160, Dublin, Ireland, 2010.

25. J.M. Canik, R. Maingi, A.C. Sontag, R.E. Bell, D.A. Gates, S.P. Gerhardt, et al. Optimization of Density and Radiated Power Evolution Control using Magnetic ELM Pace-making in NSTX, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper EXC/8-1, (Daejon, Korea, 2010), IAEA.

26. L. Delgado-Aparicio, K. Tritz, D. Stutman, W. Solomon, S. Kaye, E. Fredrickson, S. Gerhardt, F. Volpe, et al., Dependence of Particle Transport on Collisionality, Rotation and MHD in NSTX, Paper EXC/P4-04, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

27. R. Maingi, M.G. Bell, R.E. Bell, J.M. Canik, E. Fredrickson, S.P. Gerhardt, R. Kaita, et al., Modification of Edge Profiles, Edge Transport, and ELM Stability with Lithium in NSTX, Paper EXD/2-2, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

28. E. Kolemen, D.A. Gates, S.P. Gerhardt, R. Kaita, et al. Plasma Modeling Results, Control Improvement for NSTX and Applications to ITER, Paper EXD/P3-18, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

29. A. Sontag, J.M. Canik, R. Maingi, J. Manickam, P. Snyder, R.E. Bell, S.P. Gerhardt, F. Kelly, et al., Pedestal Characterization and Stability of Small-ELM Regimes in NSTX, Paper EXD/P3-31, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

30. V.A. Soukhanovskii, J.W. Ahn, M.G. Bell, R.E. Bell, D.A. Gates, S.P. Gerhardt, et al., Synergy between the Innovative “Snowflake” Divertor Configuration and Lithium Plasma-Facing Component Coatings in NSTX, Paper EXD/P3-32, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

31. S.A. Sabbagh, J.W. Berkery, J.M. Bialek, R.E. Bell, S.P. Gerhardt, et al., Resistive Wall Mode Stabilization and Plasma Rotation Damping Considerations for Maintaining High Beta Plasma Discharges in NSTX, Paper EXS/5-5 Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

32. S.P. Gerhardt, D.A. Gates, M.G. Bell, J.M. Canik, R.E. Bell, et al., Performance of Discharges with High Elongation and Beta in NSTX and Near Term Paths toward Steady State, Paper EXS/P2-08, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

33. R.J. Buttery, S.P. Gerhardt, R.J. La Haye, et al., The Impact of 3D Fields on Tearing Mode Stability of H-Modes, Paper EXS/P5-03, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

34. J.-K. Park, J.E. Menard, S.P. Gerhardt, M.J. Schaffer, et al. Robust Correction of 3D Error Fields in Tokamaks including ITER, Paper EXS/P5-12, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

35. E.D. Fredrickson, N. Gorelenkov, E. Belova, N. Crocker, S. Kubota, M Podesta`, S.P. Gerhardt, et al., Observation of Global Alfven Eigenmode Avalanche-like Events on the National Spherical Torus Experiment, Paper EXW/P7-06, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

36. J. Breslau, M.S. Chance, J. Chen, G. Fu, S.P. Gerhardt, N. Gorelenkov, S.C. Jardin, and J. Manickam, Onset and Saturation of a Non-Resonant Internal Mode in NSTX and Implications for AT Modes in ITER, Paper THS/P2-03, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

37. I. Bandyopadhyay, S.P. Gerhardt, S.C. Jardin, R.O. Sayer, Y. Nakamura, S. Miyamoto, G. Pautasso, M. Sugihara, and ASDEX Upgrade and NSTX Teams, TSC Modelling of Major Disruption and VDE Events in NSTX and ASDEX- Upgrade and Predictions for ITER, Paper ITR/P1-16, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

38. J.C. Wesley, P.C. De Vries, N.W. Eidietis, S.M. Flanagan, S.P Gerhardt, et al, Disruption, Halo Current and Rapid Shutdown Database Activities for ITER, Paper ITR/P1-26, Proceedings of the 23^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

39. D.J. Battaglia, C.-S. Chang, S.M. Kaye, S. Ku, R. Maingi, J.-W. Ahn, R.E. Bell, A. Diallo, S. Gerhardt, B.P. LeBlanc, J. Menard, V. Soukhanovskii, Dependence of the LH power threshold on the X-point radius, 38^th EPS Conference on Plasma Physics, paper P1.118, Strasbourg, France, 2011.

40. E. D. Fredrickson, N. A. Crocker, D. Darrow, N. N. Gorelenkov, S. Kubota, M. Podesta, A. Bortolon, S. Gerhardt, R. E. Bell, A. Diallo, B. LeBlanc, F. M. Levinton, H. Yuh, Internal Amplitude Measurements of CAE and GAE, 38^th EPS Conference on Plasma Physics, paper P2.119, Strasbourg, France, 2011.

41. J.W. Berkery, S.A. Sabbagh, R. Betti, R.E. Bell, A. Diallo, S.P. Gerhardt, B.P. LeBlanc, J. Manickam, and M. Podesta, Resistive wall mode kinetic stability advancements for refined comparison with experiments, 38^th EPS Conference on Plasma Physics, paper P1.078, Strasbourg, France, 2011.

42. R.J. La Haye, R.J. Buttery, S.P. Gerhardt, S.A. Sabbagh, and D.P. Brennan, Aspect Ratio Effects on Neoclassical Tearing Modes from Comparison Between DIII-D and NSTX, 38^th EPS Conference on Plasma Physics, paper P2.088, Strasbourg, France, 2011.

43. S.A. Sabbagh, J.W. Berkery, J.M. Bialek, S.P. Gerhardt, O. Katsuro-Hopkins, Y.S. Park, R.E. Bell, R. Betti, A. Diallo, D.A. Gates, B.P. LeBlanc, J.E. Menard, M. Podesta, K. Tritz, H. Yuh, Advances in resistive wall mode stabilization to maintain high beta, low internal inductance plasmas in NSTX, 38^th EPS Conference on Plasma Physics, paper P5.104, Strasbourg, France, 2011.

44. V. A. Soukhanovskii, J.-W. Ahn, D. Battaglia, R. E. Bell, A. Diallo, S. Gerhardt, et al., The snowflake divertor: a game-changer for magnetic fusion devices?, 38^th EPS Conference on Plasma Physics, paper P3.109, Strasbourg, France, 2011.

45. D. Mueller, E. Kolemen, N. Eidietis, S. Gerhardt, S.H. Hahn, J. Kim, Y.S. Park, S.A. Sabbagh, M.L. Walker and S.W. Yoon, Performance of and future improvements to plasma control in KSTAR, 39^th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

46. V. A. Soukhanovskii, R. E. Bell, A. Diallo, S. Gerhardt, et al., Divertor heat flux mitigation with impurity-seeded standard and snowflake divertors in NSTX, 39^th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

47. F. Scotti, V.A.Soukhanovskii, R.E. Bell, W. Guttenfelder, S. Kaye, S. Gerhardt, R. Kaita, B.P. Leblanc and the NSTX Team, Study of Intrinsic Impurities Core Transport in the National Spherical Torus Experiment, 39^th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

48. R. Raman, T.R. Jarboe, B.A. Nelson, D. Mueller, S.C. Jardin, C.E. Kessel, D.P. Stotler, T. Abrams, M.G. Bell, S.P. Gerhardt, S.M. Kaye, B.P. LeBlanc, J.E. Menard, M. Ono, E.B. Hooper, V.A. Soukhanovskii, and the NSTX Research Team, Progress on CHI Plasma Start-up and MGI Experiments on NSTX, 39^th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

49. E. T. Meier, V. A. Soukhanovskii, R. E. Bell, S. Gerhardt, R. Kaita, H. W. Kugel, B. P. LeBlanc, S. F. Paul, T. D. Rognlien, F. Scotti, M. V. Umansky, Modeling core impurity reduction via divertor gas injection in NSTX, 39^th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

50. S. P. Gerhardt, R. Bell, M. Bell, J. Berkery, A. Boozer, E. Fredrickson, E. Kolemen, B. P. LeBlanc, R. Maingi, J. Manickam, A. McLean, J. Menard, D. Mueller, R. Raman, S. Sabbagh, V. Soukhanovskii, and H. Yuh, Disruptions in the High-b Spherical Torus NSTX, Paper EX/9-3, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

51. S. M. Kaye, S. Gerhardt, R. E. Bell, A. Diallo, W. Guttenfelder, B. P. LeBlanc, and R. Maingi, The Dependence of H-mode Energy Confinement and Transport on Collisionality in NSTX, Paper EX/7-1, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

52. R. Maingi, D. P. Boyle, J. Canik, S. Kaye, T. Osborne, C. Skinner, M. Bell, R. Bell, A. Diallo, S. Gerhardt, et al., The Nearly Continuous Improvement of Discharge Characteristics and Edge Stability with Increasing Lithium Coatings in NSTX, Paper EX/11-2, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

53. R. Raman, D. Mueller, S. Jardin, T. Jarboe, B. Nelson, M. Bell, S. Gerhardt, E. Hooper, S. Kaye, C. Kessel, J. Menard, M. Ono, and V. Soukhanovskii, Non-inductive Plasma Start-up in NSTX Using Transient CHI, paper EX/P2-10, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

54. F. Scotti, V. A. Soukhanovskii, S. Kaye, S. Gerhardt, R. Andre, W. Guttenfelder, R. E. Bell, B. P. LeBlanc, and R. Kaita, Study of Carbon and Lithium Neoclassical Impurity Transport in ELM-Free H-Mode Discharges in NSTX, Paper EX/P3-34, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

55. E. Kolemen, M. Walker, D. Gates, D. Mueller, A. S. Welander, J. Menard, D. Humphreys, and S. Gerhardt, Vertical Stability of NSTX and NSTX-U, Paper EX/P4-28, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

56. V. Soukhanovskii, R. E. Bell, S. P. Gerhardt, S. Kaye, E. Kolemen, B. P. LeBlanc, E. Meier, J. E. Menard, A. G. McLean, S. F. Paul, T. D. Rognlien, D. D. Ryutov, F. Scotti, M. V. Umansky, D. Battaglia, A. Diallo, R. Kaita, R. Maingi, D. Mueller, M. Podesta, R. Raman, and A. L. Roquemore, Snowflake Divertor as Plasma-Material Interface for Future High Power Density Fusion Devices, Paper EX/P5-21, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

57. D. Battaglia, C. S. Chang, S. Kaye, S. H. Ku, R. Maingi, R. Bell, A. Diallo, S. Gerhardt, B. LeBlanc, and J. Menard, Dependence of the L-H Power Threshold on X-point Geometry, Paper EX/P5-28, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

58. M. Jaworski, T. Abrams, J. P. Allain, M. Bell, R. Bell, A. Diallo, T. Gray, S. Gerhardt, et al., Liquid Lithium Divertor Characteristics and Plasma-Material Interactions in NSTX High-Performance Plasmas, Paper EX/P5-31, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

59. R. Perkins, J. W. Ahn, R. Bell, A. Diallo, S. Gerhardt, T. Gray, D. Green, E. F. Jaeger, J. Hosea, M. Jaworski, B. LeBlanc, G. Kramer, A. McLean, R. Maingi, C. Phillips, P. Ryan, S. Sabbagh, G. Taylor, J. Wilson, and L. Roquemore, Fast Wave Power Flow along SOL Field Lines in NSTX, Paper EX/P5-40, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

60. E. Fredrickson, D. Darrow, N. Gorelenkov, G. Kramer, M. Podesta, S. Gerhardt, et al., Fast-ion Energy Loss during TAE Avalanches in the National Spherical Torus Experiment, Paper Ex/P6-05, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

61. J. Berkery, S. Sabbagh, R. Bell, R. Betti, J. Bialek, A. Diallo, D. Gates, S. Gerhardt, O. Katsuro-Hopkins, B. LeBlanc, J. Manickam, J. Menard, Y. S. Park, M. Podesta, and H. Yuh, Global Mode Control and Stabilization for Disruption Avoidance in High-b NSTX Plasmas, Paper EX/P8-07, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

62. J. Menard, T. Brown, J. Canik, J. Chrzanowski, L. Dudek, L. El-Guebaly, S. Gerhardt, et al., Progress on Developing the Spherical Tokamak for Fusion Applications, Paper FTP/3-4, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

63. M. Ono, M. Bell, M. Jaworski, R. Kaita, H. Kugel, J. W. Ahn, R. Bell, J. P. Allain, J. Canik, S. Ding, S. Gerhardt, et al., Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-relevant Liquid-lithium Based Divertor Development, Paper FTP/P1-14, Proceedings of the 24^nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

Conference Poster Presentations (incomplete):

1. D.T. Anderson, A.F. Almagri, F.S.B Anderson, S.P. Gerhardt, P.H. Probert, V. Sakaguchi, J. Shafi, J.L. Shohet, J.N. Talmadge, and S. Kitajima, Overview of the Initial HSX Experimental Program, APS-DPP, New Orleans, 1998.

2. F.S.B. Anderson, D.T. Anderson, A. F. Almagri, S.P. Gerhardt, P.H. Probert, V. Sakaguchi, J. Shafi, J.L. Shohet, J. N. Talmadge, and S. Kitajima, Fabrication and Initial Operation of the Helically Symmetric Experiment, APS-DPP, New Orleans, 1998.

3. S. P. Gerhardt, J.N. Talmadge, and J.L. Shohet, The Magnetic Field Structure outside the Separatrix in HSX, APS-DPP, New Orleans, 1998.

4. J.L. Shohet, G. Han, S.P. Gerhardt, T. Budimulia, and A.F. Almagri, Quantum Mechanical Non-Relativistic Spectra of Free-Free Bremsstrahlung from HSX, APS-DPP, New Orleans, 1998.

5. D.T. Anderson, A.F. Almagri, F.S.B. Anderson, J. Chen, S.P. Gerhardt, V. Sakaguchi, J. Shafi, and J.N. Talmadge, First Plasma Results and Initial Experimental Plan for HSX, APS-DPP, Seattle, 1999.

6. J.N. Talmadge, A. Almagri, D.T. Anderson, F.S.B Anderson, S.P. Gerhardt, V. Sakaguchi, J Shafi, R. J. Vernon, T.S. Bigelow, and K.M. Likin, Electron Cyclotron Heating at .5 T in HSX, APS-DPP, Seattle, 1999.

7. S.P. Gerhardt and J.N. Talmadge, Diffusion Coefficient and Electric Field Studies for HSX using Monte Carlo Methods, APS-DPP, Seattle, 1999.

8. B.E. Chapman, J.K. Anderson, T.M. Biewer, S. Castillo, P.K. Chattopadhyay, C.S. Chiang, D.J. Craig, G. Fiksel, P.W. Fontanna, C.B. Forest, S.P. Gerhardt, A.K. Hansen, D.J. Den Hartog, D. Holly, N.E. Lanier, S.C. Prager, J.S. Sarff, D.L. Brower, and Y. Jiang, Reduced Edge Instability and Improved Confinement in the MST RFP, APS-DPP, Seattle, 1999.

9. S.R. Castillo, J.K. Anderson, T.M. Biewer, B.E. Chapman, C.B. Forest, S. P. Gerhardt, D.J. Den Hartog, and N.E. Lanier, Measurement of the Z_eff Profile in MST, APS-DPP, Seattle, 1999.

10. B.E. Chapman, J.K. Anderson, T.M. Biewer, S. Castillo, P.K. Chattopadhyay, C.S. Chaing, D.J. Craig, N.A. Crocker, G Fiksel, P. W. Fontana, C.B. Forest, S.P. Gerhardt, A. K. Hansen, D.J. Den Hartog, D. Holly, N.E. Lanier, S.C. Prager, J. C. Reardon, J.S. Sarff, D.L. Brower, and Y. Jiang, Modifications to confinement and the current profile with auxiliary current drive in the MST RFP, APS-DPP, Quebec City, 2000.

11. D.T. Anderson, A.F. Almagri, F.S.B. Anderson, L. Feldner, S.P. Gerhardt, B. Harper, J.W. Radder, V. Sakaguchi, J. Shafii, J.N. Talmadge, R.J. Vernon, K Zhai, D. L. Brower, and C. Deng, ECH Operation of HSX at B=.5T, APS-DPP, Quebec City, 2000.

12. S. P. Gerhardt, J.N. Talmadge, Spectroscopic Diagnostics on the HSX Stellarator, APS-DPP, Quebec City, 2000.

13. J.W. Radder, D.T. Anderson, S.P. Gerhardt, A.F. Almagri, F.S.B. Anderson, J.N. Talmadge, D.L. Brower, and C. Deng, The Effects of Symmetry Breaking on Plasma Formation in the Helically Symmetric Experiment, APS-DPP, Long Beach, 2001.

14. A.F. Almagri, D.T. Anderson, C. Deng, S.P. Gerhardt, and J.N. Talmadge, Effects of Symmetry on Energy Content and Soft X-ray Profiles in the Helically Symmetric Experiment, APS-DPP, Long Beach, 2001.

15. S.P. Gerhardt, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, and J.N. Talmadge Initial Results from Biased Electrode Experiments in HSX, APS-DPP, Long Beach, 2001.

16. C. Deng, D.L. Brower, W.X. Ding, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, S.P. Gerhardt, P. Probert, J. Radder, and J.N. Talmadge, Measurements of Electron Density Profile and Fluctuations in HSX, APS-DPP, Long Beach, 2001.

17. S.P. Gerhardt, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, and J.N. Talmadge, Measurements of Plasma Flow in the HSX Stellarator using Mach Probes and UV Spectroscopy, 14^th Topical Conference on High Temperature Plasma Diagnostics, Madison, 2002.

18. J. Canik, D.T. Anderson, S.P. Gerhardt, and J.N. Talmadge, Measurements of Neutral Density and Fueling through H_a Emission in HSX, 14^th Topical Conference on High Temperature Plasma Diagnostics, Madison, 2002.

19. S.P. Gerhardt, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, J. Canik, and J.N. Talmadge, Plasma Flow Studies in the HSX Stellarator, APS-DPP, Orlando, 2002.

20. J.M. Canik, D.T. Anderson, S.P. Gerhardt, and J.N. Talmadge, Evidence of Reduced Direct Losses in HSX, APS-DPP, Orlando, 2002.

21. W.A. Guttenfelder, D.T. Anderson, J. Canik, S.P. Gerhardt, and J.N. Talmadge, Initial Turbulence Probe Measurements in HSX, APS-DPP, Orlando, 2002.

22. C. Deng, D.L. Brower, J.M. Canik, S.P. Gerhardt, D.T. Anderson, and F.S.B. Anderson, Electron Density Distribution in HSX, APS-DPP, Orlando, 2002.

23. A.F. Almagri, A.E. Abdou, D.T. Anderson, S.P. Gerhardt, and J.N. Talmadge, Soft X-ray Measurements in HSX the Helically Symmetric Stellarator, APS-DPP, Orlando, 2002.

24. A. Abdou, A.F. Almagri, D.T. Anderson, S.P. Gerhardt, J.N. Talmadge, and R. O'Connell, Hard X-ray Diagnostics in the HSX, APS-DPP, Orlando, 2002.

25. K.M. Likin, J.N. Talmadge, D.T. Anderson, F.S.B. Anderson, A.F. Almagri, S.P. Gerhardt, J.M. Canik, and C. Domier, ECE Diagnostic on the HSX Stellarator, APS-DPP, Orlando, 2002.

26. S.P. Gerhardt, A. Abdou, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, D. Brower, J. Canik, C. Deng, W.A. Guttenfelder, K. Likin, P.H. Probert, S. Oh, J. Tabora, V. Sakaguchi, J. Schmitt, J.N. Talmadge, and K. Zhai, Comparisons of ECH Plasmas with and without Symmetry in the Helically Symmetric Experiment, Workshop on Innovative Confinement Concepts, Seattle, 2003.

27. F.S.B. Anderson, A. Abdou, A. Almagri, D.T. Anderson, J. Canik, S.P. Gerhardt, W. Guttenfelder, K.M. Likin, S. Oh, J. Radder, V. Sakaguchi, J. Schmitt, J. Tabora, J.N. Talmadge, K. Zhai, D. Brower, and C. Deng, Experimental Plan and Recent Results from HSX, APS-DPP, Albuquerque, 2003.

28. K.M. Likin, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, S.P. Gerhardt, J.N. Talmadge, K. Zhai, and C. Deng, Electron Cyclotron Heating at B=0.5T in HSX, APS-DPP, Albuquerque, 2003.

29. S.P. Gerhardt, D.T. Anderson, J. Canik, W.A. Guttenfelder, J.N. Talmadge, and C. Deng, Characteristics of Electrode Biased Discharges in HSX, APS-DPP, Albuquerque, 2003.

30. J. Canik, D.T. Anderson, F.S.B Anderson, S.P. Gerhardt, J.N. Talmadge, C. Deng, and L. Owen, Neutral Density Modeling and Measurements in HSX, APS-DPP, Albuquerque, 2003.

31. W. A. Guttenfelder, D.T. Anderson, J. Canik, S.P. Gerhardt, J.N. Talmadge, and C. Lechte, Characteristics of Edge Turbulence in HSX, APS-DPP, Albuquerque, 2003.

32. C. Deng, D. L. Brower, J. Canik, S.P. Gerhardt, D.T. Anderson, and F.S.B. Anderson, Particle Transport and Density Fluctuations in HSX, APS-DPP, Albuquerque, 2003.

33. S.P. Gerhardt, D.T. Anderson, J.M. Canik, and the HSX Team, Measurements and Modeling of Plasma Flow Damping in the HSX Stellarator, Workshop on Innovative Confinement Concepts, Madison, 2004.

34. Y. Ren, S.P. Gerhardt, H. Ji, R. Kulsrud, and M. Yamada, Study of the Fine Structures and Fluctuations in the Current Sheet in MRX, APS-DPP, Savannah, 2004.

35. A.J. Carver, M. Yamada, H. Ji, S.P. Gerhardt, A. Kuritsyn, and Y. Ren, Study of Boundary Effects on the Reconnection Rate in MRX, APS-DPP, Savannah, 2004.

36. M. Yamada, H. Ji, R. Kulsrud, S.P. Gerhardt, A. Kuritsyn, Y. Ren, and Y. Wang, Study of Global and Local Physics of Magnetic Reconnection on MRX, APS-DPP, Savannah, 2004.

37. A. Kuritsyn, S.P. Gerhardt, H. Ji, Y. Ren, and M. Yamada, Study of the Ion Dynamics in the MRX Current Sheet, APS-DPP, Savannah, 2004.

38. S.P. Gerhardt, M. Yamada, H. Ji, E. Belova, D. Mikkelsen, S. Zweben, R.C. Davidson, and R. Kaita, FRC Studies via Spheromak Merging in the Magnetic Reconnection Experiment, APS-DPP, Savannah, 2004.

39. J.N. Talmadge, A. Abdou, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, D.L. Brower, J.M. Canik, C. Deng, S.P. Gerhardt, W. Guttenfelder, C.H. Lechte, K.M. Likin, J. Lu, S. Oh, J. Radder, V. Sakaguchi, J. Schmitt, and Z. Zhai, Overview of the HSX Experimental Program, APS-DPP, Savannah, 2004.

40. J.M. Canik, D.T. Anderson, C. Deng, S.P. Gerhardt, J.N. Talmadge, and K. Zhai, Neoclassical Transport in HSX, APS-DPP, Savannah, 2004.

41. C. Deng, D. Brower, D. Spong, A. Abdou, A.F. Almagri, D.T. Anderson, F.S.B. Anderson, S.P. Gerhardt, K.M. Likin, S. Oh, V. Sakaguchi, J.N. Talmadge, and K. Zhai, Evidence for Alfvenic Fluctuations in the Quasi-Helically Symmetric HSX Plasmas, APS-DPP, Savannah, 2004.

42. J. Schmitt, S.P. Gerhardt, D.T. Anderson, and J.N. Talmadge, Calculation of Neoclassical Viscous Damping Due to Magnetic Islands in the HSX Stellarator, APS-DPP, Savannah, 2004.

43. D.L. Brower, C. Deng, D.A. Spong, A. Abdou, A.F. Almagri, D. T. Anderson, F.S.B. Anderson, S.P. Gerhardt, W. Guttenfelder, K. Likin, S. Oh, V. Sakaguchi, J.N. Talmadge, and K. Zhai, Observation of Fast-Electron-Driven Alfenic Modes in the HSX Stellarator, EPS, 2005.

44. D.L. Brower, C. Deng, D.A. Spong, A. Abdou, A.F. Almagri, D. T. Anderson, F.S.B. Anderson, S.P. Gerhardt, W. Guttenfelder, K. Likin, S. Oh, V. Sakaguchi, J.N. Talmadge, and K. Zhai, Observation of Fast-Electron-Driven Alfvenic Modes in the HSX Stellarator, Transport Task Force, 2005.

42. S.P. Gerhardt, M. Inomoto, M. Yamada, H. Ji, A. J. Carver, A. Kuritsyn, B. McGeehan, and Y. Ren, Stability Studies of Compact Toroid Plasmas in MRX, APS-DPP, Denver, 2005.

43. J. Schmitt, J.N. Talmadge, D.T. Anderson, and S.P. Gerhardt, Increased Parallel Viscous Damping Near Magnetic Islands in HSX, APS-DPP, Denver, 2005.

44. S.P. Gerhardt, M. Yamada, H. Ji, and M. Inomoto, Equilibrium Reconstruction Techniques Applied to compact Toroid Plasmas in MRX, APS-DPP, Denver, 2005.

45. M. Yamada, H. Ji, S.P. Gerhardt, M. Inomoto, R. Kulsrud, A. Kuritsyn, and Y. Ren, Study of Two-fluid Effects during Magnetic Reconnection in a Laboratory Experiment, APS-DPP, Denver, 2005.

46. M. Inomoto, S.P. Gerhardt, M. Yamada, H. Ji, B. McGeehan, A. Kuritsyn, Y. Ren, and E. Belova, Reconnection and Ion Acceleration Processes during Counter Helicity Merging of Spheromaks in the MRX, APS-DPP, Denver, 2005.

47. E.V. Belova, R.C. Davidson, H. Ji, M. Yamada, S.P. Gerhardt, and M. Inomoto, Three-Dimensional Hall-MHD Simulation of Counter-Helicity Spheromak Merging and FRC Formation, APS-DPP, Denver, 2005.

48. Y. Ren, M. Yamada, S.P. Gerhardt, H. Ji, R. Kulsrud, A. Kuritsyn, and M. Inomoto, Experimental Studies of the Hall Effect and Fluctuation in MRX, APS-DPP, Denver, 2005

49. A.J. Carver, M. Yamada, H. Ji, S.P. Gerhardt, A. Kuritsyn, Y. Ren, and M. Inomoto, Spectroscopic Studies of Merging Spheromak Plasmas in the Magnetic Reconnection Experiment, APS-DPP, Denver, 2005.

50. H. Ji, M. Yamada, S.P. Gerhardt, E. Belova, M. Inomoto, and Y. Ono, Recent Advances in the SPIRIT Concept, ICC 2006, Austin, Texas.

51. H. Ji, A. Kuritsyn, M. Yamada, S.P. Gerhardt, and Y. Ren, Effects of Global Boundary and Local Collisionality on Magnetic Reconnection in MRX, APS-DPP, Philadelphia, 2006.

52. M. Yamada, Y. Ren, H. Ji, S.P. Gerhardt, M. Inomoto, R. Kulsrud, S. Dorfman, and Y. Wang, Experimental Study of Two-fluid Effects on Magnetic Reconnection, APS-DPP, Philadelphia, 2006.

53. Y. Ren, M. Yamada, H. Ji, S.P. Gerhardt, A. Kuritsyn, R. Kulsrud, and H. Torreblanca, The Hall Effect and Magnetic Fluctuations during Fast Reconnection in MRX, APS-DPP, Philadelphia, 2006.

54. S. Dorfman, H. Jim M. Yamada, Y. Ren, and S.P. Gerhardt, Active Perturbation of the Reconnecting Current Sheet in MRX, APS-DPP, Philadelphia, 2006.

55. H. Torreblanca, S.P. Gerhardt, M. Yamada, H. Ji, and Y. Ren, Mach Probe Measurements in the Context of the Hall Effect in MRX, APS-DPP, Philadelphia, 2006.

56. E.V. Belova, R.C. Davidson, S.P. Gerhardt, and C. Cothran, Two-fluid Simulations of Counter-Helicity Spheromak Merging and Oblate FRC stability in MRX and SSX Experiments, APS-DPP, Philadelphia, 2006.

57. S.P. Gerhardt, M. Inomoto, E.V. Belova, M. Yamada, H. Ji, Y. Ren, S. Dorfan, E. Martin, Studies of Equilibrium and Stability of Oblate FRCs in the Magnetic Reconnection Experiment, APS-DPP, Philadelphia, 2006.

58. E. Martin, S.P. Gerhardt, M. Yamada, H. Ji, T. Ren S. Dorfman, and H. Toreblanca, Plans and Progress of Electrode Biased Plasmas in the Magnetic Reconnection Experiment, APS-DPP, Philadelphia, 2006.

59. S. P. Gerhardt, E.V. Belova, M. Yamada, H. Ji, Y. Ren, B. McGeehan, C. Jacobson, and M. Inomoto, Studies of Inductively Sustained Compact Toroids in MRX, APS-DPP, Orlando, 2007.

60. M. Yamada, Y. Ren, H. Ji, S.P Gerhardt, B. McGeehan, C. Jacobson, J. Baumgaertel, R. Kulsrud, and S. Dorfman, Identification of a Two-scale Diffusion Layer During Magnetic Reconnection in a Laboratory Plasma, APS-DPP, Orlando, 2007.

61. B. McGeehan, M. Yamada, H. Ji, S.P. Gerhardt, C. Jacobson, J. Baumgaertel, and S. Dorfman, Investigation of the 3-D profile of the reconnection layer with and without a guide field, APS-DPP, Orlando, 2007.

62. C. Jacobson, M. Yamada, H. Ji, S.P. Gerhardt, B. McGeehan, Study of the Effects of Guide Field on Reconnection in MRX, APS-DPP, Orlando, 2007.

63. J.A. Baumgaertel, S. Dorfman, B. McGeehan S.P. Gerhardt, H. Ji, and M. Yamada, Active Perturbations in the Outflow Region of the MRX Current Sheet, APS-DPP, Orlando, 2007.

64. D.A. Gates, S.P. Gerhardt, H. Kugel, J.E. Menard, and S.A. Sabbagh, Advanced Scenario Development on NSTX, APS-DPP, Dallas, 2008.

65. J. Canik, R. Maingi, T. Evans, T. Osborne, S.P. Gerhardt, J.K. Park, S. Sabbagh, Z. Unterberg, ELM Destabilization by Magnetic Perturbations at NSTX, APS-DPP, Dallas, 2008.

66. S.A. Sabbagh, J.W. Berkery, J.M. Bialek, R.E. Bell, D.A. Gates, S.P. Gerhardt, B. LeBlanc, J. Manickam, J.E. Menard, R. Betti, and B. Hu, Global Mode Stability and Active Control in NSTX, APS-DPP, Dallas, 2008.

67. R.W. Hawryluk, S.A. Sabbagh, R. Maingi, J. Bialek, J.M. Canik, S.P. Gerhardt, J.E. Menard, and J.-K. Park, NSTX EML and RWM Control Experiments and Modeling for ITER, APS-DPP, 2008.

68. H.W. Kugel, D. Mansfield, M.G. Bell, R. Bell, D. Gates, S.P. Gerhardt, R. Kaita, J. Kallman, S. Kaye. B. LeBlanc, R. Majeski, D. Mueller, S. Paul, L. Roquemore, P.W. Ross, H. Schneider, H. Skinner, J. Timberlake, S. Sabbagh, V. Soukhanovskii, W.R. Wampler, R. Maingi, R. Wilgen, J.P. Allain, R. Raman, NSTX Experiments with Lithium Plasma-Facing Components -- Recent Results and Future Plans, APS-DPP, Dallas, 2008.

69. P. W. Ross, R.E. Bell, D.A. Gates, S.P. Gerhardt, S.M. Kaye, B.P. LeBlanc, S.S. Medley, R.B. White, M. Podesta, Ion Power Balance in NSTX, APS-DPP, Dallas, 2008.

70. S.P. Gerhardt, R.J. La Haye, E.J. Strait, R.J. Buttery, D. Brennan, E. Fredrickson, D. Gates, M. Maraschek, J.E. Menard, S.A. Sabbagh, Overview of Neoclassical Tearing Mode Studies in NSTX, APS-DBB, Dallas, 2008.

71. J. Kallman, R. Kaita, H. Kugel, R. Ellis, S.P. Gerhardt, M.A. Jaworski, A.L. Roquemore, and S. Zweben, Edge and Scrape-off Layer Diagnostics for the NSTX Liquid Lithium Divertor, APS-DPP, Dallas, 2008.

72. S. Paul, M.G. Bell, S.P. Gerhardt, H.W. Kugel, J. Kallman, R. Kaita, J.A. Robinson, Dependence of impurity accumulation on I_P and the outer gap in the presence of lithium deposition in NSTX, APS-DPP, Atlanta, 2009.

73. J. Kallman, R. Kaita, H. Kugel, E. Kolemen, M.A. Jaworski, J.W. Ahn, D. Gates, S. Gerhardt, R. Maingi, J. Robinson, A.L. Roquemore, V. Soukhanovskii, Development of Operational Scenarios and Edge Diagnostics for the NSTX Liquid Lithium Divertor, APS-DPP, Atlanta, 2009

74. J.M. Canik, R. Maingi, A.C. Sontag, S.P. Gerhardt, S. Kaye, R.E. Bell, D. Gates, R. Goldston, B.P. LeBlanc, J. Menard, J.-K. Park, T. Evans, T. Osborne, S. Sabbagh, E.A. Unterberg, NSTX ELM Pacing and L-H Threshold Experiments for ITER, APS-DPP, Atlanta, 2009.

75. Hiro Takahashi, Eric Fredrickson, Josh Kallman, Stefan Gerhardt, Robert Kaita, Dennis Mansfield, Stuart Zweben, Rajesh Maingi , Study of Thermo-electrically Driven Scrape-Off-Layer Current (SOLC) in NSTX Tokamak, APS-DPP, Atlanta, 2009.

76. S.C. Jardin, J. Breslau, J. Chen, S. Gerhardt, N. Ferraro, X. Luo, K. Jansen, M. Shephard, Initial application of the M3D-C¹ code to the study of non-ideal modes in NSTX, APS-DPP, Atlanta, 2009.

77. M.G. Bell , H. Kugel , D. Mansfield , R. Kaita , S. Gerhardt , S. Paul , R.E. Bell, R. Maingi  J. Canik, Plasma Response to Lithium-Coated Plasma-Facing Components in NSTX, APS-DPP, Atlanta, 2009.

78. David Gates , S.P. Gerhardt , E. Kolemen, Advanced Scenario and Plasma Control Development on NSTX, APS-DPP, Atlanta, 2009.

79. Luis F. Delgado-Aparicio, K. Tritz, M. Finkenthal  D. Stutman , S.A. Sabbagh, J. Berkery, S. Gerhardt, R. Bell, B. LeBlanc, J. Manickam, J. Menard, L. Roquemore, SXR measurements of Resistive Wall Mode behavior in NSTX, APS-DPP, Atlanta, 2009.

80. Stefan Gerhardt, Jon Menard, Jong-Kyu Park, Ron Bell, Dave Gates, Benoit LeBlanc, Steve Sabbagh, Howard Yuh, Error Field Physics and Correction at High Beta in NSTX, APS-DPP, Atlanta, 2009.

81. J.K. Lepson, P. Beiersdorfer, M. Bitter, L. Roquemore, G. Zimmer, S. Gerhardt, J. Kallman, R. Kaita, Identification and time evolution of impurities in NSTX plasmas, APS-DPP, Atlanta, 2009.

82. H.W. Kugel, M. Viola, R. Ellis, M. Bell, S. Gerhardt, R. Kaita, J. Kallman, R. Majeski, D. Mansfield, A.L. Roquemore, H. Schneider, J. Timberlake, L. Zakharov, R.E. Nygren,J.P. Allain, R. Maingi, V. Soukhanovskii, Status of National Spherical Torus Experiment Liquid Lithium Divertor, APS-DPP, Atlanta, 2009.

83. Frederick Kelly, Eric Fredrickson, Stefan Gerhardt, Rajesh Maingi, Jon Menard, Steve Sabbagh, Hiro Takahashi, Investigation of ELM magnetic precursors in NSTX discharges with and without lithium wall coatings, APS-DPP, Atlanta, 2009.

84. J. Kallman, R. Kaita, H. Kugel, E. Kolemen, M.A. Jaworski, J.W. Ahn, D. Gates, S. Gerhardt, R. Maingi, J. Robinson, A.L. Roquemore, V. Soukhanovskii, Development of Operational Scenarios and Edge Diagnostics for the NSTX Liquid Lithium Divertor, APS-DPP, Atlanta, 2009.

85. Jong-Kyu Park, Jonathan Menard, Stefan Gerhardt, Allen Boozer, Steve Sabbagh, Michael Schaffer, Stephen Wolfe, Study of Error Field Physics in Tokamaks and Implications for ITER, APS-DPP, Atlanta, 2009.

86. Oksana Katsuro-Hopkins, S.A. Sabbagh, J.M. Bialek, S.P. Gerhardt, Design of a Linear-Quadratic-Gaussian controller for resistive wall mode stabilization in NSTX, APS-DPP, Atlanta, 2009.

87. S.A. Sabbagh, J.W. Berkery, J.M. Bialek, L. Delgado-Aparicio, K. Tritz, R.E. Bell, S.P. Gerhardt, B. LeBlanc, Search for Multiple Resistive Wall Modes at High Normalized Beta in NSTX, APS-DPP, Atlanta, 2009.

88. R.J. Buttery, C.D. Challis, R.J. La Haye, S.P. Gerhardt, Sensitivity of Tearing Mode Beta Limits to Rotation and Current Profile, APS-DPP, Atlanta, 2009.

89. A.C. Sontag, J.M. Canik, R. Maingi, D.A. Gates, S.P. Gerhardt, V.A. Soukhanovskii, Discharge Evolution Control via 3D Field ELM Pacing in NSTX, APS-DPP, Atlanta, 2009.

90. S. Gerhardt , D. Gates  J. Menard  M. Bell  R. Bell  J. Canik  S. Kaye  H. Kugel  E. Fredrickson  B. LeBlanc  R. Maingi  S. Sabbagh  V. Soukhanovskii  K. Tritz  H. Yuh, Progress in the Development of Advanced Spherical Torus, APS DPP, Chicago, 2010.

91. James Bialek, S.A. Sabbagh, L. Delgado-Aparicio, S.P. Gerhardt , Multi-mode RWM analysis of NSTX high beta plasmas, APS DPP, Chicago, 2010.

92. H.W. Kugel , M.G. Bell , R. Bell , S. Gerhardt , M.A. Jaworski,  R. Kaita,  J. Kallman , B. Leblanc,  D. Mansfield,  D. Mueller,  S. Paul , A.L. Roquemore,  F. Scotti,  C.H. Skinner , J. Timberlake , L.E. Zakharov , J.P. Allain , C. Taylor,  B. Heim, R. Maingi , R Nygren R. Raman , S. Sabbagh , V. Soukhanovskii , Overview of NSTX Liquid Lithium Divertor Performance and Divertor Upgrade Plans, APS DPP, Chicago, 2010.

93. R.J. La Haye , R.J. Buttery,  S.P. Gerhardt, S.A. Sabbagh, D.P. Brennan , Comparison of Aspect Ratio Effects on Neoclassical Tearing Modes Between DIII-D and NSTX, APS DPP, Chicago, 2010.

94. Stephen Jardin,  Robert Andre, Jin Chen, Stefan Gerhardt, Christiane Ludescher, Doug McCune, Royce Sayer, Free Boundary Modeling of NSTX Plasmas, APS DPP, Chicago, 2010

95. F. Scotti, VA. Soukhanovskii, R.E. Bell, S. Gerhardt, M. Jaworski, R. Kaita, J. Kallman, H.W. Kugel, B.P. Leblanc, R. Maqueda, S.F. Paul, M. Podesta, A.L. Roquemore, D.J. Battaglia, R. Raman, Core impurity reduction using divertor D₂ injection in lithium-conditioned H-mode discharges in NSTX, APS DPP, Chicago, 2010

96. R. Maingi, J. Canik, R. Bell, S. Gerhardt, S. Kaye, B. LeBlanc, T. Osborne, Triggered confinement and pedestal temperature enhancement in NSTX H-mode discharges, APS DPP, Chicago, 2010

97. H. Takahashi, E. Fredrickson, S. Gerhardt, M. Jaworski, R. Kaita, J. Kallman, D. Mansfield, S. Zweben, S. Sabbagh, R. Maingi, I. Joseph, Response of Thermo-electrically Driven Scrape-Off-Layer Current (SOLC) during ELMs to Discharge Manipulation in NSTX Tokamak, APS DPP, Chicago, 2010

98. J.A. Breslau , M.S. Chance,  J. Chen , G.-Y. Fu , S. Gerhardt , N. Gorelenkov , S.C. Jardin , J. Manickam, Multiphysics Analysis of a Non-Resonant Internal Mode in NSTX, APS DPP, Chicago, 2010

99. Egemen Kolemen, D.A. Gates, S. Gerhardt, R. Kaita, J. Kallman, H. Kugel, D. Mueller, V. Soukhanovskii , Results of the NSTX Control Experiments, APS DPP, Chicago, 2010

100. M.G. Bell , S.P. Gerhardt , D. Mueller , N. Pomphrey, A.H. Boozer, Measuring Error Fields in ITER Before Its First Plasma, APS DPP, Chicago, 2010

101. A. Sontag , J. Canik , R. Maingi, J. Manickam , R. Bell , S. Gerhardt , B. LeBlanc, S. Kubota, T. Osborne , P. Snyder, K. Tritz, Edge Stability of Small-ELM Regimes in NSTX, APS DPP, Chicago, 2010

102. J.M. Canik , J.-W. Ahn , R. Maingi, R.E. Bell , A. Diallo , S.P. Gerhardt , B.P. LeBlanc , J.E. Menard , J.-K. Park , M. Podesta, S.A. Sabbagh, Effect of 3-D magnetic perturbations on pedestal structure and transport in NSTX, APS DPP, Salt Lake City, 2011

103. Janardhan Manickam, Stefan Gerhardt, Allen Boozer, Onset conditions for disruptions during VDEs, APS DPP, Salt Lake City, 2011

104. Hironori Takahashi, Eric Fredrickson, Stefan Gerhardt, Stewart Zweben, Amplifying and Transforming of External Error Field by Scrape-Off-Layer Current (SOLC) in Tokamaks, APS DPP, Salt Lake City, 2011

105. Stanley Kaye, Stefan Gerhardt, Rajesh Maingi, Ron Bell, Ahmed Diallo, Benoit LeBlanc, Effect of collisionality on energy transport in NSTX, APS DPP, Salt Lake City, 2011

106. J. Bialek,  J.W. Berkery,  S.A. Sabbagh, R. Betti,  R.E. Bell , A. Diallo , S.P. Gerhardt , B.P. LeBlanc  J. Manickam, M. Podesta, Validation of RWM Kinetic Stability Model and Physics Implications in NSTX, APS DPP, Salt Lake City, 2011

107. F. Scotti, .A. Soukhanovskii, S. Kaye, R. Andre, S. Gerhardt, R.E. Bell, A. Diallo, B.P. Leblanc, M. Podesta, S.A. Sabbagh, .W. Kugel, R. Kaita, M.G. Bell, Study of C and Li neoclassical transport in NSTX Li-conditioned ELM-free H-mode discharges, APS DPP, Salt Lake City, 2011

108. S.S. Medley, G.J. Kramer, R.E. Bell, E. Belova, E.D. Fredrickson, S.P. Gerhardt, B.P. LeBlanc, M. Podesta, Y. Ren , A.L. Roquemore, N.A. Crocker, Transient energetic charge exchange flux enhancement observed in NSTX neutral-beam-heated H-mode discharges, APS DPP, Salt Lake City, 2011

109. V.A. Soukhanovskii, S.P. Gerhardt , R. Kaita  E. Kolemen , H.W. Kugel , J.E. Menard, R. Maingi  A. McLean, Snowflake divertor configuration studies for NSTX-Upgrade, APS DPP, Salt Lake City, 2011

110. R. Raman , T.R. Jarboe , B.A. Nelson, D. Mueller , S.P. Gerhardt,  H.W. Kugel,  G. Taylor, Progress on CHI and MGI Experiments on NSTX, APS DPP, Salt Lake City, 2011

111. H.W. Kugel , M.G. Bell , R. Bell , A. Diallo,  S. Gerhardt , M. Jaworski , R. Kaita,  J. Kallman,  B. Leblanc , D. Mansfield , D. Mueller , S. Paul,  A.L. Roquemore , F. Scotti , C.H. Skinner , J. Timberlake, L. Zakharov, J.P. Allain,  B. Heim,  C. Taylor, A. McLean,  R. Maingi, R. Raman, S. Sabbagh, V. Soukhanovskii,  Comparison of Diverted Plasmas Incident on Liquid Lithium and Lithiated Molybdenum, and Graphite Surfaces, APS DPP, Salt Lake City, 2011

112. J.W. Berkery,  S.A. Sabbagh , J.M. Bialek,  O. Katsuro-Hopkins, R.E. Bell, S.P. Gerhardt,  B.P. LeBlanc, K. Tritz, RWM Stabilization to Sustain High Normalized Beta at Low Internal Inductance in NSTX, APS DPP, Salt Lake City, 2011

113. Egemen Kolemen, D.A. Gates , S.P. Gerhardt , D.A. Humphreys , D. Mueller , V. Soukhanovskii  , M.L. Walker, Control Development for NSTX and the Effects of Strong Shaping, APS DPP, Salt Lake City, 2011

114. R.J. Perkins, R.E. Bell, A. Diallo, S. Gerhardt, J.C. Hosea, M. Jaworski, B.P. LeBlanc, G.J. Kramer, C.K. Phillips, L. Roquemore, G. Taylor, J.R. Wilson, S. Zweben, J.-W. Ahn, T.K. Gray, D.L. Green, A. McLean, R. Maingi, P.M. Ryan,. Wilgen, K. Tritz, HHFW Edge Heating Properties for H-mode Plasmas in NSTX, APS DPP, Salt Lake City, 2011

115. V.A. Soukhanovskii, S.P. Gerhardt , R. Kaita , E. Kolemen , H.W. Kugel , J.E. Menard, R. Maingi , A. McLean , Snowflake divertor configuration studies for NSTX-Upgrade, APS DPP, Salt Lake City, 2011

116. J.W. Berkery , S.A. Sabbagh , J.M. Bialek , O. Katsuro-Hopkins, R.E. Bell , S.P. Gerhardt , B.P. LeBlanc, K. Tritz, RWM Stabilization to Sustain High Normalized Beta at Low Internal Inductance in NSTX, APS DPP, Salt Lake City, 2011

117. R.J. La Haye, R.J. Buttery, S.P. Gerhardt, S.A. Sabbagh, Rotation in the Plasma Flow Frame of Marginal Neoclassical Tearing Mode Islands in DIII-D and NSTX, APS DPP, Salt Lake City, 2011

118. R. Kaita, H. Kugel , M.G. Bell , R. Bell , M. Diallo , S. Gerhardt , M. Jaworski , J. Kallman , S. Kaye , B. LeBlanc , D. Mansfield , J. Menard , D. Mueller , S. Paul , A.L. Roquemore , F. Scotti , C.H. Skinner , L. Zakharov, J.P. Allain , A. McLean , R. Maingi , R. Nygren, R. Raman , S. Sabbagh  ,V. Soukhanovskii, Overview of NSTX Liquid Lithium Divertor Performance and Divertor Upgrade Plans, APS DPP, Salt Lake City, 2011.

119. E. T. Meier, V. A. Soukhanovskii, R. E. Bell, S. Gerhardt, R. Kaita, H. W. Kugel, B. P. LeBlanc, S. F. Paul, T. D. Rognlien, F. Scotti, M. V. Umansky, Modeling core impurity reduction via divertor gas injection in NSTX, 39^th EPS Conference on Plasma Physics, paper P1.002, Stockholm, Sweden, 2012.

120. F. Scotti, V.A. Soukhanovskii, S. Kaye, S. Gerhardt, R. Andre, W. Guttenfelder, R.E. Bell, B.P. Leblanc, R. Kaita and the NSTX Team, Study of Intrinsic Impurities Core Transport in the National Spherical Torus Experiment, 39^th EPS Conference on Plasma Physics, paper P4.031, Stockholm, Sweden, 2012.

121. R. Raman, T.R. Jarboe, B.A. Nelson, D. Mueller, S.C. Jardin, D.P. Stotler, T. Abrams, M.G. Bell, S.P. Gerhardt, C.E. Kessel, S.M. Kaye, B.P. LeBlanc, J.E. Menard, M. Ono, E.B. Hooper, V.A. Soukhanovskii, and the NSTX Research Team, Progress on CHI Plasma Start-up and MGI Experiments on NSTX, 39^th EPS Conference on Plasma Physics, paper P2.008, Stockholm, Sweden, 2012.

122. D. Mueller, E. Kolemen, N. Eidietis, S. Gerhardt, S.H. Hahn, J. Kim, Y.S. Park, S.A. Sabbagh, M.L. Walker and S.W. Yoon, Performance of and future improvements to plasma control in KSTAR, 39^th EPS Conference on Plasma Physics, paper P5.027, Stockholm, Sweden, 2012.

123. E. D. Fredrickson, N. A. Crocker, D. Darrow, N. N. Gorelenkov, G. Kramer, S. Kubota, M. Podesta, A. Bortolon, S. Gerhardt, R. E. Bell, A. Diallo, B. LeBlanc, F. M. Levinton, R. White, H. Yuh, Fast-ion energy loss during TAE avalanches in the National Spherical Torus Experiment, 39^th EPS Conference on Plasma Physics, paper P5.0050, Stockholm, Sweden, 2012.

124. J.W. Berkery, S.A. Sabbagh, J.M. Bialek, Y.S. Park, S.P. Gerhardt, R.E. Bell, B.P. LeBlanc,  Resistive Wall Mode Physics and Control to Sustain High Normalized Beta in NSTX, APS DPP, Providence, 2012

125. R.J. Perkins, R.E. Bell, A. Diallo, S. Gerhardt, J.C. Hosea, M.A. Jaworski, B.P. LeBlanc, G.J. Kramer, C.K. Phillips, L. Roquemore, G. Taylor J.R. Wilson, J.-W. Ahn, T.K. Gray, D.L. Green, A. McLean, R. Maingi, P.M. Ryan, E.F. Jaeger, S. Sabbagh, Fast wave power flow along SOL field lines in NSTX, APS DPP, Providence, 2012

126. J. Bialek, J. Berkery, S. Sabbagh,  O. Katsuro-Hopkins, R. Betti, R. Bell, S. Gerhardt, B. LeBlanc , Y. Liu, Kinetic RWM Stabilization Physics and RWM State-Space Control in NSTX High Beta Plasmas, APS DPP, Providence, 2012

127. Joel Hosea, R.E. Bell, A. Diallo, S. Gerhardt, M.A. Jaworski, G.J. Kramer, B.P. LeBlanc, R.J. Perkins, C.K. Phillips, L. Roquemore, G. Taylor, J.R. Wilson, J-W. Ahn, T.K. Gray, R. Maingi, A. McLean, P.M. Ryan, S. Sabbagh, and the NSTX Team, SOL Properties of HHFW Electron Heating Generated H-modes in NSTX, APS DPP, Providence, 2012

128. E.T. Meier, V.A. Soukhanovskii, A.G. McLean, T.D. Rognlien, D.D. Ryutov, R.E. Bell, A. Diallo, S. Gerhardt, R. Kaita, B.P. LeBlanc, J.E. Menard, M. Podesta, F. Scotti, UEDGE modeling of NSTX and NSTX-U snowflake divertor configurations, APS DPP, Providence, 2012

129. C.K. Phillips, N. Bertelli, R.V. Budny, S. Gerhardt, J.C. Hosea, B.P. LeBlanc, J.E. Menard, G. Taylor, E.J. Valeo, J.R. Wilson, E.F. Jaeger, P.T. Bonoli, J.C. Wright, R.W. Harvey, L.A. Berry, D.L. Green , Initial predictive studies of HHFW heating in the NSTX-U device, APS DPP, Providence, 2012

130. J.M. Canik, R. Maingi, S.P. Gerhardt, M.A. Jaworski, J.E. Menard, D.P. Stotler, E. Meier, V.A. Soukhanovskii, Physics design of a cryo-pumping system for NSTX-U, APS DPP, Providence, 2012

131. V.A. Soukhanovskii, A.G. McLean, E.T. Meier, T.D. Rognlein, D.D. Ryutov, R.E. Bell, A. 132. Diallo, S.P. Gerhardt, R. Kaita, E. Kolemen, B.P. LeBlanc, J.E. Menard, M. Podesta, F. Scotti, PPPL, NSTX-U TEAM, Divertor scenario development for NSTX Upgrade, APS DPP, Providence, 2012

133. M. Podesta, N.N. Gorelenkov, E.D. Fredrickson, S.P. Gerhardt, G.J. Kramer, Initial predictions of linear TAE stability in NSTX-U, APS DPP, Providence, 2012

134. S.P. Gerhardt, J. Breslau, E. Fredrickson, S. Jardin, R. Kaita, J. Manickam, J. Menard, S. Sabbagh, Columbia University, F. Scotti, H. Takahashi, PPPL, A.H. Boozer, Characterization of Disruption Halo Currents in NSTX, APS DPP, Providence, 2012.

135. Hironori Takahashi, Eric Fredrickson , Stefan Gerhardt , Error Field in Ideal Magnetically Symmetric Tokamaks Generated through Asymmetric Shadows Cast by Neutral Beams on Divertor Floor, APS DPP, Providence, 2012.

136. J. Menard, J. Bialek, J. Canik, J. Chrzanowski, D. Gates, S. Gerhardt, W. Guttenfelder, S. Kaye, E. Kolemen, R. Maingi, M. Mardenfeld, D. Mueller, C. Neumeyer, M. Ono, E. Perry, S. Raftopoulos, R. Ramakrishnan, R. Raman, Y. Ren, S. Sabbagh, V. Soukhanovskii, T. Stevenson, R. Strykowsky, P. Titus, K. Tresemer, H. Zhang, Y. Zhai, A. Zolfaghari, NSTX Accomplishments and NSTX Upgrade Research Plans in Support of Fusion Next-Steps, SOFE-2013, San Francisco, 2013.

137. J. Menard, T. Brown, J. Canik, L. El-Guebaly, S. Gerhardt, A. Jaber, S. Kaye, E. Meier, L. Mynsberge, C. Neumeyer, M. Ono, R. Raman, S. Sabbagh, V. Soukhanovskii, P. Titus, G. Voss, R. Woolley, A. Zolfaghari, ST-FNSF Mission and Performance Dependence on Device Size, SOFE-2013, San Francisco, 2013.

138. N. D. Atnafu, M. Denault, M. Smith, L. Dudek, S. Gerhardt, G. Labik, T. Stevenson, P. Titus, W. Blanchard, NSTX-U Vacuum Vessel Design Modification, SOFE-2013, San Francisco, 2013.

139. K. Tresemer, S. Gerhardt, A. Brooks, A. Jariwala, R. Raman, Modification of NSTX-U Row 1 Outboard and Inboard Divertor Tiles for the Protection of the PF-1C Coils, SOFE-2013, San Francisco, 2013.

· 2009-Present: Research Physicist, National Spherical Torus Experiment (NSTX)

· Spring 2007-2009: Staff Research Physicist, National Spherical Torus Experiment (NSTX)

· Fall 2006-Fall 2007: Staff Research Physicist, Magnetic Reconnection Experiment, Princeton Plasma Physics Laboratory (PPPL)

· Summer 2004-Fall 2006: Associate Research Physicist, Magnetic Reconnection Experiment, Princeton Plasma Physics Laboratory

2. Studies of Bias Induced Plasma Flows in HSX, 14th International Stellarator Workshop, Greifswald, Germany, 2003.

2. Studies of Bias Induced Plasma Flows in HSX, 14^thInternational Stellarator Workshop, Greifswald, Germany, 2003.