NSTX Research

 

 

First Author Journal Publications:

 

1. 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).

 

2. 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).

 

3. 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).

 

4. 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).

 

5. 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).

 

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

 

7. 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 βN Control in the National Spherical Torus Experiment, Fusion Sci. Tech. 61, 11 (2012).

 

8. 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).

 

9. 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).

 

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

 

11. 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).

 

12. 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

 

13. 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).

 

Co-Authored Journal Publications:

 

1. 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).

 

2. 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).

 

3. 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).

 

4. 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).

 

5. 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).

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

 

7. 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).

 

8. 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).

 

9. 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).

 

10. 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).

 

11. 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).

 

12. 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).

 

13. 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).

 

14. 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).

 

15. 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).

 

16. 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).

 

17. 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).

 

18. 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).

 

19. 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).

 

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

 

21. 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).

 

22. 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).

 

23. 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).

 

24. 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)

 

25. 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).

 

26. 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).

 

27. 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)

 

28. 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).

 

29. 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).

 

30. 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).

 

31. 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).

 

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

 

33. 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).

 

34. 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).

 

35. 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).

 

36. 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).

 

37. 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).

 

38. 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).

 

39. 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).

 

40. 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).

 

41. 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).

 

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 National Spherical Torus Experiment, Phys. Plasmas 19, 062506 (2012).

 

43. 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).

 

44. 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).

 

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

 

46. 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).

 

47. 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).

 

48. 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).

 

49. 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).

 

50. 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).

 

51. 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).

 

52. 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).

 

53. 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).

 

54. 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).

 

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

 

56. 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 Alfvn Eigenmodes, submitted to Nuclear Fusion (2012).

 

57. 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).

 

58. 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).

 

59. 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).

 

60. 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).

 

61. 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).

 

62: 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).

 

63: 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 Alfvn eigenmodes, Phys. Plasmas 20, 042112 (2013).

 

64: 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).

 

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

 

 

Significant Presentations:

 

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

 

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

 

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

 

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

 

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

 

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

 

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

 

Conference Proceedings (all with associated poster or oral presentation)

 

1. 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 22nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper EX/5-1, (Geneva, Switzerland 2008), IAEA.

2. 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 22nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper IT/P6-8, (Geneva, Switzerland, 2008), IAEA.

 

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

 

4. 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 22nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper EX/P4-9, (Geneva, Switzerland, 2008), IAEA.

 

5. 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, 36th EPS Conference on Plasma Physics, Sofia, Bulgaria, 2009.

 

6. 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, 36th EPS Conference on Plasma Physics, Sofia, Bulgaria, 2009.

 

7. 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, 37th EPS Conference on Plasma Physics, Dublin, Ireland, 2010.

 

8. 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, 37th EPS Conference on Plasma Physics, Dublin, Ireland, 2010.

 

9. 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, 37th EPS Conference on Plasma Physics, paper P2-160, Dublin, Ireland, 2010.

 

10. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, Paper EXC/8-1, (Daejon, Korea, 2010), IAEA.

 

11. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

12. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

13. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

14. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

15. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

16. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

17. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

18. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

19. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

20. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

21. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

22. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

23. 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 23nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (Daejon, Korea, 2010), IAEA.

 

24. 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, 38th EPS Conference on Plasma Physics, paper P1.118, Strasbourg, France, 2011.

 

25. 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, 38th EPS Conference on Plasma Physics, paper P2.119, Strasbourg, France, 2011.

 

26. 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, 38th EPS Conference on Plasma Physics, paper P1.078, Strasbourg, France, 2011.

 

27. 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, 38th EPS Conference on Plasma Physics, paper P2.088, Strasbourg, France, 2011.

 

28. 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, 38th EPS Conference on Plasma Physics, paper P5.104, Strasbourg, France, 2011.

 

29. 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?, 38th EPS Conference on Plasma Physics, paper P3.109, Strasbourg, France, 2011.

 

30. 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, 39th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

 

31. 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, 39th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

 

32. 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, 39th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

 

33. 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, 39th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

 

34. 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, 39th EPS Conference on Plasma Physics, Stockholm, Sweden, 2012.

 

35. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

36. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

37. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

38. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

39. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

40. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

41. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

42. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

43. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

44. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

45. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

46. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

47. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.

 

48. 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 24nd International Conf. on Plasma Physics and Controlled Nuclear Fusion Research, (San Diego, USA, 2012), IAEA.