1. Code Name: Sweeping Equilibrium & Stability Code (SESC)

2. Category: IIa. Fixed boundary Plasma Equilibrium

3. Responsible Physicist: Leonid E. Zakharov

5.One line description: Interactive code for massive processing experimental data and comparing with the theory.

6. Computer systems which code runs on: Any Unix machine

7. Typical running time: 5-30 sec/case

8. Approximate number of code lines: 20,000

9. Does this code read data files from another code?

10. Does this code produce data files that can be read by another code? All the internal profiles a represented in terms of splines. So, the interface with any other code is trivial. Interface with PEST, DCON, MARS is in the current version. SESC is used by ASTRA (transport simulation) as an equilibrium solver.

11. 1-2 paragraph description of code: Code uses Newton scheme in its most efficient form to solve the nonlinear Grad-Shafranov equation. For solving intermediate linearized Grad-Shafranov equation it uses gridless (sweeping) technique, which guarantees a prescribed accuracy.

12. Similar codes to this code, and distinguishing differences: Compared with JSOLVER, SESC allows to use any combination of input profiles which determines plasma pressure and the current density. Compared with ballooning stability codes, SESC contains full two-fluid model, which is necessary for the present day experiments.

13. Journal References describing code: Not available.

14. New code capabilities planned for next 1-2 years: Full low- and intermediate-n linear stability in two-fluid version.

15. Code users: L. Zakharov

16. Present and recent applications of code: TFTR stability studies.

17. Status of code input/output documentation. Check one: ( ) does not exist ( ) incomplete ( X ) exists Code is written with use of FWEB SYSTEM

18 Year Code was first used and present frequency of use: 1994. In continues use and upgrading.

19. Estimate of Man-Years invested in developing code: 2

20. Catagories of usage of Code (Check all that apply): (X) application code to do analysis and prediction of experiments (X) numerical testbed of theoretical ideas (X) physics module to be used in integrated moddelling ( ) code for machine design

21. Language code is written in: C+Fortran

22. Results of intercomparisons with other codes and results of validation against experiments. Equilibrium part has been proved to be more accurate than Drozdov's POLAR equilibrium solver. In its simples form (ideal one fluid MHD), ballooning stability part of SESC has been verified with M.Chance and A.Glasser ballooning codes. Compared with the TFTR data: 1. The code proved that widely used one-fluid theory does not fit the experiment in essential details. 2. The code revealed the role of ballooning modes in TFTR high-beta disruption triggering. 3. The code predicts appearance, frequency and range of wave numbers of so-called "Kinetic" (really MHD) ballooning modes in TFTR.