Investigation of the effect of pre-fill gas in VEST discharges by predictive transport simulations

다국어 초록 (Multilingual Abstract)

The predictive modeling of the VEST (Chung et al. in Plasma Sci Technol 15(3):244, 2013) device is presented. The integrated simulation tool was organized to conduct the 1D transport simulation considering neoclassical and turbulent transport, and pre-fll gas neutrals. The 1D transport equation and a detailed setup for the predictive analysis were addressed. By varying pre-fll gas levels, a set of predictive simulations was conducted. The electron density, electron and ion temperatures from Thomson scattering, and ion Doppler spectroscopy diagnostics were compared with the predictive simulation results. The discrepancies upon comparing the measurements with the simulations and further required eforts were discussed.

참고문헌 (Reference)

1 D. Kim, "Upgrade of Thomson scattering system on VEST" 146 : 1131-, 2019

2 L. Spitzer, "Transport phenomena in a completely ionized gas" 89 (89): 977-, 1953

3 G. D. Garstka, "The upgraded Pegasus Toroidal Experiment" 46 (46): S603-, 2006

4 Sykes, A., "The START spherical tokamak" IEEE 2 : 1442-1446, 1995

5 H. Lütjens, "The CHEASE code for toroidal MHD equilibria" 97 (97): 219-, 1996

6 D. E. Post, "Steady-state radiative cooling rates for low-density, high-temperature plasmas" 20 (20): 397-, 1977

7 J. Yang, "Simple and accurate method of diamagnetic flux measurement in Versatile Experimental Spherical Torus(VEST)" 89 (89): 103508-, 2018

8 J. -H. Kim, "Radial profile measurement with an improved 1 kHz Thomson scattering system on Versatile Experiment Spherical Torus" 92 (92): 043549-, 2021

9 J. E. Kinsey, "Predictions of the near edge transport shortfall in DIII-D L-mode plasmas using the trapped gyro-Landau-fluid model" 22 (22): 012507-, 2015

10 S. M. Kaye, "Physics design of the national spherical torus experiment" 36 (36): 16-, 1999

11 Y. S. Na, "On hybrid scenarios in KSTAR" 60 (60): 086006-, 2020

12 Y. S. Na, "On benchmarking of simulations of particle transport in ITER" 59 (59): 076026-, 2019

13 E. Fable, "Novel free-boundary equilibrium and transport solver with theory-based models and its validation against ASDEX upgrade current ramp scenarios" 55 (55): 124028-, 2013

14 G. M. Staebler, "Gyro-Landau fluid equations for trapped and passing particles" 12 (12): 102508-, 2005

15 A. Sykes, "First results from MAST" 41 (41): 1423-, 2001

16 B. Scott, "E×B shear flows and electromagnetic gyrofluid turbulence" 7 (7): 1845-, 2000

17 Ono, M., "Exploration of spherical torus physics in the NSTX device" 40 (40): 557-, 2000

18 Y. An, "Efficient ECH-assisted plasma start-up using trapped particle configuration in the versatile experiment spherical torus" 57 (57): 016001-, 2017

19 C. Y. Lee, "Development of integrated suite of codes and its validation on KSTAR" 61 (61): 096020-, 2021

20 S. Kim, "Development of diverted plasma discharge and plan for advanced divertor study in VEST" 123 : 584-, 2017

21 전영무, "Development of a Free-boundary Tokamak Equilibrium Solver for Advanced Study of Tokamak Equilibria" 한국물리학회 67 (67): 843-853, 2015

22 Y. -G. Kim, "Development of Thomson scattering system on VEST" 143 : 130-, 2019

23 Y. Kim, "Design of combined system of helium charge exchange spectroscopy and hydrogen beam emission spectroscopy in VEST" 123 : 975-, 2017

24 K. J. Chung, "Design features and commissioning of the Versatile Experiment Spherical Torus(VEST)at Seoul National University" 15 (15): 244-, 2013

25 J. Park, "Design and development of the helicity injection system in Versatile Experiment Spherical Torus" 96–97 : 269-, 2015

26 A. Sykes, "Compact fusion energy based on the spherical tokamak" 58 (58): 016039-, 2018

27 K. Lee, "Commissioning and initial heating results of the neutral beam injection system in Versatile Experiment Spherical Torus" 171 : 112735-, 2021

28 W. A. Houlberg, "Bootstrap current and neoclassical transport in tokamaks of arbitrary collisionality and aspect ratio" 4 (4): 3230-, 1997

29 S. Kim, "Acceleration of ion rotation during internal reconnection events in the versatile experiment spherical torus(VEST)" 61 (61): 126011-, 2021

30 Pereverzev, G., "ASTRA User Guide" IPP 2002

31 G. M. Staebler, "A theory-based transport model with comprehensive physics" 14 (14): 055909-, 2007

32 S. Tamor, "A code for calculation of neutral transport in cylindrical plasmas" 40 (40): 104-, 1981