Presentation by Herb Berk University of Texas at Austin Institute for Fusion Studies in Vienna, Austria Sept. 1-4, 2015

Transcription

1 Review of Theory Papers at 14 th IAEA technical meeting on Engertic Particles in Magnetic Confinement systems Presentation by Herb Berk University of Texas at Austin Institute for Fusion Studies in Vienna, Austria Sept. 1-4,

2 Cartoon of Stiff Critical Gradient 2

3 Can we infer transport from marginal stability alone O-6: Gorelenkov Assumes Marginal Stability Independent of Velocity Space matches neutron deficit using marginality to TAE +BAAE (EPM) modes 3

4 Kick Model (Podesta O-1) 4

5 Podesta (O-1) Treatment of fast ion phase space evolution relevant for consistent integrated simulations Two models tested for fast ion transport in integrated simulations: Ad-hoc diffusion model, purely radial diffusion Phase space resolved kick model Retains correlation in E, P variations from resonant interactions Ad-hoc model OK for global quantities (e.g. neutrons, stored energy) But: substantial differences observed for profiles, time evolution of Fast ion density, NB-driven current Fast ion distribution function J NB peaking J NB peaking incremental - incr. transport ad-hoc D b kick model J NB peaking J NB peaking classical - classical transport Profiles of NB-driven current from TRANSP classical ad-hoc D b NSTX # kick model 5

6 Neutron Deficit Reproduced 6

7 R. Waltz O-3 7

8 8

9 Heidbrink (I-3) 9

10 Guoyong Fu (I-6) 10

11 As frequency Pφ & E change Pφ - ne/ω =constant (n=1 for fishbone) 11

12 X. Wang (I-9) 12

13 Surprise element, chirp without bucket? chirp time ~ ½ trapping time; Constraint requirement (dω/dt)/(ω b ) 2 <1 & nearly constant 13

14 Gogaccia & Vlad (P-30) Also see: M. Cole: (I:12); NON-LINEAR GYROKINETIC CODE FOR REALISTIC TOKAMAK FOR HAS SPECIALIZED IN EPM & NONLINEAR EFFECTS 14

15 A. Bierwage (I-10) Introductory Talk that Asks the question of whether we can heat ions having unstable beta Alfven waves heat plasma by simultaneously resonating with acoustic branch (kinetically ion Landau damping) See also Biancalani-(I-7) Attempting formulate a very generalized set of nonlinear kinetic equations. 15

16 Y. Todo (O-19) 16

17 Y. Todo Beam deposition power (P NBI ) scan was performed with multiphase hybrid simulation for DIII-D experiments. It was found in the simulation results: Fast-ion confinement degrades steadily with increasing power. Normalized ast-ion pressure profile converges to a stiff profile as the phase space is covered by the transport regions with P NBI increase. For the stiff profile, the whole phase space should be fully covered by the overlapped transport regions up to the particle loss location. Transport barrier exists at the edge. Careful modeling of the edge transport and particle loss is important

18 Puzzle: How are avalanches explained?? Lauber: P-27 Asdex data NSTX- Data 18

19 P. Rodrigues (O-11) Can anything be done to quench alpha driven Alfvenic Instability 19

20 J. Ferreira (P-22) In this case continuum is very well aligned 20

21 D. Spong (O-16) Stellarator, appears much harder calculation but often very similar; but with additional gaps 21

22 Melnikov (0-18) Chirping measured with HIBP on TJ-II stellarator HIBP B pol MP B pol <n e > < 0.6 x10 19 m -3 Coh HIBP MP High coherence (Coh ~ 0.9) between B pol oscillations (HIBP) at Mirnov probes signals is observed for chirping modes

23 D. Pfefferle (I-4) Ripple due to toroidal field coils in Demo 23

24 How to analyze ripple? 24

25 Electron Runaways Avalanche from relativistic knock ons (Rosenbluth & Putvinski) Papers: G. Papp O-21; A. Stahl (P-31) Z. Chen O-22 (runaways in J-TEXT tokamak) 25

26 G. Papp (O-21) 26

27 FINIS 27

28 28

29 Effects of fast ion phase space modifications by instabilities on fast ion modeling M. Podestà, M. Gorelenkova, E. Fredrickson, N. Gorelenkov, R. White PPPL, Princeton USA Acknowledgements: NSTX-U and DIII-D Energetic Particles groups 14th IAEA-TM on Energetic Particles Vienna, Austria September th IAEA-TM, Fast ion by modeling phase space M. Podestà, Sep Supported DOEwith contract no. modifications, DE-AC02-09CH

30 One scenario for particle containment (Berk-Breizman) One scenario for particle containment (Berk-Breizman) 30

31 M. Schneller (O-8) 31