HINST: A 2-D Code for High-n TAE Stability
- Princeton Plasma Physics Laboratory
A high-n stability code, HINST, has been developed to study the stability of TAE (Toroidicity-induced Alfvén Eigenmodes) in large tokamaks, such as ITER [International Thermonuclear Experimental Reactor], where the spectrum of unstable TAE modes is shifted toward medium- to high-n modes. The code solves the 2-D eigenmode problem by expanding the eigenfunction in terms of basis functions. Based on the Fourier-ballooning formalism the eigenmode problem is reduced to a system of coupled 1-D equations, which is solved numerically by using the finite element method and a SPARSE matrix solver. The numerical method allows including nonperturbatively non-ideal effects, such as: full ion FLR [Finite Larmor Radius], trapped-electron collisional damping, etc. The 2-D numerical results of TAE and Resonance TAE [RTAE] modes are compared with those from local ballooning calculations and global MHD NOVA code. The results show that for ITER-like plasma parameters, TAE and RTAE modes can be driven unstable by alpha particles for n = 10 - 20. The growth rate for the most unstable mode is within the range lambda divided by omega sub A approximately equal to 0.3 - 1.5%. The most unstable modes are localized near r = a approximately equal to 0.5 and have a broad radial mode envelope width.
- Research Organization:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ
- Sponsoring Organization:
- USDOE Office of Energy Research (ER)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 3758
- Report Number(s):
- PPPL-3295; ON: DE00003758
- Country of Publication:
- United States
- Language:
- English
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