Accessibility for lower hybrid waves in PBX-M

Technical Report · Thu Jul 01 00:00:00 EDT 1993

DOI:https://doi.org/10.2172/10169809· OSTI ID:10169809

Takahashi, H; Bell, R; Bernabei, S; Chance, M; Chu, T K; Gettelfinger, G; Greenough, N; Hatcher, R; Ignat, D; Jardin, S; Kaita, R; Kaye, S; Kugel, H; LeBlanc, B; Manickam, J; Okabayashi, M; Ono, M; Paul, S; Perkins, F; Sauthoff, N ; Sesnic, S; Sun, Y; Tighe, W; Valeo, E; von Goeler, S ^[1]; Batha, S; Levinton, F ^[2]; Dunlap, J; England, A; Harris, J; Hirshman, S; Isler, R; Post-Zwicker, A ^[3]; Jones, S; Kesner, J; Luckhardt, S; Paoletti, F ^[4]; Schmitz, L; Tynan, G ^[5]

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1. Princeton Univ., NJ (US). Plasma Physics Lab.
2. Fusion Physics and Technology, Torrance, CA (US)
3. Oak Ridge National Lab., TN (US)
4. Massachusetts Inst. of Tech., Cambridge, MA (US)
5. Univ. of California, Los Angeles, CA (US)

Understanding the wave damping mechanism in the presence of a `spectral gap` is an important issue for the current profile control using Lower Hybrid Current Drive (LHCD). The authors examine a traditional explanation based upon upshifting of the wave parallel refractive index (n{sub {parallel}}) and find that there can be an upper bound in the n{sub {parallel}} upshift. The amount of upshift is not sufficient to bridge the spectral gap completely under some PBX-M LHCD conditions. There is experimental evidence, however, that current was driven even under such conditions. Another mechanism is also considered, based upon the 2-D velocity space dynamics coupled with a compound wave spectrum, here consisting of forward- and backward-running waves. The runaway critical speed relative to the phase speeds of these waves plays an important role in this model.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 10169809
• Report Number(s): PPPL-2920; ON: DE93017513; TRN: 93:016723
• Resource Relation: Other Information: PBD: Jul 1993
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PBX DEVICES
LOWER HYBRID HEATING
PLASMA WAVES
HYBRID RESONANCE
LOWER HYBRID CURRENT DRIVE
DAMPING
REFRACTIVE INDEX
LIMITING VALUES
ELECTRONS
OPERATION
EXPERIMENTAL DATA
WAVE FORMS
ELECTRON DRIFT
PHASE VELOCITY
700340
700350
PLASMA WAVES, OSCILLATIONS, AND INSTABILITIES
PLASMA PRODUCTION, HEATING, CURRENT DRIVE, AND INTERACTIONS