| Autor: |
Tuszewski, M., Taggart, D. P., Chrien, R. E., Rej, D. J., Siemon, R. E., Wright, B. L. |
| Předmět: |
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| Zdroj: |
Physics of Fluids B: Plasma Physics; Oct91, Vol. 3 Issue 10, p2856, 15p |
| Abstrakt: |
Detailed stability studies are made with new diagnostics in the FRX-C/LSM field-reversed theta pinch [Plasma Physics and Controlled Nuclear Fusion Research (IAEA, Vienna, 1989), Vol. II, p. 517]. These studies seek the origin of a degradation of the confinement properties of field-reversed configurations (FRC’s) that appears associated with strong axial dynamics during plasma formation. Several instabilities are observed, including rotational modes, interchanges, and tilt instabilities. Only the latter are strongly correlated with FRC confinement. Tilt instabilities are observed for FRC’s with larger average number of ion gyroradii (s∼3–5) and smaller separatrix elongations (e∼3–4). Coincidently, strong axial dynamics occurs for cases with larger s and smaller e values, through increases in either reversed bias field or fill pressure. These data provide some understanding of FRC stability. In agreement with finite Larmor radius theory, there is a regime of gross stability for the very kinetic and elongated FRC’s with s/e<0.2–0.3. This is the regime that has been studied in most FRC experiments. However, tilt and other instabilities are observed for FRC’s with s/e∼1. Additional stabilization techniques will be required for future large-size FRC’s. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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