Particle and recycling control in translation, confinement, and sustainment upgrade
2010; American Institute of Physics; Volume: 17; Issue: 3 Linguagem: Inglês
10.1063/1.3339907
ISSN1527-2419
AutoresJ. A. Grossnickle, G. Vlases, A. L. Hoffman, Paul Melnik, R. D. Milroy, A. Tankut, Katherine Velas,
Tópico(s)Superconducting Materials and Applications
ResumoPrevious work in the translation, confinement, and sustainment upgrade (TCSU) device [H. Y. Guo et al., Phys. Plasmas 15, 056101 (2008)] demonstrated improved plasma parameters; higher temperature, higher poloidal magnetic field, increased current drive, and increased energy confinement, for rotating magnetic field (RMF) driven field reversed configurations (FRC) relative to the earlier TCS device. This was accomplished by improving vacuum conditions and using moderate wall heating (∼100 °C) and glow discharge cleaning for wall conditioning. Two new wall conditioning techniques, siliconization and titanium gettering, have been employed to further reduce impurities and control recycling. Both techniques reduced oxygen line radiation by an order of magnitude, and total radiated power by 50%, but led to little change in overall FRC performance, reinforcing the earlier conclusion that TCSU FRCs are not radiation dominated. Titanium gettering substantially reduced deuterium recycling, requiring a new method of fueling to be developed. This is the first time a FRC has been operated without using wall recycling as the primary method of fueling. The low-recycling FRCs, maintained by enhanced puff fueling, performed similarly to standard recycling fueled FRCs in terms of a key current drive parameter Be/Bω, the ratio of maximum sustained poloidal field to applied RMF field, but better density control allowed for higher temperatures.
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