A high performance field-reversed configurationa)

Abstract

Overview of C-2 field-reversed configuration experiment plasma diagnosticsa) Rev. Sci. Instrum. 85, 11D836 (2014); 10.1063/1.4884616 Density fluctuation measurements by far-forward collective scattering in the MST reversed-field pincha) Rev. Sci. Instrum. 83, 10E302 (2012);A new high performance field reversed configuration operating regime in the C-2 devicea)Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of $1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation. V C 2015 AIP Publishing LLC. [http://dx.

Formation and sustainment of field reversed configuration (FRC) plasmas by spheromak merging and neutral beam injection

“…(1). Very recently in the high performance FRC plasma, the above relationship was also experimentally verified by Binderbauer et al [30]. Figure 1 demonstrates a relationship between evolution of the C-2 discharges and the value of S*/E.…”

“…Plasma shaping, conducting shells, and the NBI would provide stabilization to MHD modes. This generic idea has been verified in C-2 experiment carried out recently at Tri Alpha Energy Company [30]. Although promising FRC reactor concepts have been developed in the past [4], a reactor design is outside the scope of the present paper, The physics basis for the SPIRIT concept has been verified in numerical calculations [6][7][8][9][10][11][12][13], as well as oblate FRC experiments.…”

“…A good portion of the SPIRIT concept has recently been verified by the C-2 experiments whose project was independently conceptualized and carried out [29,30]. They first created a hot FRC by supersonic merging of two high beta FRC plasmas.…”

“…The ion temperature approached near 1 keV and they achieved a still longer life time of 10 msec. [30].…”

“…Open symbols indicate the further progression of the discharge after onset of instability. From Binderbauer et al [30].…”