"C-2-Upgrade Field Reversed Configuration Experiment," Richard Magee and Artem Smirnov (Tri Alpha Energy, Inc.)

Friday, January 29, 2016 - 2:00pm to 3:00pm
Plasma Seminars

Plasma Seminar

Physics & Astronomy Building (PAB) 4-330
Friday, January 29, 2016
2-3 PM

Guest Speaker: Richard Magee and Artem Smirnov (Tri Alpha Energy, Inc.)​

Talk Title: "C-2-Upgrade Field Reversed Configuration Experiment"


In the C-2 field-reversed configuration (FRC) experiment [1], tangential neutral beam injection (20 - 40 keV hydrogen, ~ 4 MW total), coupled with electrically-biased plasma guns at the plasma ends, magnetic end plugs, and advanced surface conditioning, led to dramatic reductions in turbulence-driven losses and greatly improved plasma stability [2, 3]. Under such conditions, highly reproducible FRCs with a significant fast-ion population and total plasma temperature of ~ 1 keV were achieved [4]. The FRC’s were macroscopically stable and decayed on characteristic transport time scale of a few milliseconds.

In order to sustain an FRC configuration, the C-2 device was recently upgraded with a new neutral beam injection (NBI) system, which can deliver a total of 10+ MW of hydrogen beam power, by far the largest ever used in a compact toroid plasma experiment. As compared with C-2, the beam energy was lowered to 15 keV, and the injection geometry was changed to provide better beam coupling to the FRC.

The upgraded neutral beams produce a dominant fast ion population (fast ion pressure up to 60% of the thermal plasma pressure) that has a dramatic beneficial impact on the overall plasma performance.  Specifically: (1) high-performance, advanced beam-driven FRCs were produced and sustained for times significantly longer (5+ ms) than all characteristic plasma decay times without the beams, (2) the sustainment is correlated with neutral beam injection, (3) confinement of fast ions is close to the classical limit, and (4) new, benign collective fast ion effects were observed. Collectively, these accomplishments represent a dramatic advance towards the scientific validation of the FRC-based approach to fusion. This presentation will provide an overview of the C-2U device and recent experimental advances.

[1] M.W. Binderbauer et. al, Phys. Rev. Lett 105, 045003 (2010)

[2] M. Tuszewski et. al, Phys. Rev. Lett 108, 255008 (2012)

[3] H.Y. Guo et al., Nature Comm 6, 6897 (2015)

[4] M.W. Binderbauer et al., Phys. Plasmas 22, 056110 (2015)


PAB 4-330