Field reversed configuration lifetime scaling based on measurements from the Large s Experiment

Abstract

Flux, energy and particle lifetimes have been measured in the new Large s Experiment field reversed configuration (FRC) facility. By careful control of the formation process, it was possible to form symmetric, quiescent FRCs, with s values higher than 4, in the one year of operation of the device. A wide range of plasma conditions was achieved, with ion temperatures varying between 0.1 and 1.5 keV. The lifetimes continue to scale approximately with the rs2/ρi parameter found in earlier work, with a coefficient proportional to xs to a power between 0.5 and 1

Achieving a long-lived high-beta plasma state by energetic beam injection

“…1) [10][11][12][13] , an effort entirely funded by private resources. It has recently achieved a long-lived FRC regime, with a marked improvement in confinement over one order of magnitude, departing from the predictions based on the scaling law in the previous experiments 14 .…”

“…Coupling these active boundary control techniques with NBI, we have achieved long-lived FRCs, with the lifetime approaching 5 ms, far beyond the conventional theta-pinch-formed FRCs 4,14,19,20 , as shown in Fig. 2.…”

The Pulsed High Density Experiment: Concept, Design, and Initial Results

“…The initial goal of an initial Pulsed High Density experiment (PHDX) is to form, accelerate and compress an FRC to a density of 1 Â 10 22 m )3 at a temperature greater than 1 keV. With the energy confinement time predicted by previous FRC scaling [3], the FRC should attain a ns product of 5 Â 10 18 m )3 s, which would exceed previous FRC results by nearly an order of magnitude. This experiment would essentially be the first step, where progress towards breakeven can be made in incremental steps with additional stages of acceleration and compression based on the successful completion of this first phase.…”

MHD Activity in an Extremely High-Beta Compact Toroid

“…al., 1993). At the same time, the FRTP-based formation method has been significantly improved (Slough et al, 1989;Hoffman et al, 1993;Pietrzyk et al, 1987;Pierce et al, 1995;Guo et al, 2004Asai et al, 2000;Binderbauer et al, 2010;Guo, et al, 2011). Recently initiated new formation methods include (1) counter-helicity spheromakmerging (CHSM) (Yamada et al, 1990;Ono et al, 1993;Gerhardt et al 2008), (2) rotating magnetic field (RMF) (Slough & Miller, 2000;Knight & Jones, 1990;A.…”

“…Improved FRTP methods have also introduced low inductive voltage and program formation by FRTP (Slough et al, 1989;Hoffman et al, 1993), the coaxial slow source (CSS) (Pietrzyk et al, 1987;Pierce et al, 1995), translation-trapping formation by FRTP (Guo et al, 2004Asai et al, 2000), and collision FRC merging by FRTP (Binderbauer et al, 2010;Guo et al, 2011). Through these innovative new methods and improved FRTP methods, the FRC lifetime has been prolonged to the order of several ms, and the confinement properties have also been improved [34].…”