Formation of a long-lived hot field reversed configuration by dynamically merging two colliding high-β compact toroids

Abstract

A high temperature field reversed configuration (FRC) has been produced in the newly built, world’s largest compact toroid (CT) facility, C-2, by colliding and merging two high-β CTs produced using the advanced field-reversed θ-pinch technology. This long-lived, stable merged state exhibits the following key properties: (1) apparent increase in the poloidal flux from the first pass to the final merged state, (2) significantly improved confinement compared to conventional θ-pinch FRCs with flux decay rates approaching classical values in some cases, (3) strong conversion from kinetic energy into thermal energy with total temperature (Te + Ti) exceeding 0.5 keV, predominantly into the ion channel. Detailed modeling using a new 2-D resistive magnetohydrodynamic (MHD) code, LamyRidge, has demonstrated, for the first time, the formation, translation, and merging/reconnection dynamics of such extremely high-β plasmas.