Plasma stability and confinement in the PBX-M tokamak

Summary form only given. The PBX-M physics program exploits strong plasma shaping, control of the pressure and current profiles, and a close-fitting conducting wall for the understanding and optimization of plasma stability and confinement. Transport studies and ITER and CIT R&D-relevant studies of high-performance plasmas have focused on: (1) high-beta (⟨β⟩~6.8%) plasma with good energy confinement and high-temperature; (2) high-beta relative to the Troyon limit: (3) highly-indented (i~30%) plasmas. using plasma current ramps to drive the necessary edge current; (4) H-mode phases in both limited and diverted discharges; (5) current profile control by current ramping, counterneutral beam injection, and pellet injection: (6) development of j(r) diagnostics and initial studies of q(r) effects on sawteeth and fishbones: (7) modifications of disruption precursor growth rates and mode structure; and (8) disruptive vertical displacement events