Note: Multi-point measurement of |B| in the gas-dynamic trap with a spectral motional Stark effect diagnostic

An upgraded spectral motional Stark effect diagnostic has been installed on the gas-dynamic trap (GDT) experiment to enable spatially resolved measurement of vertical bar B vertical bar. A new low-noise charge-coupled device detector, combined with enhancements of the diagnostic neutral beam, allows single-shot profile measurements. Previously only single-point motional Stark effect measurements were possible, and detector noise severely limited measurement precision, requiring multi-shot averaging. The plasma pressure profile in GDT is derived from the measured diamagnetic modification of vertical bar B vertical bar and used to examine the conditions of stable plasma confinement at high plasma pressure. (C) 2011 American Institute of Physics. [doi:10.1063/1.3624742]