Temperature profiles in a shock front in a translating FRC plasma

The evolution of pressure balance and perpendicular Doppler temperature of field-reversed-configuration (FRC) plasma is examined experimentally. The pressure balance temperature increases gradually after the thermalization, and the rise is typically a factor of 2-3. In this thermalization process, measured Doppler profiles show non-Maxwellian. Such less thermal relaxation continues during more than 50 μs. Estimated perpendicular ion temperature increases from 40 eV to 80 eV before and after the thermalization. Thus values of the ratio of the perpendicular electron to the ion temperature are inferred to be 0.5 at first transit, 0.25 just after thermalization, and 0.7 at almost equilibrium phase of the translated FRC. This indicates that higher ion temperature than electrons attains during translation even under the condition that allows the FRC to be thermalized by some shock mechanism. (author)