Particle kinetic-energy measurement in compact toroidal injection into a gas neutralizer

Particle kinetic-energy measurement in the experiments of compact toroid (CT) injection into a hydrogen gas neutralizer is presented. The typical injected CT parameters are: (1-4)x1021 m-3 in electron density and 30-70 km·s-1 in velocity. By using microchannel plate detectors, kinetic-energy of ions and neutrals after CT passing the neutralizer has been measured with an electrostatic ion energy analyzer and evaluated by time-of-flight method, respectively. The pressure in the neutralizer was scanned. At the pressure approx. = 6x10-3 torr, charge exchange between CT plasma and the neutral particles with high energy has been identified, which is characterized by significant decay of CT plasma density and magnetic field profile. The velocity of the produced neutral particle flow is close to the ion velocity of the CT plasma. (author)