Results of fiber optic interferometer measurements on a magnetically confined plasma opening switch

Summary form only given. Fiber optic interferometer (FOI) plasma density measurements were performed on a magnetically confined plasma opening switch (MCPOS) at the Centre d'Etudes de Gramat, France. This is the first time that direct density measurements have been carried out on the MCPOS. The MCPOS uses a quasi-static magnetic field (slow-coil field) to guide the flashboard plasma into the anode-cathode (AK) gap and a separately generated fast field to open the switch. Measurements were performed on both the flashboard fill-plasma and plasma with the Marx bank fired. It was found that the flashboards generate a plasma with a density of about /spl sim/10/sup 14/ cm/sup -3/ which travels with a maximum velocity, v/spl sim/15 cm//spl mu/s.