Magnetic field and electron density evolutions in a POS

Summary form only given. We study the operation of a planar microsecond plasma opening switch (POS) in which a current of 140 kA is conducted by the plasma for a duration of 400 ns before opening into an inductive load within 90 ns. Spectroscopic measurements, local in 3D, are made by doping the plasma with various species and observing the characteristic emission of the doped particles. The electron density and temperature and the plasma composition of the prefilled flashboard plasma are studied spectroscopically. The electron density and temperature are found to be (5/spl plusmn/2)/spl times/10/sup 14/ cm/sup -3/ and 6/spl plusmn/0.5 eV, respectively. The plasma is found to consist mainly of protons with a significant fraction of C IV and C V ions only near the anode. During the POS operation, measurements of the magnetic field evolution from Zeeman splitting, the electron density and temperature from line intensities and collisional-radiative calculations, and the ion velocities from Doppler shifts are made.