SPECTROSCOPIC MEASUREMENTS OF ELECTRON-DENSITY AND TEMPERATURE IN POLYACETAL-CAPILLARY-DISCHARGE PLASMAS

Spectroscopic measurements were made of electron density and temperature histories in plasmas formed by 80-ns risetime, 6-16-kA peak current, pulsed discharges in 0.5- and 1-mm diameter, 1-cm-long polyacetal (CH2O)n capillaries. Electron densities (less than or similar 5 X 10(19) cm-3) and temperatures (less than or similar 50 eV) in the capillary were inferred by fitting axial, spatially integrated, time-gated spectra taken of O VI 3p-4d and 3d-4f emission with theoretical Stark-broadened profiles that were corrected for optical-depth effects. Off-axis (at 45-degrees to the capillary axis) time-gated spectra taken of C III 3p-3d and CIV 3s-3p emission from inside the hollow anode were used to infer the presence of a cooler (T(e) less-than-or-similar 25 eV), less dense (N(e) less than or similar 2 X 10(18) cm-3) plasma just outside the capillary.