Investigation of a Plasma from an Occluded Gas Cold Plasma Source

Results are given for various measurements made on a plasma from a hydrogen-loaded titanium washer mounted at a dc magnetic mirror (∼6 kG), the power being supplied to the source by a variable length pulse line (15–635 μsec). Spectroscopic studies indicated the presence of H, Ti+, Ti++, Ti+++, O+, O++, Al, Al+, Al++, and Ta+. Doppler shift measurements showed ion velocities from 5 × 105 to 2 × 106 cm/sec. Microwave cutoff measurements provided time history curves of electron density and indicated that the maximum density exceeded 3 × 1014 electrons per cm3. Profile measurements using a thermistor close to the aperture of the plasma gun revealed that 10% of the particles were neutrals. Probe measurements showed that the electron temperature decreased during the pulse from 15 to 1 eV and from 3 to <1 eV for old and new source washers, respectively.