Title :
Residence time and charge state of silver and zinc ions generated from microsecond vacuum arcs
Author :
Tsuruta, Koichi ; Yamazaki, Naoto ; Watanabe, Gin-ichi
Author_Institution :
Dept. of Electr. & Electron. Eng., Ibaraki Univ., Hitachi, Japan
fDate :
8/1/1994 12:00:00 AM
Abstract :
One mm vacuum gaps with silver or zinc needle-cathode were fired by a 13 μs duration sinusoidal arc or a 9 μs duration exponentially decaying arc. Time-of-flight (TOF) ion measurements were made at variable ion extraction times after the arc ignition to measure the charge state and residence time of the ions. Ag+, Ag++ and Ag+++ ions were generated from silver cathode and Zn+ and Zn++ were generated from zinc cathode. Residual gas atom ions were generated together with the metal ions. Residence times of silver and zinc ions at the acceleration space, which was 15-25 mm apart from the needle cathode, were 5 μs and 17 μs, respectively, regardless the waveform of the arc current. Charge state fractions of silver and zinc ions were determined from the TOF ion currents and were compared with the results by other researchers
Keywords :
arcs (electric); plasma diagnostics; time of flight mass spectra; 13 mus; 15 to 25 mm; 17 mus; 5 mus; 9 mus; Ag; Ag+++; Ag++; Ag+; TOF ion currents; Zn; Zn++; Zn+; acceleration space; arc current; charge state; charge state fractions; ignition; ion extraction times; microsecond vacuum arcs; residence time; time-of-flight ion measurement; Acceleration; Cathodes; Charge measurement; Current measurement; Ignition; Needles; Silver; Time measurement; Vacuum arcs; Zinc;
Journal_Title :
Plasma Science, IEEE Transactions on
