Strong recombination peaks were observed at He-, Ne-, and Ar-ion lines in the afterglow of a pulsed, helical hollow-cathode discharge excited by 10 Hz, 0.5-100 μs duration and 1-23 A rectangular current pulses. The intensity of the peaks depended strongly on the high-voltage leading part of the exciting pulse. An optimum was found in the peak intensity as a function of pulse length. The peaks could not be observed at pulses exceeding a certain duration. From results obtained using double-pulse excitation, the peaks are considered to be due to recombination of doubly ionized atoms produced by the high-voltage leading edge of the exciting pulse with thermal-energy electrons. Line intensity investigations using an optical resonator indicate the possibility of gain at the He II 468.6 nm transition.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)
- Physics and Astronomy(all)