Self-breakdown spark gap stability under rep-rate conditions

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6888582

Rinehart, L F; Buttram, M T

We have measured the statistical distribution of self-breakdown voltages of a spark gap at very low repetition rates (< 1 Hz) and at 20 and 40 pulses per second. For the high repetition rate experiments, the test switch discharged a resistively charged energy storage capacitor into a resistive load producing a simple R-C relaxation waveform across the spark gap. Typical discharge parameters were in the 10 to 35 kV, 10 to 20 kA range with about 1 ..mu..s pulse width. For the low rate work, a 20% reversal ringing waveform was used to reach higher discharge currents (up to 100 kA). An on-line computer data acquisition system was used to record and process large numbers of breakdowns, thus producing good statistical samples. The data show two distinct instabilities. At high currents (> 30 kA) those data that have a single simple distribution are of an extreme value form that is skewed toward low voltage. At low currents and higher repetition rates, the data evolve from a narrow dc (single pulse) breakdown voltage distribution into a broader Gaussian distribution at 20 pulses per second (pps) and finally to a very broad bimodal distribution (two Gaussians) at 40 pps. At 40 pps some firings occur as low as 30% of the mean. Effects of pressure and flow rate on the distributions are presented, and we discuss possible explanations for the origins of the distributions and their behavior.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6888582
• Report Number(s): SAND-83-2434C; CONF-8406137-4; ON: DE84013126
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420800* -- Engineering-- Electronic Circuits &amp; Devices-- (-1989)
BREAKDOWN
DATA ACQUISITION SYSTEMS
ELECTRIC POTENTIAL
PRESSURE DEPENDENCE
SPARK GAPS
STABILITY