TY - GEN
T1 - Statistical and formative delay times for sub-nanosecond breakdown at sub-atmospheric pressure
AU - Chaparro, Jordan
AU - Hatfield, Lynn
AU - Krompholz, Hermann
AU - Neuber, Andreas
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2008
Y1 - 2008
N2 - For subnanosecond switching, physical phenomena as well as basic breakdown data, such as delay times and breakdown voltages, are of interest. With a RADAN Puiser as source for voltage pulses with up to 180 kV amplitude and risetimes at a test gap of 180 ps, we investigate statistical and formative delays for argon and dry air at sub-atmospheric pressure, for gap widths of 1 and 11 mm. Formative times have minima between 50 and 200 torr, and range from 70 ps at 1.5 MV/cm to 200 ps at 50 kV/cm. For this range of electric fields, this dependence on pressure and applied field can be explained by the behavior of ionization coefficient and electron drift velocity for homogeneous discharges. For higher fields exhibiting a narrow ionization zone in cathode vicinity with pronounced electron runaway conditions, the experimental data agree with results of Monte-Carlo simulations. Statistical delays are about the same as formative delays at fields of 50 kV/cm, and are reduced with increasing field amplitude to less than 50 ps at 1.5 MV/cm. It appears that field emission is the major source for starting electrons, influencing the statistical delay time near the field emission threshold only.
AB - For subnanosecond switching, physical phenomena as well as basic breakdown data, such as delay times and breakdown voltages, are of interest. With a RADAN Puiser as source for voltage pulses with up to 180 kV amplitude and risetimes at a test gap of 180 ps, we investigate statistical and formative delays for argon and dry air at sub-atmospheric pressure, for gap widths of 1 and 11 mm. Formative times have minima between 50 and 200 torr, and range from 70 ps at 1.5 MV/cm to 200 ps at 50 kV/cm. For this range of electric fields, this dependence on pressure and applied field can be explained by the behavior of ionization coefficient and electron drift velocity for homogeneous discharges. For higher fields exhibiting a narrow ionization zone in cathode vicinity with pronounced electron runaway conditions, the experimental data agree with results of Monte-Carlo simulations. Statistical delays are about the same as formative delays at fields of 50 kV/cm, and are reduced with increasing field amplitude to less than 50 ps at 1.5 MV/cm. It appears that field emission is the major source for starting electrons, influencing the statistical delay time near the field emission threshold only.
UR - http://www.scopus.com/inward/record.url?scp=62949119316&partnerID=8YFLogxK
U2 - 10.1109/IPMC.2008.4743701
DO - 10.1109/IPMC.2008.4743701
M3 - Conference contribution
AN - SCOPUS:62949119316
SN - 9781424415359
T3 - Proceedings of the 2008 IEEE International Power Modulators and High Voltage Conference, PMHVC
SP - 503
EP - 506
BT - Proceedings of the 2008 IEEE International Power Modulators and High Voltage Conference, PMHVC
Y2 - 27 May 2008 through 31 May 2008
ER -