TY - GEN
T1 - The influence of a DC electric field on high power microwave window flashover in air and N2 environments
AU - Foster, J.
AU - Thomas, M.
AU - Krompholz, H.
AU - Neuber, A.
PY - 2009
Y1 - 2009
N2 - Observed delay times for high power microwave surface flashover are influenced significantly by the presence of a DC electric field. The experimental setup to investigate theses influences is comprised of an S-band magnetron operating at 2.85 GHz with a pulse rise time shortening switch assembly that produces a 50 ns rise time at a ∼ 2.5 MW power level. A wire electrode charged to ±20 kV is inserted into the dielectric interface perpendicular to the electric field of the TE10 mode to provide a DC electric field in the flashover region. Tests have been conducted in pure N2 at 125 torr in order to provide an environment composed of primarily electrons and positive ions. The average measured delay of window flashover with a DC field pointing into the dielectric has been observed to increase by ∼50%. Additionally, effective emission rates of seed electrons initiating breakdown have shown a decrease from 14 e/μs to 2 e/μs, indicating the removal of charged species from the high microwave field region due to charge drift in the applied DC field. An overview of the experimental setup is given along with a statistical analysis of delay times measured in Air as well as N2. The open question of where seed electrons originate from and the quantification of the primary processes involved will be addressed.
AB - Observed delay times for high power microwave surface flashover are influenced significantly by the presence of a DC electric field. The experimental setup to investigate theses influences is comprised of an S-band magnetron operating at 2.85 GHz with a pulse rise time shortening switch assembly that produces a 50 ns rise time at a ∼ 2.5 MW power level. A wire electrode charged to ±20 kV is inserted into the dielectric interface perpendicular to the electric field of the TE10 mode to provide a DC electric field in the flashover region. Tests have been conducted in pure N2 at 125 torr in order to provide an environment composed of primarily electrons and positive ions. The average measured delay of window flashover with a DC field pointing into the dielectric has been observed to increase by ∼50%. Additionally, effective emission rates of seed electrons initiating breakdown have shown a decrease from 14 e/μs to 2 e/μs, indicating the removal of charged species from the high microwave field region due to charge drift in the applied DC field. An overview of the experimental setup is given along with a statistical analysis of delay times measured in Air as well as N2. The open question of where seed electrons originate from and the quantification of the primary processes involved will be addressed.
UR - http://www.scopus.com/inward/record.url?scp=77949982414&partnerID=8YFLogxK
U2 - 10.1109/PPC.2009.5386323
DO - 10.1109/PPC.2009.5386323
M3 - Conference contribution
AN - SCOPUS:77949982414
SN - 9781424440658
T3 - PPC2009 - 17th IEEE International Pulsed Power Conference
SP - 480
EP - 483
BT - PPC2009 - 17th IEEE International Pulsed Power Conference
T2 - 17th IEEE International Pulsed Power Conference, PPC2009
Y2 - 28 June 2009 through 2 July 2009
ER -