TY - GEN
T1 - Gas evolution measurements in a sealed vircator tube
AU - Vara, John
AU - Walter, John
AU - Dickens, James
PY - 2010
Y1 - 2010
N2 - The gases evolved during operation of high power microwave devices, such as virtual cathode oscillators (vircators), can be detrimental to their power output, output pulse width, and maximum pulse repetition rate. Gases are evolved both from processes at the cathode (such as explosive electron emission) and at the anode (due to heating from the electron beam). In this project, a residual gas analyzer and pressure measurements have been utilized to characterize the gases generated during operation of a sealed vircator tube. The background pressure in the tube before firing is in the ultra-high vacuum range (∼10-8 Torr). The vircator is not pumped on during firing. After firing, the measurements are made, and then the tube is ion pumped back down to the background pressure before the next shot. Multiple anode and cathode materials will be tested, with measurements made of both the quantity and types of gases evolved during firing. Example test materials include stainless steel, OFHC copper, copper tungsten, and tantalum. For all tests, the vircator is driven directly from a low impedance Marx generator, with no intermediate pulse forming. The system design and diagnostic systems are described, and gas quantity and composition data is presented.
AB - The gases evolved during operation of high power microwave devices, such as virtual cathode oscillators (vircators), can be detrimental to their power output, output pulse width, and maximum pulse repetition rate. Gases are evolved both from processes at the cathode (such as explosive electron emission) and at the anode (due to heating from the electron beam). In this project, a residual gas analyzer and pressure measurements have been utilized to characterize the gases generated during operation of a sealed vircator tube. The background pressure in the tube before firing is in the ultra-high vacuum range (∼10-8 Torr). The vircator is not pumped on during firing. After firing, the measurements are made, and then the tube is ion pumped back down to the background pressure before the next shot. Multiple anode and cathode materials will be tested, with measurements made of both the quantity and types of gases evolved during firing. Example test materials include stainless steel, OFHC copper, copper tungsten, and tantalum. For all tests, the vircator is driven directly from a low impedance Marx generator, with no intermediate pulse forming. The system design and diagnostic systems are described, and gas quantity and composition data is presented.
UR - http://www.scopus.com/inward/record.url?scp=80051774023&partnerID=8YFLogxK
U2 - 10.1109/IPMHVC.2010.5958432
DO - 10.1109/IPMHVC.2010.5958432
M3 - Conference contribution
AN - SCOPUS:80051774023
SN - 9781424471294
T3 - Proceedings of the 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010
SP - 608
EP - 611
BT - Proceedings of the 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010
T2 - 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010
Y2 - 23 May 2010 through 27 May 2010
ER -