TY - GEN
T1 - Initial anode optimization for a compact sealed tube vircator
AU - Walter, J.
AU - Vara, J.
AU - Lynn, C.
AU - Dickens, J.
AU - Neuber, A.
AU - Kristiansen, M.
PY - 2011
Y1 - 2011
N2 - During the development and optimization of a compact sealed tube virtual cathode oscillator (vircator) at Texas Tech University, it has become apparent that processes at the anode have a significant impact on tube performance. The impact of the high energy, high current density (100-200 A/cm 2 or higher) beam on the anode will cause outgassing, plasma production, and anode melting and material ejection. The emitted material expands, eventually impacting the anode transparency and (combined with the plasma formed at the cathode) shorting out the anode-cathode gap. This expansion limits the maximum radiated pulse width, and can also limit the peak output power. The residual evolved gas also negatively impacts the maximum repetition rate of the tube. An effort is underway to study the thermal behavior, gases evolved, and transparency versus time for different vircator anode materials and material treatments. Several different anode materials are under investigation, including stainless steel, copper tungsten, tantalum, nickel, and molybdenum. The effect of different treatments on the anodes before tube assembly is also being studied. The gases that are evolved during operation have been characterized utilizing pressure and residual gas analyzer measurements. The pre-shot background pressure in the tube is in the ultra-high vacuum range (10 -8 to 10 -9 Torr), and the vircator is not pumped on during firing. The data collected for the different materials is presented.
AB - During the development and optimization of a compact sealed tube virtual cathode oscillator (vircator) at Texas Tech University, it has become apparent that processes at the anode have a significant impact on tube performance. The impact of the high energy, high current density (100-200 A/cm 2 or higher) beam on the anode will cause outgassing, plasma production, and anode melting and material ejection. The emitted material expands, eventually impacting the anode transparency and (combined with the plasma formed at the cathode) shorting out the anode-cathode gap. This expansion limits the maximum radiated pulse width, and can also limit the peak output power. The residual evolved gas also negatively impacts the maximum repetition rate of the tube. An effort is underway to study the thermal behavior, gases evolved, and transparency versus time for different vircator anode materials and material treatments. Several different anode materials are under investigation, including stainless steel, copper tungsten, tantalum, nickel, and molybdenum. The effect of different treatments on the anodes before tube assembly is also being studied. The gases that are evolved during operation have been characterized utilizing pressure and residual gas analyzer measurements. The pre-shot background pressure in the tube is in the ultra-high vacuum range (10 -8 to 10 -9 Torr), and the vircator is not pumped on during firing. The data collected for the different materials is presented.
UR - http://www.scopus.com/inward/record.url?scp=84861381960&partnerID=8YFLogxK
U2 - 10.1109/PPC.2011.6191517
DO - 10.1109/PPC.2011.6191517
M3 - Conference contribution
AN - SCOPUS:84861381960
SN - 9781457706295
T3 - Digest of Technical Papers-IEEE International Pulsed Power Conference
SP - 807
EP - 810
BT - IEEE Conference Record - PPC 2011, Pulsed Power Conference 2011
T2 - 18th IEEE International Pulsed Power Conference, PPC 2011
Y2 - 19 June 2011 through 23 June 2011
ER -