TY - GEN
T1 - High efficiency nonequilibrium air plasmas sustained by high energy electrons
AU - Miles, Richard B.
AU - Macheret, Sergey O.
AU - Shneider, Mikhail N.
N1 - Publisher Copyright:
© 2002 IEEE.
PY - 2015
Y1 - 2015
N2 - The Air Plasma Ramparts MURI goal is to sustain a volume-filling, nonequilibrium plasma with an electron number density of 1013 electrons/cm3 in atmospheric pressure air at temperatures at or below 2000 K, with the minimum expenditure of power. That minimum depends directly on the energy cost of ionization. In this paper, approaches to minimize the cost of ionization are examined. It is well understood that the most practical ionization mechanism is through collisions of electrons with neutral species. The cost of ionization as a function of the electron energy indicates that there is more than a two order of magnitude reduction in power required if the plasma is sustained by high energy electrons. These electrons can be supplied from outside the plasma by the use of electron beams, or from within the plasma by short, repetitively-pulsed, very high voltage acceleration of thermal electrons between collisions with neutral gas molecules. Electron beams offer the possibility of sustaining single electrode plasma "fountains" or plasma "thunderstorms," and generate stable, non-filamentary, volume-filling plasmas. Electron beams are approximately a factor of two more efficient than the best that can be achieved with pulse sources, but they must enter the plasma through windows whose losses can easily offset that advantage. High voltage, subnanosecond length pulses at repetition rates of more than 100 KHz avoid the window problem.
AB - The Air Plasma Ramparts MURI goal is to sustain a volume-filling, nonequilibrium plasma with an electron number density of 1013 electrons/cm3 in atmospheric pressure air at temperatures at or below 2000 K, with the minimum expenditure of power. That minimum depends directly on the energy cost of ionization. In this paper, approaches to minimize the cost of ionization are examined. It is well understood that the most practical ionization mechanism is through collisions of electrons with neutral species. The cost of ionization as a function of the electron energy indicates that there is more than a two order of magnitude reduction in power required if the plasma is sustained by high energy electrons. These electrons can be supplied from outside the plasma by the use of electron beams, or from within the plasma by short, repetitively-pulsed, very high voltage acceleration of thermal electrons between collisions with neutral gas molecules. Electron beams offer the possibility of sustaining single electrode plasma "fountains" or plasma "thunderstorms," and generate stable, non-filamentary, volume-filling plasmas. Electron beams are approximately a factor of two more efficient than the best that can be achieved with pulse sources, but they must enter the plasma through windows whose losses can easily offset that advantage. High voltage, subnanosecond length pulses at repetition rates of more than 100 KHz avoid the window problem.
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U2 - 10.1109/PPPS.2001.01002048
DO - 10.1109/PPPS.2001.01002048
M3 - Conference contribution
AN - SCOPUS:84952016742
T3 - PPPS 2001 - Pulsed Power Plasma Science 2001
SP - 285
EP - 288
BT - PPPS 2001 - Pulsed Power Plasma Science 2001
A2 - Reinovsky, Robert
A2 - Newton, Mark
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference, PPPS 2001
Y2 - 17 June 2001 through 22 June 2001
ER -