The delayed absorption of microwaves due to electron thermalization in nanosecond pulse irradiated N2, He, and Ar at atmospheric pressure

The absorption of microwaves in pulse irradiated C2H6 (ethane), N2, He, and Ar at atmospheric pressure has been investigated on a nanosecond timescale. In the case of C2H6, a time of less than 1 nsec following the pulse is required for the absorption signal to reach a time independent plateau value. For N2, He, and Ar, a considerable delay in the development of the absorption signal is observed. This increase in absorption coefficient over 20, 50, and 300 nsec in the case of N2, He, and Ar, respectively, is attributed to a time dependence of the electron collision frequency resulting from post‐pulse thermalization of the electron energy. Using momentum transfer collision frequency data from swarm studies, the time dependence of the electron energy has been derived and is discussed in terms of the energy exchange rate coefficient Ku, defined by −d?/dt=Ku [?−(3/2) kT]N. For N2, Ku is found to be almost independent of electron energy over the range kTe=0.03–0.7 eV and has a mean value of 1.55×10−11 cm3 sec−1...

[1]  J. Warman,et al.  An investigation of electron thermalization in irradiated gases using CCl4 as an electron energy probe , 1975 .

[2]  N. Adams,et al.  Observations of electron temperature relaxation rates in rare gas afterglow plasmas , 1974 .

[3]  J. Warman,et al.  The detection of electrons in pulse irradiated liquid hydrocarbons by microwave absorption , 1973 .

[4]  Y. Itikawa.  Effective collision frequency of electrons in gases , 1973 .

[5]  L. H. Luthjens,et al.  Wide Band Reversing Transformer as Automatic Backing‐off Device in Nanosecond Absorption Spectrophotometry , 1973 .

[6]  R. W. Fessenden,et al.  On the pressure dependence of electron attachment to O2 , 1971 .

[7]  L. Christophorou,et al.  Atomic and Molecular Radiation Physics , 1971 .

[8]  M. Elford,et al.  The Momentum Transfer Cross Section for Electrons in Helium Derived from Drift Velocities at 77°K , 1970 .

[9]  A. Phelps.  ROTATIONAL AND VIBRATIONAL EXCITATION OF MOLECULES BY LOW-ENERGY ELECTRONS. , 1968 .

[10]  R. W. Fessenden,et al.  THE STUDY OF ELECTRON DECAY IN PULSE-IRRADIATED GASES BY A MICROWAVE TECHNIQUE. , 1968 .

[11]  C. G. Montgomery,et al.  Principles of Microwave Circuits , 1965 .

[12]  A. V. Phelps,et al.  MOMENTUM TRANSFER CROSS SECTIONS FOR SLOW ELECTRONS IN HE, AR, KR, AND XE FROM TRANSPORT COEFFICIENTS, , 1964 .

[13]  A. Phelps,et al.  DETERMINATION OF MOMENTUM TRANSFER AND INELASTIC COLLISION CROSS SECTIONS FOR ELECTRONS IN NITROGEN USING TRANSPORT COEFFICIENTS. , 1964 .

[14]  A. Phelps,et al.  Drift Velocities of Slow Electrons in Helium, Neon, Argon, Hydrogen, and Nitrogen , 1961 .

[15]  S. Brown,et al.  Microwave Conductivity of an Ionized Decaying Plasma at Low Pressures , 1957 .

[16]  P. Rosen.  ELECTROMAGNETIC WAVES IN AN IONIZED GAS , 1956 .

[17]  W. P. Jesse,et al.  IONIZATION BY ALPHA PARTICLES IN MIXTURES OF GASES , 1955 .

[18]  O. T. Fundingsland,et al.  MICROWAVE DETERMINATION OF THE PROBABILITY OF COLLISION FOR SLOW ELECTRONS IN GASES. Technical Report No. 211 , 1951 .

[19]  M. A. Biondi.  Measurement of the Electron Density in Ionized Gases by Microwave Techniques , 1951 .

[20]  S. Brown,et al.  Measurements of ambipoloar diffusion in helium , 1949 .

[21]  H. Margenau.  Conduction and Dispersion of Ionized Gases at High Frequencies , 1946 .