Effects of polarization direction on laser-assisted free-free scattering
Author(s)
deHarak, BA
Kim, BN
Weaver, CM
Martin, NLS
Siavashpouri, Mahsa
Nosarzewski, Benjamin
Griffith University Author(s)
Year published
2016
Metadata
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This work will detail the effects of laser polarization direction (relative to the momentum transfer direction) on laser-assisted free–free scattering. Such processes play a role in the gas breakdown that occurs in electric discharges as well as providing a method for the laser heating of a plasma (Musa et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 175201, Mason 1993 Rep. Prog. Phys. 56 1275). Experimental results will be presented for electron-helium scattering in the presence of an Nd:YAG laser field ($h\nu =1.17$ eV) where the polarization direction was varied in a plane that is perpendicular to the scattering plane. To ...
View more >This work will detail the effects of laser polarization direction (relative to the momentum transfer direction) on laser-assisted free–free scattering. Such processes play a role in the gas breakdown that occurs in electric discharges as well as providing a method for the laser heating of a plasma (Musa et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 175201, Mason 1993 Rep. Prog. Phys. 56 1275). Experimental results will be presented for electron-helium scattering in the presence of an Nd:YAG laser field ($h\nu =1.17$ eV) where the polarization direction was varied in a plane that is perpendicular to the scattering plane. To date, all of our experimental results are well described by the Kroll–Watson approximation (KWA) (Kroll and Watson 1973 Phys. Rev. A 8 804). The good agreement between our experiments and calculations using the KWA includes the case where the polarization is perpendicular to the momentum transfer direction, for which the KWA predicts vanishing cross section; other workers have found that the KWA tends to be inaccurate for cases where it predicts small cross sections (e.g. Musa et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 175201). We also present simulations of the effects that multiple scattering might have on experimental measurements. In particular, we examine conditions that are expected to be similar to those of the experiments reported by Wallbank and Holmes (Wallbank and Holmes 1993 Phys. Rev. A 48 R2515).
View less >
View more >This work will detail the effects of laser polarization direction (relative to the momentum transfer direction) on laser-assisted free–free scattering. Such processes play a role in the gas breakdown that occurs in electric discharges as well as providing a method for the laser heating of a plasma (Musa et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 175201, Mason 1993 Rep. Prog. Phys. 56 1275). Experimental results will be presented for electron-helium scattering in the presence of an Nd:YAG laser field ($h\nu =1.17$ eV) where the polarization direction was varied in a plane that is perpendicular to the scattering plane. To date, all of our experimental results are well described by the Kroll–Watson approximation (KWA) (Kroll and Watson 1973 Phys. Rev. A 8 804). The good agreement between our experiments and calculations using the KWA includes the case where the polarization is perpendicular to the momentum transfer direction, for which the KWA predicts vanishing cross section; other workers have found that the KWA tends to be inaccurate for cases where it predicts small cross sections (e.g. Musa et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 175201). We also present simulations of the effects that multiple scattering might have on experimental measurements. In particular, we examine conditions that are expected to be similar to those of the experiments reported by Wallbank and Holmes (Wallbank and Holmes 1993 Phys. Rev. A 48 R2515).
View less >
Journal Title
Plasma Sources Science and Technology
Volume
25
Issue
3
Subject
Atomic, molecular and optical physics
Science & Technology
Physical Sciences
Physics, Fluids & Plasmas
Physics
laser-assisted electron scattering