skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Exact evaluation of the quadratic longitudinal response function for an unmagnetized Maxwellian plasma

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4737603· OSTI ID:22072551
; ;  [1];  [2]
  1. School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)
  2. Defence Science and Technology Organisation, P.O. Box 1500, Edinburgh, SA 5111 (Australia)

The quadratic longitudinal response function describes the second-order nonlinear response of a plasma to electrostatic wave fields. An explicit expression for this function in the weak-turbulence regime requires the evaluation of velocity-space integrals involving the velocity distribution function and various resonant denominators. Previous calculations of the quadratic longitudinal response function were performed by approximating the resonant denominators to facilitate the integration. Here, we evaluate these integrals exactly for a non-relativistic collisionless unmagnetized isotropic Maxwellian plasma in terms of generalized plasma dispersion functions, and correct certain aspects of expressions previously derived for these functions. We show that in the appropriate limits the exact expression reduces to the approximate form used for interactions between two fast waves and one slow wave, such as the electrostatic decay of Langmuir waves into Langmuir waves and ion sound waves, and the scattering of Langmuir waves off thermal ions.

OSTI ID:
22072551
Journal Information:
Physics of Plasmas, Vol. 19, Issue 7; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English