Observations on the ponderomotive force

Burton, David Antony and Cairns, R. A. and Ersfeld, B. and Noble, A. and Yoffe, S. R. and Jaroszynski, D. A. (2017) Observations on the ponderomotive force. Proceedings of SPIE, 10234. ISSN 0277-786X

[img]
Preview
PDF (Burton_Cairns_Ersfeld_Noble_Yoffe_Jaroszynski_SPIE_2017)
Burton_Cairns_Ersfeld_Noble_Yoffe_Jaroszynski_SPIE_2017.pdf - Accepted Version
Available under License Creative Commons Attribution.

Download (219kB)

Abstract

The ponderomotive force is an important concept in plasma physics and, in particular, plays an important role in many aspects of the theory of laser plasma interactions including current concerns like wakefield acceleration and Raman amplification. The most familiar form of this gives a force on a charged particle that is proportional to the slowly varying gradient of the intensity of a high frequency electromagnetic field and directed down the intensity gradiant. For a field amplitude simply oscillating in time there is a simple derivation of this formula, but in the more general case of a travelling wave the problem is more difficult. Over the years there has been much work on this using Hamiltonian or Lagrangian averaging techniques, but little or no investigation of how well these theories work. Here we look at the very basic problem of a particle entering a region with a monotonically increasing electrostatic field amplitude and being reflected. We show that the equation of motion derived from a widely quoted ponderomotive potential only agrees with the numerically computed orbit within a restricted parameter range and that outside this range it shows features which are inconsistent with any ponderomotive potential quadratic in the field amplitude. Since the ponderomotive force plays a fundamental role in a variety of problems in plasma physics we think that it is important to point out that even in the simplest of configurations standard theories may not be accurate.

Item Type:
Journal Article
Journal or Publication Title:
Proceedings of SPIE
Additional Information:
D. A. Burton ; R. A. Cairns ; B. Ersfeld ; A. Noble ; S. Yoffe ; D. A. Jaroszynski; Observations on the ponderomotive force . Proc. SPIE 10234, Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources II, 102340G (May 15, 2017); doi:10.1117/12.2270542. Copyright 2017 Society of Photo Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, or modification of the contents of the publication are prohibited.
ID Code:
86595
Deposited By:
Deposited On:
05 Jun 2017 13:04
Refereed?:
Yes
Published?:
Published
Last Modified:
29 Mar 2020 05:15