Share Email Print
cover

Proceedings Paper

Observations on the ponderomotive force
Author(s): D. A. Burton; R. A. Cairns; B. Ersfeld; A. Noble; S. Yoffe; D. A. Jaroszynski
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper 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.

Paper Details

Date Published: 15 May 2017
PDF: 6 pages
Proc. SPIE 10234, Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources II, 102340G (15 May 2017); doi: 10.1117/12.2270542
Show Author Affiliations
D. A. Burton, Univ. of Lancaster (United Kingdom)
R. A. Cairns, Univ. of St. Andrews (United Kingdom)
B. Ersfeld, Univ. of Strathclyde (United Kingdom)
A. Noble, Univ. of Strathclyde (United Kingdom)
S. Yoffe, Univ. of Strathclyde (United Kingdom)
D. A. Jaroszynski, Univ. of Strathclyde (United Kingdom)


Published in SPIE Proceedings Vol. 10234:
Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources II
Dino A. Jaroszynski, Editor(s)

© SPIE. Terms of Use
Back to Top