skip to main content


Title: Relativistic ponderomotive Hamiltonian of a Dirac particle in a vacuum laser field

Here, we report a point-particle ponderomotive model of a Dirac electron oscillating in a high-frequency field. Starting from the Dirac Lagrangian density, we derive a reduced phase-space Lagrangian that describes the relativistic time-averaged dynamics of such a particle in a geometrical-optics laser pulse propagating in vacuum. The pulse is allowed to have an arbitrarily large amplitude provided that radiation damping and pair production are negligible. The model captures the Bargmann-Michel-Telegdi (BMT) spin dynamics, the Stern-Gerlach spin-orbital coupling, the conventional ponderomotive forces, and the interaction with large-scale background fields (if any). Agreement with the BMT spin precession equation is shown numerically. The commonly known theory in which ponderomotive effects are incorporated in the particle effective mass is reproduced as a special case when the spin-orbital coupling is negligible. This model could be useful for studying laser-plasma interactions in relativistic spin-1/2 plasmas.
 [1] ;  [1] ;  [1]
  1. Princeton Univ., Princeton, NJ (United States). Dept. of Astrophysical Sciences
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1050-2947; PLRAAN
Grant/Contract Number:
DE274-FG52-08NA28553; AC02-09CH11466; HDTRA1-11-1-0037; 32-CFR-168a
Accepted Manuscript
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 92; Journal Issue: 6; Journal ID: ISSN 1050-2947
American Physical Society (APS)
Research Org:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY Hamiltonian; laser-plasma interactions; nonlinear theories; ponderomotive force