title: Phase mixing of relativistically intense waves in a cold homogeneous plasma.
abstract: We report on spatiotemporal evolution of relativistically intense longitudinal electron plasma waves in a cold homogeneous plasma, using the physically appealing Dawson sheet model. Calculations presented here in the weakly relativistic limit clearly show that under very general initial conditions, a relativistic wave will always phase mix and eventually break at arbitrarily low amplitudes, in a time scale omegapetaumix approximately {3/64(omegape2delta3/c2k2)|Deltak/k|(|1+Deltak/k|)](1+1|1+Deltak/k|)}(-1). We have verified this scaling with respect to amplitude of perturbation delta and width of the spectrum (Deltakk) using numerical simulations. This result may be of relevance to ultrashort, ultraintense laser pulse-plasma interaction experiments where relativistically intense waves are excited.
authors.affiliation: Institute for Plasma Research, Bhat, Gandhinagar 382 428, India. sudip@ipr.res.in
authors.forename: Sudip
authors.initials: S
authors.lastname: Sengupta
authors.forename: Vikrant
authors.initials: V
authors.lastname: Saxena
authors.forename: Predhiman K
authors.initials: PK
authors.lastname: Kaw
authors.forename: Abhijit
authors.initials: A
authors.lastname: Sen
authors.forename: Amita
authors.initials: A
authors.lastname: Das