Backward Raman compression of x-rays in metals and warm dense matters

TL;DR

This paper investigates the discrepancy in Langmuir wave decay rates in metals and dense plasmas, explores stability regimes for Raman scattering, and demonstrates backward Raman compression of x-ray pulses through computational methods.

Contribution

It identifies a regime where backward Raman scattering is unstable and demonstrates x-ray pulse amplification via backward Raman compression computationally.

Findings

Decay rate of Langmuir waves is much higher than Landau damping predictions.

A stable forward Raman and unstable backward Raman regime is identified.

Backward Raman compression can amplify x-ray pulses effectively.

Abstract

Experimentally observed decay rate of the long wavelength Langmuir wave in metals and dense plasmas is orders of magnitude larger than the prediction of the prevalent Landau damping theory. The discrepancy is explored, and the existence of a regime where the forward Raman scattering is stable and the backward Raman scattering is unstable is examined. The amplification of an x-ray pulse in this regime, via the backward Raman compression, is computationally demonstrated, and the optimal pulse duration and intensity is estimated.