English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The influence of finite relaxation times on Thomson scattering fromwarm-dense plasmas is examined within the framework of the average-atomapproximation. Presently most calculations use the collision-free Lindharddielectric function to evaluate the free-electron contribution to the Thomsoncross section. In this work, we use the Mermin dielectric function, whichincludes relaxation time explicitly. The relaxation time is evaluated bytreating the average atom as an impurity in a uniform electron gas and dependscritically on the transport cross section. The calculated relaxation ratesagree well with values inferred from the Ziman formula for the staticconductivity and also with rates inferred from a fit to the frequency-dependentconductivity. Transport cross sections determined by the phase-shift analysisin the average-atom potential are compared with those evaluated in the commonlyused Born approximation. The Born approximation converges to the exact crosssections at high energies; however, differences that occur at low energies leadto corresponding differences in relaxation rates. The relative importance ofincluding relaxation time when modeling X-ray Thomson scattering spectra isexamined by comparing calculations of the free-electron dynamic structurefunction for Thomson scattering using Lindhard and Mermin dielectric functions.Applications are given to warm-dense Be plasmas, with temperatures ranging from2 to 32~eV and densities ranging from 2 to 64~g/cc.

Average-atom treatment of relaxation time in X-ray Thomson scattering from warm-dense matter