Collective Thomson scattering from high-temperature high-density plasmas revisited

Abstract

The theory of Thomson scattering from high-temperature high-density plasmas is revisited from the view point of plasma fluctuation theory. Three subtle effects are addressed with a unified theory. The first is the correction of the first order of v/c, where v is the particle velocity and c is the light speed, the second is the plasma dielectric effect, and the third is the finite scattering volume effect. When the plasma density is high, the first effect is very significant in inferring plasma parameters from the scattering spectra off electron plasma waves. The second is also be notable but less significant. When the size of the scattering volume is much larger than the probe wavelength, the third is negligible.

Relativistic correction of (v/c)2to the collective Thomson scattering for high-temperature high-density plasma

“…The theories of Thomson scattering are thus developed to include various effects that may have important effects on the dynamic form factor S(k, ω), such as the electron-positron plasma, [12] the super-Gaussian electron velocity distribution due to the strong inverse bremsstrahlung absorption, [13−14] the frequent Coulomb collisions [15,16] and the plasma inhomogeneity. [17,18] The scattering spectra from the thermal electron plasma waves, which allow the direct measurement of the electron density and the temperature, were also successfully detected by Glenzer et al [6] Noticing that the plasma temperature was rather high in that experiment and that the differential frequency ω was no longer negligible in comparison with the probe frequency ω 0 , we revisited the first order correction of v/c (where v and c are the electron and the light speed, respectively) to the scattering power spectrum [19] and obtained the same result as that presented by Sheffield, [2] d 2 P dω s dΩ = r 2 e I 0 V s n e (e 0 ×n s ) 2 S(k, ω)…”

“…In the wave zone, the spectral energy emitted from N accelerated electrons into the solid angle dΩ is approximately given by [19]…”

“…With the inclusion of the first order of v/c, we find that not only the intensity but also the spectral profile of the scattering light of the electron plasma waves changes significantly. [19] With Eq. ( 6), the inferred electron temperature from the scattering spectra in Ref.…”

“…(1). [19] With the inclusion of the dependence of wave number on the plasma density, the differential wave vector becomes a little smaller, leading to a smaller wavelength of the resonance peak of the scattering spectrum. [19] As indicated in Eq.…”

“…[19] With the inclusion of the dependence of wave number on the plasma density, the differential wave vector becomes a little smaller, leading to a smaller wavelength of the resonance peak of the scattering spectrum. [19] As indicated in Eq. ( 6), the correction term of 2ω/ω 0 can become of order 1 when the light scattering from the electron plasma waves is detected.…”