Article thumbnail

PLASMA-PHYSICS-04 Optimization of the hohlraum wall composition

By E. Yu. Arapova, M. A. Barinov, M. A. Vronskii, G. V. Dolgoleva and V. F. Yermolovich


Experimental investigations on the conversion of Nd-laser radiation (λ = 532 nm, intensity 10 13 W/cm 2) into X-rays by irradiating gold/copper alloys have shown a dependence on the atomic percentage of gold in the alloys [1, 2]. The X-ray yield in the photon energy region up to 1 keV reaches the maximum when the alloy contains 43 % of gold. For harder X-rays above 1 keV the yield decreases drastically with a higher percentage of gold in the alloy. Adding 12 % of gold into the copper of the originally investigated alloy results in a decrease by a factor of 2.1 for X-ray’s above 1 keV. The one-dimensional code SND [3] is developed for calculations of two temperature gas dynamics of plasma expansion and includes the radiation transport in a diffusion approximation. The wavelength dependent radiation diffusion in materials was used to determine the conversion of laser radiation into X-rays in AuCu alloys by variation of the gold content. The needed spectral opacities were obtained using the THERMOS code [4], which calculates spectral absorption ratios on the basis of the average atom model in the modified Hartree–Fock-Slater approximation. Fig.1 shows the curves calculated for the X-ray flux (energies up to 1 keV) emitted from a Au0.43Cu0.57- alloy at a laser intensity of 10 13 W/cm 2. For a part of the X-ray spectrum the maximum yield of the radiation from the Au/Cu-alloy is higher than that from laser irradiated pure gold- or copper-targets. For example the X-ray´s yield from the Au0.43Cu0.57- alloy at 0.15 keV, 0.3 keV and between 0.7 – 1 keV is higher than the yield from the pure gold or copper, irradiated with the same laser parameters. For the X-ray energies higher than 1 keV a significant decrease in the X-ray yield is observed for alloys containing more gold, see Fig. 2. Figure 2: The calculated ratios of fluxes for the AuxCu1-xand for the pure Au in the photon energy range of 1.15-1.6 keV: S ( Au Cu) / S ( Au) [1.15, 1.6] keV x 1 − x [1.15

Year: 2012
OAI identifier: oai:CiteSeerX.psu:
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.