Optimization of tungsten-doped high density carbon target in inertial confinement fusion

Tungsten(W)-doped high density carbon(HDC) target is a promising design for ignition target in inertial confinement fusion (ICF). The influence of silicon(Si) and tungsten(W) on transmission of M-band X-ray has been studied by experiment. With a radiation temperature of ∼ 200eV , the transmitted M-band X-ray(1.6-4.4keV) flux and spectrum of Si or W-buried HDC sample were measured by M-XRDs and TGS, respectively. The thin layer of Si or W was buried at two different depths(2.1µm and 11µm). Results show that M-band transmission flux of Si-buried HDC sample decreases with buried depth(bd). However bd does not influence that of W-buried HDC sample. The one-dimensional simulation result is consistent with the experimental result. In the 1D simulation, the Au M-band(2-5keV) transmission flux of Si-buried HDC also decreases with bd. However Au M-band transmission flux of W-buried HDC increases at first and then decreases. This is mainly due to the different characteristics of Si and W opacity. Especially as the peak radiation temperature reaches 260eV, W can still absorb the M-band X-ray efficiently as it is buried near the radiation source. Based on these studies, optimized W-doped HDC target with low doped fraction and mass has been proposed in this paper.