Chunk mixing implosion experiments using deuterated foam capsules with gold dopant

To study the effects of chunk mixing, the implosion experiments using capsules filled with deuterated foam (CDF capsule) were carried out on the Shenguang laser facility. Three types of the CDF capsules, namely the capsules without Au dopant, with micrometer Au dopant, and with atomic Au dopant, were used in the experiments. The neutron yields, the size, and the emission intensity of the hotspots were measured. The CDF capsules without Au dopant produced the highest neutron yield and the largest hotspot size at the time of peak emission. The capsules with micrometer or atomic Au dopant showed similar reduced neutron yield and hotspot size. The time-resolved hotspot emissions showed different behaviors between different capsules. One-dimensional simulations were carried out to understand the implosion dynamics of the CDF capsule without Au dopant, and to provide the thermodynamic conditions that the Au dopant would experience during the implosion. The effects of Au dopant were then discussed qualitatively.

Figure 1

Schematic of reference target (a), type I, target with micrometer Au dopant (b), type II, and target with atomic Au dopant (c), type III.

Figure 2

X-ray images of deuterated foam samples doped with micrometer Au (a) and atomic Au (b).

Figure 3

Measured neutron yields for different types of capsules.

Figure 4

Intensity normalized hotspot images at x-ray bang time for (a) type-I capsule, (b) type-II capsule, and (c) type-III capsule

Figure 5

Intensity normalized hotspot images at 160 ps before x-ray bang time for (a) type-I capsule, (b) type-II capsule, and (c) type-III capsule.

Figure 6

Typical streaked spectrum (a) and time-resolved implosion emission (b)

Figure 7

Spectra for different capsules at different times.

Figure 8

Normalized neutron yield varies with Au weight fraction (wt%). The black lines are the calculations with (black solid) and without (black dashed) ten times reduction of Au opacity. The measured neutron yield for the type-II capsule is the blue solid line. The intersection between the blue solid line and the black solid line corresponds to the effective weight fraction for the type-II capsule.