Direct-drive cryogenic-target implosion experiments on SGIII prototype laser facility
- Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)
Directly driven cryogenic target implosion experiments are performed on the SGIII prototype laser facility. X-ray pinhole images reveal frozen condensation on the sealing film. The influence of the condensation on the delivery of laser energy to the capsule surface is then quantified experimentally. It is found that, with a carefully chosen pre-pulse duration, the influence can be reduced, and the neutron yield is increased by an order of magnitude. Subsequently, the cryogenic layered capsule and cryogenic gas-filled capsule are imploded using 6.5-kJ laser energy. The implosion performance is characterized by the neutron yield, the 2D self-emission images of the in-flight shell, and the primary proton spectrum. The neutron yield is 2 × 10{sup 7} for the gas-filled capsule and 2.8 × 10{sup 7} for the layered capsule. The 2D self-emission images of the in-flight shell exhibit significant implosion asymmetry. The energy downshift of the proton spectrum is used to infer the areal density. For the gas-filled capsule, the spectrum is downshifted by 0.1 MeV, yielding an areal density of 1–3 mg/cm{sup 2}. For the layered capsule, the spectrum is downshifted by 0.5 MeV, yielding an areal density of 4–6 mg/cm{sup 2}. Improving the implosion symmetry would help to further increase the areal density.
- OSTI ID:
- 22408330
- Journal Information:
- Physics of Plasmas, Vol. 22, Issue 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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