Anomalous neutron yield in indirect-drive inertial-confinement-fusion due to the formation of collisionless shocks in the corona

作者：Zhang, Wen-Shuai; Cai, Hong-Bo^*; Shan, Lian-Qiang; Zhang, Hua-Sen; Gu, Yu-Qiu; Zhu, Shao-Ping

来源：Nuclear Fusion, 2017, 57(6): 066012.

DOI：10.1088/1741-4326/aa686c

• inertial confiement fusion
• collisionless shock wave
• anomalous neutron yield
• fast ignition

Observations of anomalous neutron yield in the indirect-drive inertial confinement fusion implosion experiments conducted at SG-III prototype and SG-II upgrade laser facilities are interpreted. The anomalous mechanism results in a neutron yield which is 100-times higher than that predicted by 1D radiation-hydrodynamic simulations. 2D radiation-hydrodynamic simulations show that the supersonic, radially directed gold (Au) plasma jets arising from the laser-hohlraum interactions can collide with the carbon-deuterium (CD) corona plasma of the compressed pellet. It is found that in the interaction front of the high-Z jet with the low-Z corona, with low density similar to 10(20) cm(-3) and high temperature similar to keV, kinetic effects become important. Particle-in-cell simulations indicate that an electrostatic shock wave can be driven when the high-temperature Au jet expands into the low-temperature CD corona. Deuterium ions with an amount of similar to 10(15) can be accelerated to similar to 25 keV by the collisionless shock wave, thus causing efficient neutron productions though the beam-target method by stopping these energetic ions in the corona. The evaluated neutron yield is consistent with the experiments conducted at SG laser facilities.

• 出版日期2017-6
• 单位北京应用物理与计算数学研究所; 中国工程物理研究院激光聚变研究中心; 北京大学; 上海交通大学; 中国工程物理研究院