Matter and Radiation at Extremes, 2018, 3 (5): 248, Published Online: Mar. 14, 2019
Numerical studies on the radiation uniformity of Z-pinch dynamic hohlraum
Abstract
Radiation uniformity is important for Z-pinch dynamic hohlraum driven fusion. In order to understand the radiation uniformity of Z-pinch dynamic hohlraum, the code MULTI-2D with a new developed magnetic field package is employed to investigate the related physical processes on Julong-I facility with drive current about 7e8 MA. Numerical simulations suggest that Z-pinch dynamic hohlraum with radiation temperature more than 100 eV can be created on Julong-I facility. Although some X-rays can escape out of the hohlraum from Z-pinch plasma and electrodes, the radiation field near the foam center is quite uniform after a transition time. For the load parameters used in this paper, the transition time for the thermal wave transports from r = 1 mm to r = 0 mm is about 2.0 ns. Implosion of a testing pellet driven by cylindrical dynamic hohlraum shows that symmetrical implosion is hard to achieve due to the relatively slow propagation speed of thermal wave and the compression of cylindrical shock in the foam. With the help of quasi-spherical implosion, the hohlraum radiation uniformity and corresponding pellet implosion symmetry can be significantly improved thanks to the shape modulation of thermal wave front and shock wave front.
Fuyuan Wu, Yanyun Chu, Rafael Ramis , Zhenghong Li, Yanyun Ma, Jianlun Yang, Zhen Wang, Fan Ye, Zhanchang Huang, Jianmin Qi, Lin Zhou, Chuan Liang, Shijia Chen, Zheyi Ge, Xiaohu Yang, Shangwu Wang. Numerical studies on the radiation uniformity of Z-pinch dynamic hohlraum[J]. Matter and Radiation at Extremes, 2018, 3(5): 248.