关键词: Z箍缩/
动态黑腔/
辐射磁流体力学/
冲击波
English Abstract
One-dimensional numerical investigation on the formation of Z-pinch dynamic hohlraum using the code MULTI
Wu Fu-Yuan1,2,Chu Yan-Yun1,
Ye Fan1,
Li Zheng-Hong1,
Yang Jian-Lun1,
Rafael Ramis2,
Wang Zhen1,
Qi Jian-Min1,
Zhou Lin1,
Liang Chuan1
1.Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China;
2.E. T. S. I. Aeronautica y del Espacio, Universidad Politecnica de Madrid, Madrid 28040, Spain
Fund Project:Project supported by the National Natural Science Foundation of China (Grant Nos. 11135007, 11305155), the Spanish Ministerio de Economia y Competitividad (Grant No. ENE2014-54960-R), and the EUROfusion Consortium Project(Grant No. AWP15-ENR-01/CEA-02).Received Date:27 May 2017
Accepted Date:10 July 2017
Published Online:05 November 2017
Abstract:Z-pinch dynamic hohlraum can effectively convert Z-pinch plasma kinetic energy into radiation field energy, which has a potential to implode a pellet filled with deuterium-tritium fuel to fusion conditions when the drive current is sufficiently large. To understand the formation process of Z-pinch dynamic hohlraum on JULONG-I facility with a typical drive current of 8-10 MA, a new radiation magneto-hydrodynamics code is developed based on the program MULTI-IFE. MULTI-IFE is a one-dimensional, two-temperature, multi-group, open-source radiation hydrodynamic code, which is initially designed for laser and heavy ion driven fusion. The original program is upgraded to simulate Z-pinch related experiments by introducing Lorentz force, Joule heating and the evolution of magnetic field into the code. Numerical results suggest that a shock wave and a thermal wave will be launched when the high speed plasma impacts onto the foam converter. The thermal wave propagates much faster than shock wave, making the foam become hot prior to the arrival of shock wave. For the load parameters and drive current of shot 0180, the calculated propagation speed of thermal wave and shock wave are about 36.1 cm/s and 17.6 cm/s, respectively. The shock wave will be reflected when it arrives at the foam center and the speed of reflected shock wave is about 12.9 cm/s. Calculations also indicate that the plastic foam will expand obviously due to the high temperature radiation environment (~30 eV) around it before the collision between tungsten plasma and foam converter. The evolution of radial radiation temperature profile shows that a pair of bright strips pointing to the foam center can be observed by an on-axis streak camera and the radiation temperature in the foam center achieves its highest value when the shock arrives at the axis. A bright emission ring moving towards the foam center can also be observed by an on-axis X-ray frame camera. The best time to capture the bright strips and bright emission rings is before the thermal wave reaches the foam center. Even though some amount of X-ray radiation in the foam is expected to escape from the hohlraum via radiation transport process, simulation results suggest that the tungsten plasma can serve as a good hohlraum wall. The radiation temperature is about 80 eV when the dynamic hohlraum is created and can rise more than 100 eV before the shock arrives at the foam center. Most of the X-rays emitted by the wire-array plasma surface have energies below 1000 eV. In this paper, the physical model of the code MULTI-IFE and the simulation results of array implosions on Saturn facility are presented as well.
Keywords: Z-pinch/
dynamic hohlraum/
radiation magneto-hydrodynamics/
shock
