Two-dimensional simulations of radiation production from stagnating compact toroids

The stagnation of a high Z, high velocity compact toroidal plasma against a stationary object has been shown computationally to be an efficient radiation source. A numerical parameter study has been carried out examining the influence of various prestagnation properties on radiation production. In particular, variations in initial values of ring mass, velocity, magnetic field strength have been investigated and will be reported. The simulations of the stagnation process are being performed using the 2 1/2-dimensional magnetohydrodynamic code MACH2. The radiation field is treated using a flux-limited nonequilibrium radiation diffusion model and the material properties are given from an LTE description of the plasma. All three components of the magnetic field and the velocity are maintained in the calculations. The toroid is assumed to stagnate against a wall, and internal wall effects are neglected. For a 10 mg., nominally 1 cm in diameter compact toroid at a velocity of 100 cm/μs, or a directed kinetic energy of 5 MJ, calculations reveal 4.6 MJ of radiation emitted over a 10 ns period. Simulations also indicate that a three temperature treatment is appropriate for the physical regime used in these calculations. Results will be presented which show that the prestagnation magnetic field, toroid mass, and toroid velocity affect the conversion efficiency of kinetic energy into internal energy and radiation output