Numerical Modeling of Plasma Dynamics and Neutron Generation in Z-pinch at the ANGARA-5-1 Facility

Abstract

Deuterium Z-pinch experimental studies [1] were carried out at the Angara-5-1 facility at a current of 2–2.5 MA with 100 ns rise time. Neutron yield in experiments ranged from 5 × 10¹⁰ to 8 × 10¹¹ neutrons per pulse. In order to explain experimental results, the two-dimensional MHD calculations were performed taking into account the generation of DD-neutrons using thermonuclear and beam-target mechanisms. MHD calculations of pinch dynamics, carried out taking into account the deuterium density distribution in the gas puff, satisfactory agree with voltage measurements. The neutron yield in the calculations ranges from 4 × 10¹⁰ to 1.5 × 10¹¹ depending on the deuterium density and the time delay between the start of gas puff and the moment of generator start-up. The energy of accelerated deuterons, which lead to neutron generation in the beam-target mechanism, is calculated to be from 55 to 900 keV, which is in satisfactory agreement with the estimates obtained [1]. An important difference between neutron generation in a fast gas Z-pinch and neutron generation in a dense plasma focus is that the contributions of thermonuclear and beam-target mechanisms to neutron generation in a fast gas Z-pinch are comparable, whereas in a dense plasma focus the main neutron generation mechanism is the beam-target mechanism.