Estimation of the neutron generation from gas puff Z-pinch on Qiang-Guang i facility

Z-pinch using a deuterium gas-puff load has been validated as a plasma neutron source on many accelerators such as Saturn, Z, Angara-5, and S-300. The experimental results on these accelerators show that the production of the neutron can be scaled as Yn∝Im4, where Y_n is the yield and I_m is the peak current of the accelerator, no matter what mechanism is eventually determined to be responsible for generating fusion neutrons. The neutron production on the Qiang-Guang I generator (1.5 MA, 100 ns) is analytically estimated that approximately 4 × 10¹⁰ D-D neutrons would be produced, among which the thermonuclear neutrons is only 7 × 10⁷. The gas puff construction used on Qiang-Guang I is introduced, and the optimum line mass of the D₂ gas is given. The results show that the optimum line mass is approximately 50 μg/cm for the driving current of Qiang-Guang I. The mass density distribution obtained with the classical ballistic-transport model demonstrates that the gas puff forms a hollow gas shell with the length of 2 cm. For D₂ to produce a gas flow with the line mass of 50 μg/cm, the firing time of Qiang-Guang I changes to 250 μs and the absolute pressure of the chamber is increased to 4.2 atm.