Ion Beam Features Produced by Two Plasma Focus Machines Operated With Different Gases

Ion beams emitted from the low-inductance kJ NX2 plasma focus have been numerically characterized and trends of these beams in various gases have been reported. In this paper, the ion beams from high-inductance kJ plasma focus machines AECS PF2 and INTI operated with various gases are studied. The obtained results show that the beam ions mean energy depends on the gas type and increases with increasing ion mass of the gas. It also indicates a higher ion fluence for H2 (4.4 × 10²⁰ ions m^-2), and a very small fluence value for Xe (0.085 × 10²⁰ ions m^-2). The ion number reduces from H₂ (24 × 10¹⁴) to Xe (0.074 × 10¹⁴). The ion current decreases from H₂ (20.5% of the discharge current) to 5.4% for Xe. The beam energy drops from H₂ (0.63% of stored energy E₀) to 0.4% for O₂; however, then increases from Ne to the radiatively-collapsed gases Ar, Kr, and Xe. Argon has the highest damage factor (77 × 10¹⁰ Wm^-2s^0.5), while the lightest gases have the lowest (2-6 × 1010 Wm^-2s^0.5). The magnetic field compressing the pinch is higher for the heavier gases. This paper confirms that the trends of ion beam production with various gases in high-inductance machines are the same as the trends in low-inductance machines.