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 × 10
²⁰
ions m
^-2
), and a very small fluence value for Xe (0.085 × 10
²⁰
ions m
^-2
). The ion number reduces from H
₂
(24 × 10
¹⁴
) to Xe (0.074 × 10
¹⁴
). The ion current decreases from H
₂
(20.5% of the discharge current) to 5.4% for Xe. The beam energy drops from H
₂
(0.63% of stored energy E
₀
) to 0.4% for O
₂
; however, then increases from Ne to the radiatively-collapsed gases Ar, Kr, and Xe. Argon has the highest damage factor (77 × 10
¹⁰
Wm
^-2
s
^0.5
), while the lightest gases have the lowest (2-6 × 1010 Wm
^-2
s
^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.