Effect of atomic number and pressure on plasma pinch properties and characteristic soft x-ray emission in PF1000

Abstract

In this study, the Lee code is used to compute the characteristics soft X-ray yield (Ysxr) production for nitrogen (N2), oxygen (O2), neon (Ne), and argon (Ar) and bremsstrahlung radiation for hydrogen (H2), deuterium (D2), and helium (He) with pressure variation in PF1000 of 2.5 – 2.6 MA for D2. In calculation of characteristic soft X-ray, the corresponding temperature windows of the said gases are set into the code at which they are ionized to their H-like and He-like levels. The focus pinch parameters such as radius ratio (minimum radius of plasma pinch column/anode radius), ion density, specific heat ratio, pinch energy density, self-absorption correction factor and maximum induced voltage are computed at the optimum pressure of each gas. The obtained pinch plasma temperature range (1.2 - 2.2) × 10^6 K of H2, D2, and He is sufficiently high for fully ionized plasmas and the resulting bremsstrahlung radiation (14 J) for He is significantly larger than for H2 (0.26 J) and D2 (0.62 J). The optimum Ysxr of Ne(~9314 J) at 0.51 Torr with pinch energy density (PED) (~26 × 10^8 Jm^-3) is found to be the highest whilst for Ar(~7 J) at 0.019 Torr with (~1.2 × 108 Jm^-3) is the lowest. It is found that the radius ratio (~0.05) of Ne is 3-fold smaller than that (~0.16) in Ar. This enhancement of compression in pinch of Ne increases the ion density significantly by a factor of 253 than in Ar gas. Thus, the results show a strong correlation of plasma pinch properties with Ysxr for various gases