Breakthrough 4π helium ion energy spatial distribution determination in plasma focus space by Sohrabi mega-size panorama cylindrical ion image detector

Abstract

Recently Sohrabi theorized and discovered that ions in plasma focus devices (PFD) are emitted in 4π ion space instead of within small solid angle above anode, as commonly believed. Ion energies are commonly determined by others at single points above or around anode top. In this study, He ion energy distributions were determined in 4π PFD space applying Sohrabi mega-size panorama cylindrical polycarbonate ion image detectors pre-etched by surface layer removal (SLR) process before electrochemical etching. The SLR is pre-etching process which remove certain thickness of detector surface. Results show that track density versus layer thickness removed has saturation plateau corresponding to countable track density which is equal to penetration range of “minimum detected energy” in the detector. Also, thickness in which track density approaches zero is equal to penetration range of “maximum detected energy” in detector. At different cylindrical detector heights studied, corresponding minimum ion energies (7.0 to 328 keV) and maximum ion energies (70 to 640 keV) and for top cylinder base at different angles minimum energies (57 to 535 keV) and maximum energies (135 to 640 keV) were determined. The novel methods applied proved quite efficient for determination of He ion energies in 4π PFD ion space.