Measurement of Argon Ion Beam and x-ray Energies in a Plasma Focus Discharge

Abstract

We investigated the characteristics of ion beam emission in a small 1.9 kJ Mather-type plasma focus device filled with argon gas, and obtained the energy spectra of argon ion beams using a time-of-flight (TOF) method with a capacitive current monitor and a well-designed Faraday cup. We also observed x-ray emissions, and obtained the time correlation between the x-ray emissions and the ion emissions. The maximum energy of the argon ions was over 800 keV, and the most common ion energy was 200 keV. Ion emission started before the x-ray emission, and was also observed when no x-ray emission was detected; however stronger ion emissions were observed when x-ray emissions were detected. The energy of soft x-rays was determined to be about 2.96 keV of Ar Kα line using a mass absorption method, and hard x-ray emissions of Cu Kα line was also observed. We compare our experimental results with several existing models of the charged particle acceleration in a plasma focus discharge.