On the relationship between neutron yield and deuteron spectra in a small plasma focus device

Deuteron energy spectra emitted from the pinch region of a 3 kJ plasma focus devices at three pressure values (3.5, 4.5 and 4.5 mbar) were investigated using a magnetic spectrometer placed on the forward axis of the device. The ions were detected using a solid state material (PM 355) placed in the focal plane of the spectrometer. The spectral information was inferred using a fully automated track counting systems. Simultaneously, the plasma focus neutron yield was measured by means of an indium foil activation detector. A magnetic spectrometer and an automated scanning system were used to obtain spectra for more than 200 discharges for deuterium gas pressures of 4.0 mbar. The results show that there is a clear correlation between the measured deuteron energy spectra and the neutron yield at each of three working gas pressures investigated. (authors)