A magnetic spectrometer positioned on the axis of a 3 kJ plasma focus devicehas been used to measure energy spectra of deuterons emitted from the pinchregion of the focus, while an indium activation detector was employed tomeasure the associated neutron flux. Solid-state nuclear track detectors(PM-355) were used in the focal plane of the spectrometer to detect theanalysed ions, with multiple spectra being recorded on each detector. Anautomated track counting system has been developed to read the spectralinformation from the detectors, which has facilitated the analysis of a fargreater number of energy spectra, with greater accuracy, than has beenpossible in previous work. This automated system comprises an opticalmicroscope with CCD camera, a motorized microscope stage, and image processingand control software. The experimental results show that the deuterons emittedfrom the pinch region have a continuous spectrum of energies which follow theempirical relationship dN/dE∝E-n, where n is typically in the range 6-7. A clearcorrelation between the measured deuteron energy spectra and neutron flux isobserved at each of three working gas pressures investigated.
Particle beams generated by a 6–12.5 kJ dense plasma focus