Energy- and time-resolved measurements of fast ions emitted from Plasma-Focus discharges, by means of a Thomson spectrometer

The paper presents results of time-resolved measurements of fast deuterons emitted from high-current discharges of the Plasma-Focus (PF) type. The measurements were performed within a modified DPF-1000U facility, which is operated at the IFPiLM in Warsaw, Poland. The device was equipped with a fast-acting gas valve, placed inside the inner electrode and oriented along the z-axis. The valve could inject a small volume of a chosen gas in front of this electrode. The PF discharges were initiated at the initial deuterium pressure equal 1.6 or 2 hPa, with or without the use of the gas-puffing. Such discharges emitted intense beams of accelerated primary ions and X-ray pulses as well as products of nuclear fusion reactions.

The reported measurements of the fast ion beams were performed by means of a Thomson-type spectrometer located at a chosen distance at the z-axis and equipped with miniature scintillation detectors. These detectors were placed at different points upon the deuteron parabola, which corresponded to determined energy values. The applied configuration of the detectors allowed us to determine instants of the ion emission (using a TOF technique) and to compare them with instants of the X-ray emission. The collected data delivered important information about emission characteristics of the modified DPF-1000U facility.