Soft X-ray analysis of a dense plasma focus

A two channel soft x-ray spectrometer has been constructed and operated to study the production of x rays by a 12.5 kJ dense plasma focus (DPF). The spectrometer consists of three pin diode detectors filtered by thin metal foils, housed in a long evacuated and electrically insulated aiming tube. Gas mixtures of deuterium with small fractions of neon and nitrogen are being studied. It has been determined that the predominant x-ray emission mechanisms at pinch time for these mixtures is line radiation from the neon and nitrogen fractions. The x-ray spectrometer, using a matched set of filters (Ti, Fe, Cu), can effectively separate the radiation produced by each of the two gas species. A comparison of the magnitudes of these two emissions with theoretically expected values then yields information about the state of the plasma: its temperature and, if absolute measurements are possible, its density. An updated computer model has been developed to analyze the experimental results. The results are discussed