Comparison of thermo-luminescent detectors and X-ray vacuum detectors for measurement of X-ray yield from gold plasma produced by a sub-nanosecond Nd:glass laser

Measurement of X-ray flux from laser-produced plasmas has always been important for several applications of the laser-plasma X-ray source. A CaSO4:Dy thermo-luminescent dosimeter (TLD) in powder form has been used in experiments reported in this paper to measure absolute X-ray yield from a gold laser plasma in a spectral region of 0.7–10 keV. The results are compared with indigenously developed X-ray vacuum photodiodes (XVPD). The TLD is a simple and accurate diagnostics for the X-ray measurements in a wide (few eV up to MeV) X-ray spectral region. It is extremely sensitive, capable of measuring an X-ray dose as low as μGy and also has a dynamic range of almost 106, which is several orders of magnitude higher compared to the XVPD. Therefore, TLD is very well suited for integrated X-ray measurements from laser plasmas. Multi-channel arrays of TLD and XVPD are used with various X-ray filters to cover the desired spectral range. A comparative measurement was also carried out between X-ray yield from laser-produced plasma and a conventional X-ray generator operated at low voltage. It was observed that the X-ray dose in laser-produced plasma is almost 109 orders higher than the conventional X-ray generator.