Design and construction of a bent crystal spectrometer for studying soft X-rays of Sharif Plasma Focus

A soft X-ray spectrometer based on Johann's method and an embedded curved crystal which was designed and fabricated for the Sharif University of Technology's Plasma Focus (SUT-PF) is presented in this paper. Focusing rays with the same wavelength at a point to increase the ray intensity is a reason for choosing the cylindrical curved crystal spectrometer since its performance is inspired by Bragg's law. The optimal conditions for the SUT-PF (pressure and voltage) are determined and examined by a photodiode detector and a pinhole camera before the experiments. Under the optimal discharge condition for soft X-ray generation, the recorded spectral lines on the radiography film and the corresponding atomic transitions are measured and analyzed using a suitable arrangement of the spectrometer and PF device. Experimental results confirm that the wavelength of the emitted soft X-ray from the ionized argon plasma is mainly in the range of 3 to 4 angstrom, where the atomic transition of 1s2-1s2p at the emitted wavelength of 3.943 angstrom has the highest intensity compared to other spectral lines.