Development of a powerful X-ray generator with a small spot-size option at ISAS X-ray beamline facility

摘要

We present the measurements of the spot size of a powerful X-ray generator at an ISAS 30 m X-ray beamline facility. A parallel light is ideal to measure the point spread function of an X-ray telescope. However, we cannot make purely parallel light because we have to use an X-ray source with a finite size at a finite distance in a ground facility. Therefore a powerful X-ray generator with a small spot size is strongly favored in terms of the measurements of X-ray telescopes. We developed an X-ray generator with a small spot size by collaborating with a manufacturer Rigaku corporation. Using a pinhole technique, we found that spot sizes of the normal and fine filament options are 0.76 mm and 0.25 mm in Half Power Width (HPW) for Cu-K line at 8.0 keV, respectively. The spot sizes for Al-K line at 1.5 keV are 0.50 mm and 0.22 mm (HPW), respectively. When we supplied a bias voltage for the fine filaments, the spot size becomes as small as 0.25 mm for Cu-K line and 0.22 mm for Al-K line. The sizes of the fine filament are equivalent to the angular uncertainties of 2 arcsecs for the measurements of the point spread function of an X-ray telescope.