A novel multi-collimator using BP-1 glass and an application for X-ray CCDs

Charge-coupled devices (CCDs) are widely used in X-ray astronomy as a focal plane detector for X-rays up to 10  keV. For future X-ray space missions, thick CCDs are being developed to improve the detection efficiency of high energy X-rays beyond 10 keV. We propose a new method to produce a novel multi-collimator using a barium phosphate glass, BP-1, which was originally developed as a solid state track detector. The BP-1 collimator allows the realization of small through-holes, several hundred nano-meters in radius. We performed the first experiment of this project in which a xenon beam of 80MeV/u was used to irradiate the 1.3 mm-thick-BP-1 glass. After an etching process, we obtained the first prototype BP-1 collimator. There were a large number of tapered pinholes which are randomly distributed and with extremely high aspect ratio. Taking X-ray photographs demonstrated that the first prototype has a capability of fine collimation for X-rays up to 20 keV.