Performance measurements from LYSO scintillators coupled to a CMOS position sensitive SSPM detector

摘要

We have designed a 5x5 mm2 position sensitive solid-state photomultiplier (PS-SSPM) using a complementary metal-oxide-semiconductor (CMOS) process that provides imaging capability on the micro-pixel level. The PS-SSPM has 11,664 micro-pixels total, with each having an active area and micro-pixel pitch of 30 x 30 um2 and 44.3 urn, respectively. The PS-SSPM was then examined for its performance characteristics such as its energy and spatial resolution, and LYSO scintillator array imaging capabilities. When coupled to 5 x 5 x 3 mm~3 LYSO, the energy resolution at 511 keV (~(22)Na) was measured as a function of bias, and corrected for the PS-SSPM non-linear output. The resolution is 14% (FWHM) at 511 keV with 30 V bias. The LYSO coincidence timing resolution was 9.4 ns (FWHM) at 511 keV. Spatial resolution studies were conducted using a focused (～30μm beam spot diameter) pulsed 635 nm diode laser. Scintillator array imaging studies were conducted at 511 keV using a 6 x 6 LYSO array, having 500 um pixels (530 μm pitch) and 5 mm tall.