Characterisation of HEXITECMHz - A 1 MHz continuous frame rate spectroscopic X-ray imaging detector system

Abstract

Spectroscopic X-ray imaging techniques including Compton X-ray Imaging, X-ray Fluorescence Imaging and Hyperspectral X-ray Tomography require energy-resolving detectors capable of operating at high incident X-ray fluxes to make time resolved measurements. HEXITECMHz, operates at a continuous 1 MHz frame rate and can make fully spectroscopic measurements at >106 ph s−1 mm−2. This is enabled by an integrating Front End, in-pixel digitisation and high-speed serialisers. A 300 μm thick p-type Si HEXITECMHz detector was characterised on the B16 Test Beamline at the Diamond Light Source and are the first measurements taken at a 1 MHz frame rate. At 10 keV and 15 keV) the device displayed average FWHM of 656 eV and 682 eV respectively, with minimal changes in spectroscopic performance over ∼8 h. Analysis of charge-sharing events show low charge loss and a linear energy-signal response. Higher-flux measurements illustrated the capability of the ASIC to operate as a photon-counting device.