Sep 12 – 17, 2021
University of Birmingham
Europe/London timezone

Spectroscopic X-ray Imaging at MHz Frame Rates – The HEXITEC$_{MHz}$ ASIC

Sep 15, 2021, 5:45 PM
Teaching and Learning Building (University of Birmingham)

Teaching and Learning Building

University of Birmingham

Edgbaston Campus University of Birmingham B15 2TT UK
talk X-ray and Gamma Ray Detectors X-ray and Gamma Ray Detectors 2


Lawrence Jones (UKRI STFC)


The HEXITEC$_{MHz}$ ASIC has been developed for the HEXITEC$_{MHz}$ Detector System, to deliver spectroscopic x-ray imaging at frame rates up to 1MHz for future high-flux-rate applications. Optimised for sensing electron signals from detector materials such as CdTe, CZT, GaAs, Ge and p-type silicon detectors, the design has an array of 80x80 pixels on a pitch of 250$\mu$m, with each pixel capable of measuring single x-ray photons up to energies of 200keV, with a resolution of 1keV FWHM.

Further improvements in the spatial and spectroscopic resolution are possible due to the pixel’s ability to simultaneously sense positive signals up to 20keV induced by internal weighting potential effects from electron signals on neighbouring pixels.

A count rate limit of around 10$^{6}$ photons s$^{-1}$ mm$^{-2}$ is achieved by converting the signals from all pixels every 1$\mu$s using 12-bit time-to-digital converters – an improvement of two orders of magnitude over previous HEXITEC ASICs. To save power, each converter is shared between groups of eight pixels.

Each 76.8kbit data frame is Aurora 64b/66b encoded and serialised over 20 lanes of differential CML, all operating in parallel at 4.1Gbps.

In this paper, we present details of the design, and possibly preliminary test results from the ASIC.

Your name Lawrence Jones
Institute UKRI STFC
Nationality British
Title Mr

Primary authors

Adam Barcock (UKRI STFC) Lawrence Jones (UKRI STFC) Chris Lyford (UKRI STFC) David Sole (UKRI STFC) Ivan Church (UKRI STFC) Lydia Jowitt (UKRI STFC) Mark Prydderch (UKRI STFC) Matt Roberts (UKRI STFC) Matt Wilson (UKRI STFC) Matthew Hart (UKRI STFC) Matthew Veale (UKRI STFC) Paul Seller (UKRI STFC) Rhian Mair Wheater (UKRI STFC) Stephen Bell (UKRI STFC) Thomas Gardiner (UKRI STFC) Tim Nicholls (UKRI STFC)

Presentation materials