PSD10: 10th International Conference on Position Sensitive Detectors

Large area CdTe based spectroscopic X-ray imaging detector

11 Sept 2014, 09:50

20m

AP1&2 (University of Surrey)

Oral Paper Advances in Pixel Detectors and Integration Technologies Session 11: Pixel Detectors and Integration Technologies

Speaker

Paul Seller (RAL)

Description

Paul Seller[1], Lawrence L. Jones[1], Andreas Schneider[1], Matthew C. Veale[1], Matthew D. Wilson[1] , Steven Bell[2], Diana Duarte[2], Faith H. Green[2], Silvia Pani[2], Robert J. Cernik[3], Christopher K. Egan[3], Simon D.M. Jaques[3], Daniel O’Flynn[4], Robert D. Speller[4], James W. Scuffham[5], Thomas Connolley[6] [1] STFC-Rutherford Appleton Laboratory, Didcot, Oxfordshire, OX11 0QX, UK. [2] University of Surrey, Guildford, Surrey, GU2 7XH, UK. [3] School of Materials, The University of Manchester, Manchester, M13 9PL, UK. [4] Department of Medical Physics and Bioengineering, University College London, WC1E 6BT. [5] Department of Nuclear Medicine, Royal Surrey County Hospital, Guildford, GU2 7XX. [6] Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK. A 100mm x 100mm area X-ray detector has been built by tiling 25 modules of CdTe detectors. Each module consists of a 1mm thick CdTe detector bump bonded to an 80x80 pixel readout ASIC. Previous publications have demonstrated the use of similar single module or 4-module systems for applications such as X-ray diffraction or small area SPECT imaging. Tiling the 25 modules to create this larger array has created several technical challenges. In this paper we describe the latest X-ray imaging and spectroscopic performance of the modules and the design considerations and solutions for constructing the large array. Specifically we have achieved accurately aligned mechanics to minimise the dead areas when using the 3-side buttable modules. At the same time we have to remove heat from the array and allow high bandwidth data connection to the modules. The detector has a multi-level processing system which digitises 2x109 analogue signals per second. Each data value can represent the energy of the X-ray photon digitised to 12-bit accuracy. This raw data can be locally processed or stored and streamed off the detector for subsequent processing. This detector has 400 x 400 pixels with better than 2keV FWHM resolution giving it a capability for many disruptive applications.