Edge effects in a small pixel CdTe for X-ray imaging

DOI: 10.1088/1748-0221/8/10/P10018

Authors: Diana Duarte (STFC) , Steven Bell (STFC) , John Lipp (STFC) , Andreas Schneider (Rutherford Appleton Laboratory (STFC)) , Paul Seller (STFC) , Matt Veale (STFC) , Matthew Wilson (Rutherford Appleton Laboratory (STFC)) , M A Baker (University of Surrey) , Paul Sellin (University of Surrey) , Vyacheslav Kachkanov (Diamond Light Source) , Kawal Sawhney (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Instrumentation , VOL 8 , PAGES P10018 - P10018

State: Published (Approved)
Published: October 2013

Abstract: Large area detectors capable of operating with high detection efficiency at energies above 30 keV are required in many contemporary X-ray imaging applications. The properties of high Z compound semiconductors, such as CdTe, make them ideally suitable to these applications. The STFC Rutherford Appleton Laboratory has developed a small pixel CdTe detector with 80 × 80 pixels on a 250 ?m pitch. Historically, these detectors have included a 200 ?m wide guard band around the pixelated anode to reduce the effect of defects in the crystal edge. The latest version of the detector ASIC is capable of four-side butting that allows the tiling of N × N flat panel arrays. To limit the dead space between modules to the width of one pixel, edgeless detector geometries have been developed where the active volume of the detector extends to the physical edge of the crystal. The spectroscopic performance of an edgeless CdTe detector bump bonded to the HEXITEC ASIC was tested with sealed radiation sources and compared with a monochromatic X-ray micro-beam mapping measurements made at the Diamond Light Source, U.K. The average energy resolution at 59.54 keV of bulk and edge pixels was 1.23 keV and 1.58 keV, respectively. 87% of the edge pixels present fully spectroscopic performance demonstrating that edgeless CdTe detectors are a promising technology for the production of large panel radiation detectors for X-ray imaging.

Journal Keywords: Solid State Detectors; X-Ray Detectors; Anodes; Beams; Cadmium Tellurides; Cdte Semiconductor Detectors; Comparative Evaluations; Crystals; Defects; Diamonds; Energy Resolution; Geometry; Images; Kev Range; Light Sources; Monochromatic Radiation

Subject Areas: Technique Development, Physics


Instruments: