Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1824826 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2011 | 4 Pages |
Abstract
X-ray imaging based on photon counting pixel detectors has received increased interest during the past years. Attached to a semiconductor of choice, some of these devices enable to resolve the spectral components of an image. This work presents the results from measuring the energy response function of a Medipix2 MXR Hexa detector, where six individual Medipix detectors were bump bonded to a 1Â mm thick cadmium telluride sensor in order to form a 3Ã2 array of 4.2Ã2.8Â cm2 size. The average FWHM of the photo peak of an 241Am source was found to be 2.2 and 2.1Â keV for single pixels and bias voltages of 200 and 350Â V, respectively, across the whole Hexa detector. This corresponds to a relative energy resolution of less than 4%. Adding up all pixel spectra of individual chips lead to an only small deterioration of energy resolution, with line widths of 2.7 and 2.5Â keV. In general, a lower detection efficiency was observed for the lower voltage setting, along with a shift of the peak position towards lower energies.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
Thomas Koenig, Andreas Zwerger, Marcus Zuber, Patrick Schuenke, Simeon Nill, Ewald Guni, Alex Fauler, Michael Fiederle, Uwe Oelfke,