Characterisation of an epitaxial GaAs/Medipix2 detector using fluorescence photons

✍ Scribed by Lukas Tlustos; M. Campbell; C. Fröjdh; Pasi Kostamo; Seppo Nenonen

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 459 KB
• Volume: 591
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2008.03.020

✦ Synopsis

A high-purity GaAs sensor of 110 mm thickness has been bump bonded to a Medipix2 readout chip. The room temperature spectroscopic response of this device to fluorescence photons in the energy range from 8 to 28 keV is presented and compared to the response of a 300 mm thick Si sensor, also bonded to a Medipix2 chip. The measured photopeak responses are used to calibrate both detectors. The depth of depletion of the GaAs sensor is estimated to be $50 mm at 140 V sensor bias voltage from measurements made using the 8 keV Ka line of a Cu target X-ray tube.