X-ray imaging using a hybrid photon counting GaAs pixel detector

Schwarz, C. et al. (1999) X-ray imaging using a hybrid photon counting GaAs pixel detector. In: 6th International Conference on Advanced Technology and Particle Physics, Villa Olmo, Como, Italy, 5-9 Oct 1998, pp. 491-496. (doi: 10.1016/S0920-5632(99)00592-7)

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Publisher's URL: http://dx.doi.org/10.1016/S0920-5632(99)00592-7


The performance of hybrid GaAs pixel detectors as X-ray imaging sensors were investigated at room temperature. These hybrids consist of 300 μm thick GaAs pixel detectors, flip-chip bonded to a CMOS Single Photon Counting Chip (PCC). This chip consists of a matrix of 64 × 64 identical square pixels (170 μm × 170 μm) and covers a total area of 1.2 cm2. The electronics in each cell comprises a preamplifier, a discriminator with a 3-bit threshold adjust and a 15-bit counter. The detector is realized by an array of Schottky diodes processed on semi-insulating LEC-GaAs bulk material. An IV-characteristic and a detector bias voltage scan showed that the detector can be operated with voltages around 200 V. Images of various objects were taken by using a standard X-ray tube for dental diagnostics. The signal to noise ratio (SNR) was also determined.The applications of these imaging systems range from medical applications like digital mammography or dental X-ray diagnostics to non destructive material testing (NDT). Because of the separation of detector and readout chip, different materials can be investigated and compared.

Item Type:Conference Proceedings
Glasgow Author(s) Enlighten ID:Watt, Dr John and Smith, Professor Kenway
Authors: Schwarz, C., Campbell, M., Goeppert, R., Heijne, E.H.M., Ludwig, J., Meddeler, G., Mikulec, B., Pernigotti, E., Rogalla, M., Runge, K., Söldner-Rembold, A., Smith, K., Snoeys, W., and Watt, J.
Subjects:Q Science > QC Physics
College/School:College of Science and Engineering > School of Physics and Astronomy
University Services > IT Services > E-Science
Journal Name:Nuclear Physics B - Proceedings Supplements

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