Precision scans of the pixel cell response of double sided 3D pixel detectors to pion and x-ray beams

MacRaighne, A. et al. (2011) Precision scans of the pixel cell response of double sided 3D pixel detectors to pion and x-ray beams. Journal of Instrumentation, 6(5), P05002. (doi: 10.1088/1748-0221/6/05/P05002)

Abstract

hree-dimensional (3D) silicon sensors offer potential advantages over standard planar sensors for radiation hardness in future high energy physics experiments and reduced charge-sharing for X-ray applications, but may introduce inefficiencies due to the columnar electrodes. These inefficiencies are probed by studying variations in response across a unit pixel cell in a 55μm pitch double-sided 3D pixel sensor bump bonded to TimePix and Medipix2 readout ASICs. Two complementary characterisation techniques are discussed: the first uses a custom built telescope and a 120GeV pion beam from the Super Proton Synchrotron (SPS) at CERN; the second employs a novel technique to illuminate the sensor with a micro-focused synchrotron X-ray beam at the Diamond Light Source, UK. For a pion beam incident perpendicular to the sensor plane an overall pixel efficiency of 93.0±0.5% is measured. After a 10o rotation of the device the effect of the columnar region becomes negligible and the overall efficiency rises to 99.8±0.5%. The double-sided 3D sensor shows significantly reduced charge sharing to neighbouring pixels compared to the planar device. The charge sharing results obtained from the X-ray beam study of the 3D sensor are shown to agree with a simple simulation in which charge diffusion is neglected. The devices tested are found to be compatible with having a region in which no charge is collected centred on the electrode columns and of radius 7.6±0.6μm. Charge collection above and below the columnar electrodes in the double-sided 3D sensor is observed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stewart, Dr Graeme and Pennicard, Mr David and Maneuski, Dr Dima and MacRaighne, Dr Aaron and Bates, Dr Richard and Gligorov, Dr Vladmir and Rodrigues, Dr Eduardo and Eklund, Prof Lars and Parkes, Dr Christopher
• Authors: MacRaighne, A., Akiba, K., Alianelli, L., Bates, R., van Beuzekom, M., Buytaert, J., Campbell, M., Collins, P., Crossley, M., Dumps, R., Eklund, L., Fleta, C., Gallas, A., Gersabeck, M., Gimenez, E.N., Gligorov, V.V., John, M., Llopart, X., Lozano, M., Maneuski, D., Marchal, J., Nicol, M., Plackett, R., Parkes, C., Pellegrini, G., Pennicard, D., Rodrigues, E., Stewart, G., Sawhney, K.J.S., Tartoni, N., and Tlustos, L.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of Instrumentation
• Publisher: Institute of Physics Publishing Ltd.
• ISSN: 1748-0221
• Copyright Holders: Copyright © 2011 IOP Publishing Ltd and SISSA
• First Published: First published in Journal of Instrumentation 6(5):P05002
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher