Performance of P-type micro-strip detectors after irradiation to 7.5/spl times/10/sup 15/ p cm/sup 2

• Published in: IEEE transactions on nuclear science Vol. 52; no. 5; pp. 1903 - 1906
• Main Authors: Allport, P.P., Casse, G., Lozano, M., Sutcliffe, P., Velthuis, J.J., Vossebeld, J.
• Format: Journal Article
• Language: English
• Published: IEEE 01-10-2005
• Subjects: Collision mitigation; Conductivity; Detectors; Electronic equipment testing; elementary; Large Hadron Collider; particles; Protons; Semiconductor device noise; Semiconductor materials; Silicon; Strips
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2005.856747

Exploiting the advantages of reading out segmented silicon from the n-side, we have produced test detectors with LHC pitch but 1-cm-long strips which even after proton irradiation at the CERN PS (24 GeV protons) to 7.5/spl times/10/sup 15/ cm/sup -2/ show signal to noise greater than 8:1 using LHC speed electronics. This dose exceeds by a factor of 2 that required for a replacement of the ATLAS semiconductor tracker to cope with an upgrade of the LHC to a Super-LHC with ten times greater luminosity. These detectors were processed on p-type starting material of resistivity /spl sim/2 k/spl Omega/cm and, unlike n-in-n designs, only required single-sided processing. Such technology should therefore provide a relatively inexpensive route to replacing the central tracking at both ATLAS and CMS for Super-LHC (SLHC). The shorter strip length is required to limit the noise. Even at these extreme doses 30% of the nonirradiated signal is seen. This 7000 e/sup -/ signal (in 280-/spl mu/m-thick sensors) is very competitive with the postirradiation performance of other, more exotic detector options . The hit density expected at a SLHC would anyway require a scaling down of the sense element length (for a given pitch) to retain an occupancy of less than 1% in the layers of the central tracker. We therefore propose such a "short-strip" design as a possible low cost and easily implemented route to achieving the requirements for very high luminosity tracking at an upgraded LHC.