3D silicon pixel detectors for the ATLAS Forward Physics experiment
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-03-20 |
| Journal | Journal of Instrumentation |
| Authors | J. Lange, E. Cavallaro, S. Grinstein, I. Lopez Paz, J. Lange |
| Institutions | Institute for High Energy Physics, InstituciĆ³ Catalana de Recerca i Estudis AvanƧats |
| Citations | 18 |
Abstract
Section titled āAbstractāThe ATLAS Forward Physics (AFP) project plans to install 3D silicon pixel\ndetectors about 210 m away from the interaction point and very close to the\nbeamline (2-3 mm). This implies the need of slim edges of about 100-200 $\mu$m\nwidth for the sensor side facing the beam to minimise the dead area. Another\nchallenge is an expected non-uniform irradiation of the pixel sensors. It is\nstudied if these requirements can be met using slightly-modified FE-I4 3D pixel\nsensors from the ATLAS Insertable B-Layer production. AFP-compatible slim edges\nare obtained with a simple diamond-saw cut. Electrical characterisations and\nbeam tests are carried out and no detrimental impact on the leakage current and\nhit efficiency is observed. For devices without a 3D guard ring a remaining\ninsensitive edge of less than 15 $\mu$m width is found. Moreover, 3D detectors\nare non-uniformly irradiated up to fluences of several 10$^{15}$\nn$_{eq}$/cm$^2$ with either a focussed 23 GeV proton beam or a 23 MeV proton\nbeam through holes in Al masks. The efficiency in the irradiated region is\nfound to be similar to the one in the non-irradiated region and exceeds 97% in\ncase of favourable chip-parameter settings. Only in a narrow transition area at\nthe edge of the hole in the Al mask, a significantly lower efficiency is seen.\nA follow-up study of this effect using arrays of small pad diodes for\nposition-resolved dosimetry via the leakage current is carried out.\n