The PHOBOS silicon sensors

Back, B Betts, R Ganz, R Gulbrandsen, KH Holzman, B Kucewicz, W Lin, WT Mulmenstadt, J van Nieuwenhuizen, GJ Nouicer, R Pernegger, H Reuter, M Sarin, P Tsay, V Vale, CM Wadsworth, B Wuosmaa, A Wyslouch, B

B. Back et al., The PHOBOS silicon sensors, NUCL PH B-P, 78, 1999, pp. 245-251

2

INGLESE

Article

Physics

NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS

0920-5632 → ACNP

78

1999

245 - 251

ISI

0920-5632(199908)78:<245:TPSS>2.0.ZU;2-T

PHOBOS is one of the four experiments at the Relativistic Heavy Ion Collide r at Brookhaven National Laboratory. PHOBOS almost exclusively utilizes sil icon sensors to measure charged particle multiplicity distributions and to track particles in a 2-arm spectrometer. The detector consists of about 450 silicon pad sensors. Nine different pad geometries are used to match the d ifferent physics needs of the experiment. A relatively high granularity, of up to 1536 channels per sensor, is used in the spectrometer. The multiplic ity detector uses 128 and 64 channel sensors and the charge deposition per pad is measured to determine the multiplicity of single events. All sensors are of the double-metal silicon pad type with pad sizes from 1 cm(2) up to 4 cm(2). They are produced in Taiwan by the ERSO foundry under supervision of Miracle Co. and National Central University. An extensive testing proce dure makes it possible to select sensors suited for use in PHOBOS. Detector modules consisting of up to five sensors are read out with integrated chip s of either 64 or 128 channels. The testing of the sensors and the performa nce of assembled detector modules is discussed.