First-year experience with the BaBar silicon vertex tracker

Citation
C. Bozzia et al., First-year experience with the BaBar silicon vertex tracker, NUCL INST A, 473(1-2), 2001, pp. 7-16
Citations number
8
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
ISSN journal
0168-9002 → ACNP
Volume
473
Issue
1-2
Year of publication
2001
Pages
7 - 16
Database
ISI
SICI code
0168-9002(20011101)473:1-2<7:FEWTBS>2.0.ZU;2-3
Abstract
Within its first year of operation, the BaBar Silicon Vertex Tracker (SVT) has accomplished its primary design goal, measuring the z vertex coordinate with sufficient accuracy as to allow the measurement of the time-dependent CP asymmetry in the neutral B-meson system. The SVT consists of five layer s of double-sided. AC-coupled silicon-strip detectors of 300 mum thickness with a readout strip pitch of 50-210 mum and a stereo angle of 90 degrees b etween the strips on the two sides. Detector alignment and performance with respect to spatial resolution and efficiency in the reconstruction of sing le hits are discussed. In the day-to-day operation of the SVT., radiation d amage and protection issues were of primary concern. The SVT is equipped wi th a dedicated system (SVTRAD) for radiation monitoring and protection, usi ng reverse-biased photodiodes. The evolution of the SVTRAD thresholds on th e tolerated radiation level is described. Results on the first-year radiati on exposure as measured with the SVTRAD system and on the so far accumulate d damage are presented. The implications of test-irradiation results and po ssible future PEP-II luminosity upgrades on the radiation limited lifetime of the SVT are discussed. (C) 2001 Elsevier Science B.V. All rights reserve d.