The CDFII Time-Of-Flight Detector and Impact on Beauty Flavor Tagging
The new CDFII detector incorporates a Time-of-Flight detector (TOF), em-ploying plastic scintillator bars and ﬁne-mesh photomultipliers. Since August 2001 the TOF system has been fully instrumented and integrated into the CDFII data acquisition system. With a design goal of 100 ps resolution the TOF system will pro-vide at least two standard deviations separation between K ± and π ± for momenta p < 1 . 6 GeV/c , complementing low momentum particle identiﬁcation by means of the speciﬁc ionization energy loss measured in the drift chamber. We describe the design of the TOF detector and discuss the current status of its calibration and initial performances. Finally we review the expected impact of the TOF detector in the ﬂavor tagging of neutral B S meson.
Design and performance tests of the CDF time-of-flight system
Abstract The CDF II detector contains a time-of-flight detector consisting of 216 scintillator bars of 279 cm length and 4×4 cm2 cross-section located at a radius of 138 cm from the beam axis. The bars are installed on the inner surface of the CDF solenoid, which produces an axial field of 1.4 T. Nineteen-stage fine-mesh photomultiplier tubes are attached at both ends of the scintillator bars. Photostatistics limit the time-of-flight resolution, which is expected to be 100 ps. The primary physics motivation is K± identification for improved neutral B meson flavor determination.
Results from a 20 scintillator bar time-of-flight test system located inside the 1.4 T CDF solenoid
Abstract This paper reports on a test time-of-flight (TOF) system that operated in the Collider Detector at Fermilab (CDF) during p p Tevatron collider operation at s =1.8 TeV in the fall 1995 running period. The TOF system consisted of 20 130×4×4 cm 3 long Bicron BC408 scintillator bars, with each end of the bars fitted with a small compound parabolic concentrator and a 16-stage R5946 Hamamatsu fine-mesh photomultiplier. The electronics chain consisted of a custom designed preamplifier, constant fraction discriminator, and commercial TDC and ADC FASTBUS modules read out with the CDF data acquisition system. The counters were installed between the Central Tracking Chamber and the 1.4 T superconducting solenoid at a mean radius of 140 cm. We report a procedure for calculating the t0 time from all tracks in an event, the timing resolution, and the particle identification performance of this system.