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.
The Time of Flight Detector at CDF
A Time-of-Flight detector (TOF) has been incorporated into the CDF-II experiment in order to provide charged kaon identification to improve neutral B meson flavor determination. With an expected time-of-flight resolution of 100 ps, the system will be able to provide 2 standard deviation separation between K± and π± for momenta p < 1.6 GeV/c, complementing the specific ionization energy loss dE/dx measured with the new drift chamber.
Anomalous Annealing Behavior of Arsenic Implanted Silicon as a Function of Dose and Energy
Anomalous annealing behavior of damage in As implanted Si has been investigated by channeling effect measurements. Room temperature As implants with doses from 1014 to 2 × 1016cm-2 at energies ranging from 50 to 250 keV into Si were annealed over the range of 600°C to 1100°C. Anneal temperatures ≥ 950°C reduce the disorder for ion doses of 0.5 to 1 × 1016 cm-2 at energies between 50 and 250 keV. Anomalously high residual disorder was found for the intermediate doses of 2 × 1014 to 2 × 10/cm2 implanted above 100 keV. For this intermediate dose, annealing of implants performed at liquid nitrogen temperatures did not show significant reduction in this damage. However implants at 200° to 300°C indicate a lower amount of damage compared to the room temperature implants.