I. Adam

Operational experience with the DIRC detector

The DIRC, a novel type of Cherenkov ring imaging device, is the primary hadronic particle identification system for the BABAR detector at the asymmetric B-factory, PEP-II at the Stanford Linear Accelerator Center. It is based on total internal reflection and uses long, rectangular bars made from synthetic fused silica as Cherenkov radiators and light guides. BABAR began taking data with colliding beams in late spring 1999. This paper describes the performance of the DIRC during the first 2.5 years of operation.

Operation of the Cherenkov detector DIRC of BABAR at high luminosity

The DIRC (acronym for Detection of Internally Reflected Cherenkov (light)) is the ring imaging Cherenkov detector of the BABAR detector at the PEP-II ring of SLAC. It provides the identification of pions, kaons and protons for momenta up to 4 GeV/c with high efficiency. This is needed to reconstruct CP-violating B-decay final states and to provide B-meson flavour tagging for time dependent asymmetry measurements. The DIRC radiators consists of long rectangular bars made of synthetic fused silica and the photon detector is a water tank equipped with an array of 10.752 conventional photomultipliers. At the end of the year 2000 BABAR has recorded about 22 million B~B pairs reaching the design luminosity of L=3/spl middot/10/sup 33//cm/sup 2/s. The ability to keep the beam background level low at highest collision rates and the long term reliability of the DIRC components during continuous data taking are requirements of BABAR to accomplish its physics program.

First year operational experience with the Cherenkov detector (DIRC) of BaBar

The DIRC (acronym for Detection of Internally Reflected Cherenkov (light)) is a new type of Cherenkov ring imaging detector based on total internal reflection that is used for the first time in the BaBar detector at the PEP-II ring of SLAC. The Cherenkov radiators are long rectangular bars made of synthetic fused silica, the photon detector is a water tank equipped with an array of 10,752 conventional photomultipliers. The first year operational experience in the BaBar detector is presented using cosmic data and collision data in the energy region of the /spl Upsi/(4S) resonance.

Particle identification using the DIRC in BaBar

Abstract The Ba B ar DIRC runs extremely well at design luminosities, providing excellent PID in both ring and veto modes. Machine backgrounds expected as PEP-II goes to much higher luminosities (10 34 cm 2 ·s −1 or more) in the next 5 years will require faster data acquisition electronics and further shielding of the SOB from low energy machine produced gamma rays.

Status of the DIRC Detector at Babar: Early Operational Experience

A novel type of Cherenkov ring imaging particle identification system (DIRC) based on the detection of ring images produced in long, fused silica radiator bars is being used to provide hadronic particle identification in the BABAR detector at PEP-II. The DIRC concept, design, fabrication, and initial performance will be briefly described. The DIRC is now fully commissioned, and has been operating in the BABAR detector on beam line at the PEP-II B Factory since late Spring 1999.