F. Azfar

Performance of the CLEO III LiF-TEA ring imaging Cherenkov detector in a high-energy muon beam

Abstract The CLEO III Ring Imaging Cherenkov detector uses LiF radiators to generate Cherenkov photons which are then detected by proportional wire chambers using a mixture of CH 4 and TEA gases. The first two photon detector modules which were constructed, were taken to the Fermilab and tested in a beam dump that provided high-momentum muons. We report on results using both plane and “sawtooth”–shaped radiators. Specifically, we discuss the number of photoelectrons observed per ring and the angular resolution. The particle separation ability is shown to be sufficient for the physics of CLEO III.

Test beam results from the CLEO III LiF-TEA RICH

Abstract The CLEO collaboration is preparing a major upgrade of its present detector including a RICH detector for particle identification. This subdetector system follows the ‘proximity focussing’ design and uses Lithium Fluoride (LiF) crystal radiators and MWPCs filled with a CH 4 /TEA gas mixture. Part of the radiator crystals will have the new ‘sawtooth’ geometry. We have tested the first two of the 30 detector modules together with the first radiator crystals in a muon halo beam at Fermilab. For the measurement of the Cherenkov angle we obtain a single photon measurement error of 13.5xa0mrad for the conventional planar radiator. With 14 detected photons we find a resolution per track of 4.5xa0mrad. In the first measurement ever of a ‘sawtooth’ radiator we achieve a resolution of 11.8xa0mrad for single photons and 4.8xa0mrad per track for 12.3 detected photons with a reduced geometric acceptance. These results fulfill CLEO III requirements.

The ring imaging detector for CLEO III The CLEO III Ring Imaging Cherenkov detector

The CLEO detector is undergoing major improvements in conjunction with a high luminosity upgrade of the CESR e+e− collider. A novel element is a state of the art particle identification system, based on a proximity focused Ring Imaging Cherenkov detector. This detector will provide an excellent hadron identification at all the momenta relevant to the study of the decays of B mesons produced at the ϒ(4S) resonance. Some features unique to our design will be discussed together with some results achieved on individual components.

Status of construction and first tests of the CLEO III RICH

The CLEO collaboration is preparing a major upgrade of its present detector including a RICH detector for particle identification. This subdetector system follows the proximity focussing design and uses Lithium Fluoride (LiF) crystal radiators and MWPCs as photon detectors. These chambers are filled with a CH/sub 4//TEA gas mixture and have a Calcium Fluoride (CaF/sub 2/) crystal photon entrance window. Part of the radiator crystals will have the new sawtooth geometry. We have constructed two of the 30 detector modules and tested these together with the first planar and sawtooth radiator crystals in a muon halo beam at Fermilab. For the measurement of the Cherenkov angle we obtain a single photon measurement error of 13.5 mrad for the conventional planar radiator. With 14 detected photons we find a resolution per track of 4.5 mrad. In the first measurement ever of a sawtooth radiator we achieve a resolution of 11.8 mrad for single photons and 4.8 mrad per track for 12.3 detected photons with a reduced geometric acceptance. These results fulfil CLEO III requirements.