Abstract:

The design, manufacture and testing of lightweight glass-coated beryllium spherical converging mirrors for the RICH1 detector of the LHCb experiment are described. The mirrors need to be lightweight to minimize the material budget and fluorocarbon-compatible to avoid degradation in the RICH1 C4F10 gas radiator. Results of the optical measurements for small-sized prototypes and for a full-sized prototype mirror are reported. © 2006 Elsevier B.V. All rights reserved.

Abstract:

The design, manufacture and testing of lightweight Carbon Fiber Reinforced Polymer (CFRP) converging spherical mirrors for the RICH-1 Cherenkov detector of LHCb are described. The mirrors have low areal density to minimize the amount of material in the path of traversing particles and need to be fluorocarbon compatible to avoid degradation in the C4F10 radiator gas. The total area is about 2m(2) and high reflectivity (typically 90%) over the wavelength range 200-600nm is required.

Abstract:

We report on studies of 64-channel Multianode Photo-Multiplier Tubes (MaPMTs) as photo-detectors for Ring Imaging CHerenkov (RICH) counters. The newly available 8-dynode stage MaPMT was tested in particle beams at CERN. The MaPMT signals were read out directly with the Beetle1.2 chip which was designed for the LHCb environment and operates at 40 MHz. The photon yield and signal losses were determined for a cluster of 3 × 3 close-packed MaPMTs. The performance of the 8-dynode stage MaPMT was compared to that of the 12-dynode stage MaPMT which has a larger intrinsic gain. © 2006 Elsevier B.V. All rights reserved.