2,211 research outputs found
Quartz Cherenkov Counters for Fast Timing: QUARTIC
We have developed particle detectors based on fused silica (quartz) Cherenkov
radiators read out with micro-channel plate photomultipliers (MCP-PMTs) or
silicon photomultipliers (SiPMs) for high precision timing (Sigma(t) about
10-15 ps). One application is to measure the times of small angle protons from
exclusive reactions, e.g. p + p - p + H + p, at the Large Hadron Collider, LHC.
They may also be used to measure directional particle fluxes close to external
or stored beams. The detectors have small areas (square cm), but need to be
active very close (a few mm) to the intense LHC beam, and so must be radiation
hard and nearly edgeless. We present results of tests of detectors with quartz
bars inclined at the Cherenkov angle, and with bars in the form of an "L" (with
a 90 degree corner). We also describe a possible design for a fast timing
hodoscope with elements of a few square mm.Comment: 24 pages, 14 figure
Cherenkov Light Imaging - Fundamentals and recent Developments
We review in a historical way the fundamentals of Cherenkov light imaging
applied to Ring Imaging Cherenkov Counters. We also point out some of the newer
developments in this very active field.Comment: Submitted to special edition of NIMA, Proceedings of RICH201
The BTeV RICH Front End Electronics
We report on the design and testing of novel mixed analog and digital front
end ASICs custom made for the single photon detectors considered for the BTeV
RICH system. The key features are reviewed, as well as results achieved using
electronics bench tests and beam studies.Comment: 7 pages, 4 figures, talk given at the 5th International Workshop on
Ring Imaging Cherenkov Counters (RICH2004
DIRAC Experiment at CERN: Lifetime Measurement of Pionium
The DIRAC experiment, a magnetic double arm spectrometer, aims to measure the
atom lifetime with 10% precision, using the high intensity 24
GeV/c proton beam of the CERN Proton Synchrotron. Since the value of this
lifetime of order ~s is dictated by strong interaction at low energy,
a precise measurement of this quantity enables to study characteristic pion
parameters in detail and to submit predictions of QCD to a severe check.Comment: 5 pages, 2 figures (eps and ps), conference, use dubna98.st
Tests of a proximity focusing RICH with aerogel as radiator
Using aerogel as radiator and multianode PMTs for photon detection, a
proximity focusing Cherenkov ring imaging detector has been constructed and
tested in the KEK 2 beam. The aim is to experimentally study the basic
parameters such as resolution of the single photon Cherenkov angle and number
of detected photons per ring. The resolution obtained is well approximated by
estimates of contributions from pixel size and emission point uncertainty. The
number of detected photons per Cherenkov ring is in good agreement with
estimates based on aerogel and detector characteristics. The values obtained
turn out to be rather low, mainly due to Rayleigh scattering and to the
relatively large dead space between the photocathodes. A light collection
system or a higher fraction of the photomultiplier active area, together with
better quality aerogels are expected to improve the situation. The reduction of
Cherenkov yield, for charged particle impact in the vicinity of the aerogel
tile side wall, has also been measured.Comment: 4 pages, 8 figure
DIRC DREAMS REDUX: RESEARCH DIRECTIONS FOR THE NEXT GENERATION OF INTERNALLY REFLECTED IMAGING COUNTERS *
Some general conceptual design features of total internally reflecting, imaging Cherenkov counters (DIRCs) are described. Limits of the DIRC approach to particle identification and a few features of alternative DIRC designs are briefly explored
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