DIRC – A particle identification system for BaBar Höcker, Andreas
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2000, Volume:
446, Issue:
1
Journal Article
Peer reviewed
Open access
The Detection of Internally Reflected Cherenkov light (DIRC) is a novel type of Cherenkov imaging device that has been developed, built and installed as part of the BaBar detector at the asymmetric ...B-factory PEP-II at SLAC. The DIRC is based on total internal reflection of Cherenkov photons produced and guided within thin, rectangular quartz bars covering the barrel region of BaBar. The photon detector is an array of photomultiplier tubes covering the photon phase space at the backward end of the bars. In its first few months of operation the DIRC performance has been found to achieve the design requirements. This note presents results from cosmic-ray data and an analysis of the first beam collision runs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The DIRC is a new type of Cherenkov imaging device that will be used for the first time in the BABAR detector at the asymmetric B-factory, PEP-II. It is based on total internal reflection and uses ...long, rectangular bars made from synthetic fused silica as Cherenkov radiator and light guide. The principles of the DIRC ring imaging Cherenkov technique are explained and results from the prototype program are presented. Its choice for the BABAR detector particle identification system is motivated, followed by a discussion of the quartz radiator properties and the detector design
The DIRC, a new type of ring-imaging Cherenkov detector that images internally reflected Cherenkov light, is being constructed as the main hadronic particle identification component of the BABAR ...detector at SLAC. The device makes use of 5 meter long fused silica (colloquially called quartz) bars, which serve both as the Cherenkov radiators and as light pipes for transmitting the light to an array of photo-multiplier tubes. This paper describes a program of research and development-aimed at determining whether bars that meet the stringent requirements of the DIRC can be obtained from commercial sources. The results of studies of bulk absorption of fused silica, surface finish, radiation damage and bulk inhomogeneities are discussed
The proposed next generation accelerator and synchrotron light facilities will require active feedback systems to control multi-bunch instabilities. These feedback systems must operate in machines ...with thousands of circulating bunches and with short (2--4 ns) interbunch intervals. The functional requirements for transferse (betatron) and longitudinal (synchrotron) feedback systems are presented. Several possible implementation options are discussed and system requirements developed. Results are presented from a digital signal processing based synchrotron oscillation damper operating at the SSRL/SLAC SPEAR storage ring.
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.
The front-end electronics and data acquisition system for the SLD barrel Cherenkov ring imaging detector (CRID) are described. The specifications for this system require a 1% charge division ...measurement on single e/sup -/ pulses from a wire chamber in the presence of much larger signals. Fast recovery from saturating pulses and noise levels below 2000 electrons root-mean-square for single electron pulses are required. Noise and system performance results are presented for the initial SLD engineering run data.< >
The front-end electronics of the Cerenkov Ring Imaging Detector (CRID) used in the Stanford Large Detector (SLD) spectrometer at the Stanford Linear Accelerator Center (SLAC) Linear Collider is ...described. The Plessey process provides a straightforward and low-cost path toward system miniaturization. System tests show good noise performance, calibration precision, system linearity, and signal shape uniformity over the full dynamic range.< >
We report on a laboratory experiment designed to assess risk preferences in a decision environment where real losses can occur. Specifically, we utilize an asset integration protocol designed to ...ensure that cash provided to treatment group participants by the experimenter is fully integrated into each individual's wealth. This cash is placed at stake in an incentivized risk‐preference elicitation task based on the well‐known Holt and Laury (2002, 2005) methodology. Our experimental design allows us to distinguish between the predictions of expected utility and prospect theory. We find that features consistent with expected utility theory, constant relative risk aversion and rank dependent expected utility functions, are insufficient to explain our experimental results. However, preference functions based on prospect theory, accounting specifically for loss aversion, capture the observed behaviour of participants in the experiment.
Résumé
Intégration d'un actif et prise de risque en laboratoire. Le présent rapport se penche sur une expérience en laboratoire conçue pour évaluer les préférences en matière de risque dans un environnement décisionnel où des pertes réelles peuvent être subies. Plus particulièrement, nous utilisons un protocole d'intégration d'actif conçu pour faire en sorte que les sommes versées aux participants du groupe de traitement par l'expérimentateur sont pleinement intégrées au patrimoine de chaque personne. Ces sommes sont pariées dans une tâche d'élicitation des préférences pour le risque avec incitations basée sur la méthodologie bien connue de Holt et Laury (2002, 2005). Notre plan expérimental nous permet de distinguer entre les prédictions de l'espérance d'utilité et la théorie des perspectives. Nous constatons que des éléments conformes à la théorie de l'espérance d'utilité, à l'aversion relative au risque constant et aux fonctions d'espérance d'utilité dépendante du rang ne suffisent pas à expliquer nos résultats expérimentaux. Toutefois, les fonctions de préférence basées sur la théorie des perspectives, plus particulièrement le fait de tenir compte de l'aversion à la perte, saisissent le comportement observé chez les participants à l'expérience.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We present an argument for changes in the franchise in which an elite split along economic interests uses the suffrage to influence implemented policies. Through the influence of these policies on ...the character of industrialization, we analyze the effects of franchise changes on economic growth. We identify in the social structure of society an explanation for the connection between enfranchisement and growth: when (1) there exists an economic conflict among the elite, (2) landed classes are not politically strong, and (3) there exists a critical mass of industrial workers, we observe both growth and democratization. The lack of conditions (1) or (2) resolves in stagnant autocracies while the absence of condition (3) drives growth-deterring democratic expansions. We provide historical support for our argument by analyzing the experience of eleven countries.
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BFBNIB, INZLJ, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK, ZRSKP
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