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The CMS central hadron calorimeter: Update

Description: The CMS central hadron calorimeter is a brass absorber/ scintillator sampling structure. We describe details of the mechanical and optical structure. We also discuss calibration techniques, and finally the anticipated construction schedule.
Date: June 1, 1998
Creator: Freeman, J.
Partner: UNT Libraries Government Documents Department

In situ calibration of the CMS HCAL detector

Description: One serious challenge for hadron calorimeters is setting the absolute calibration. Electromagnetic calorimeters in a magnetic spectrometer have the momentum of electrons to calibrate against. In addition, at hadron colliders, Z supplies a narrow resonance to determine calibrations. No such well-measured processes have been available in the past for hadron calorimeters. In high energy collisions, high Pt hadrons are not normally isolated, rather appearing as part of jets. Contamination of the energy scale by unmeasured neutrals or by leakage from adjacent particles is always a concern. There are low cross section processes that possess jets of well understood energy, for example a high pt Z recoiling off of a single jet. The high energy and luminosity of the LHC may supply enough of these events for quantities useful for calibration. In this paper we outline the possibility for doing in situ calibration using Z recoiling off of a jet events, and {ital t{anti t}} events. We also comment on the more conventional possibilities of using muons and energy-flow to calibrate.
Date: December 20, 1996
Creator: Freeman, J. & Wu, W.
Partner: UNT Libraries Government Documents Department

Uniformity requirements in CMS hadron calorimetry

Description: Practical considerations of calorimeter systems require a specification of the allowed manufacturing tolerances. The tightness of these requirements directly makes an impact on the assembly costs of the calorimeter. For that reason, a precise and well defined set of criteria is mandatory. In addition, the intrinsic limitations of hadron calorimetry define the level of accuracy needed in the manufacture of such devices. Therefore, considerations of the limitations on energy measurement accuracy due to Physics should define the needed level of effort to produce a uniform calorimetric device.
Date: February 1, 1996
Creator: Green, D.
Partner: UNT Libraries Government Documents Department

Charge integrator and encoder ASIC for readout of the CMS hadron calorimeter photodetectors

Description: A charge integrator and encoder ASIC is being developed at Fermilab for readout of the CMS hadron calorimeter photodetectors. The chip provides eight nonoverlapping ranges and is pipelined for deadtimeless operation. It is intended to be used with an FADC to digitize hybrid photodiode current pulses at 40 MHz. For each clock period, one range is selected depending on the signal magnitude, and the output of that range is fed to the FADC to form the mantissa. The selected range is encoded and output as a 3-bit digital exponent. Previous versions of this device have been designed for use with photomultipliers which can have high gain. Hybrid photodiodes have gains of only a few thousand so that a new version of the chip is needed which includes a current-mode preamplifier. The principle of the device is described and early results from a demonstrator project are presented.
Date: November 1, 1998
Creator: al., A. Baumbaugh et
Partner: UNT Libraries Government Documents Department

Design, performance, and upgrade of the D0 calorimeter

Description: The D0 detector, located at the Fermi National Accelerator Laboratory in Batavia, Illinois, USA, is a large hermetic detector designed for the study of proton-antiproton collisions at a center-of-mass energy of 2 TeV. The calorimeter is a sampling device that employs uranium absorber and liquid argon as the active material. It has been designed for the high-precision energy measurement of electrons and jets over the full solid angle, and excellent missing transverse energy resolution for enhanced neutrino {open_quotes}detection{close_quotes}. The authors report on some fundamental aspects of the D0 calorimeter`s design and performance (the latter having been measured in both test beams and during recent data taking at the Fermilab collider), and their plan for the upgrade, which has been designed to accomodate the higher luminosities anticipated after completion of the Fermilab Main Injector.
Date: January 1, 1995
Creator: Kotcher, J.
Partner: UNT Libraries Government Documents Department

Test of the DEP hybrid photodiode in 5 Tesla Magnet

Description: The CMS detector is designed so that the tile/fiber hadronic calorimeter (HCAL) is immersed in a 4 Tesla magnetic field. The Hybrid Photodiode (HPD) will be used as the photodetector. Below we present the experiment data which we obtained on the HPD behavior in a magnetic field.
Date: October 1, 1997
Creator: Green, D; Freeman, J.; Ronzhin, A.; Cushman, R. & Heering, A.
Partner: UNT Libraries Government Documents Department

Test of DEP hybrid photodiodes

Description: The goal of the measurement was to study some parameters of DEP HYBRID PHOTODIODES (HPD), and the check its performance for CMS calorimetry at LHC. The principal of the HPD operation is described. The schematic view of the HPD. The HPD is vacuum photo device composed of photocathode (PC) and a silicon PIN diode (Si) as multiplication system in a very close proximity geometry. The distance between PC and Si is of the order of several mm and has an electric field < 10 kV. The photoelectron emited by the photocathode multiply by a factor of several thousand in the silicon and the charge is collected on the HPD`s anode. Several types of HPD`s were tested. There was a single channel HPD, called {open_quotes}E-type{close_quotes} with p-side of the silicon facing the HPD`s photocathode and two multipixel HPD (DEP) namely a 25 pixel HPD and a 7 pixel HPD. Both were of {open_quotes}T-type{close_quotes} structure with n-side of silicon facing the photocathode.
Date: August 1, 1997
Creator: Baumbaugh, A.; Binkley, M. & Elias, J.
Partner: UNT Libraries Government Documents Department

Measurement of gas bremsstrahlung from the insertion device beamlines of the advanced photon source

Description: High energy electron storage rings generate energetic bremsstrahlung photons through radiative interaction of the electrons (or positrons) with the residual gas molecules inside the storage ring. The resulting radiation exits at an average emittance angle of (m{sub 0}c{sub 2}/E) radian with respect to the electron beam path, where m{sub 0}c{sup 2} is the rest mass of E the electron and E its kinetic energy. Thus, at straight sections of the storage rings, moving electrons will produce a narrow and intense monodirectional photon beam. At synchrotron radiation facilities, where beamlines are channeled out of the storage ring, a continuous gas bremsstrahlung spectrum, with a maximum energy of the electron beam, will be present. There are a number of compelling reasons that a measurement of the bremsstrahlung characteristics be conducted at the Advanced Photon Source (APS) storage ring. Although the number of residual gas molecules present in the storage ring at typical nTorr vacuum is low, because of the long straight paths of the electrons in the storage ring at APS, significant production of bremsstrahlung will be produced. This may pose a radiation hazard. It is then imperative that personnel be shielded from dose rates due to this radiation. There are not many measurements available for gas bremsstrahlung, especially for higher electron beam energies. The quantitative estimates of gas bremsstrahlung from storage rings as evaluated by Monte Carlo codes also have several uncertainties. They are in general calculated for air at atmospheric pressure, the results of which are then extrapolated to typical storage ring vacuum values (of the order of 10{sup -9} Torr). Realistically, the actual pressure profile can vary inside the narrow vacuum chamber. Also, the actual chemical composition of the residual gas inside the storage ring is generally different from that of air.
Date: March 1, 1997
Creator: Pisharody, M.; Job, P.K. & Magill, S.
Partner: UNT Libraries Government Documents Department

[SSC subsystem proposal for pre-shower and Shower Maximum Detectors]. Final report

Description: The basic purpose of this project was to devise low-cost photodetectors and arrays with large dynamic range capable of high-rate, radiation-resistant operation in multi-TeV hadron colliders. This project`s particular application was changed from the Superconducting Super Collider`s SDC detector to the Large Hadron Collider`s CMS after the Superconducting Super Collider project was cancelled. This report describes development and testing of photodetectors, and contains both a table summarizing the properties of different photodetectors and a paper on the performance of an avalanche photodiode photomultiplier tube tested at the CERN PS.
Date: December 31, 1994
Partner: UNT Libraries Government Documents Department

The D0 detector at Fermilab: Recent results and future plans

Description: The D0 Collaboration at Fermilab consists of about 400 physicists from institutions in 8 countries. The detector built by this collaboration has three main parts, a Central Detector, a liquid Argon - Uranium calorimeter and an outer muon detector. A very successful run was completed in May of 1993; analyses of this data are nearing completion and several physics results have already been presented. Another run started in January of 1994 and is still continuing. Some of the results from the first run, prospects for forthcoming physics results and plans for detector upgrades will be presented in this paper.
Date: January 1, 1995
Creator: Hoftun, J.S.
Partner: UNT Libraries Government Documents Department

The D-Zero Detector upgrade and jet energy scale

Description: A major detector upgrade project is presently underway for the D0 experiment in preparation for Run 2 of the Fermilab Tevatron collider scheduled to begin in the year 2000. The upgrade is driven by the D0 Run 2 physics goals and by the higher event rates and backgrounds expected in the new high luminosity environment. A general overview of the D0 upgrade is given in the first part of this report. The second part describes the calibration of jets observed with the D0 detector at the transverse energy and pseudorapidity range E{sub T} > 8 GeV and {vert_bar}{eta}{vert_bar} < 3.
Date: September 1, 1998
Partner: UNT Libraries Government Documents Department

Testbeam results for the CDF end plug hadron calorimeter

Description: Preliminary testbeam results for the CDF Tile-Fiber End Plug Upgrade Hadron Calorimeter (Hcal) are presented. Data were taken at incident momentum range of 5 to 230 GeV/c during 1996-7. The discussion of the {pi}-p energy response difference is motivated by the proton contamination in the hadron beam. Three effects which result in the {pi}-p response difference are studied. Measurements of the {pi}-p energy response were done at 5.4 and 13.3 GeV/c. The data agree with a calculation based on the three effects. The calculated proton contamination correction is applied to all the hadron data. The linearity and resolution of Hcal to pions are presented. The e/h parameter is extracted from the measurements of the response of Hcal to pions and positrons.
Date: December 1, 1997
Creator: Liu, J.
Partner: UNT Libraries Government Documents Department

Trigger circuits for the PHENIX electromagnetic calorimeter

Description: Monolithic and discrete circuits have been developed to provide trigger signals for the PHENIX electromagnetic calorimeter detector. These trigger circuits are deadtimeless and create overlapping 4 by 4 energy sums, a cosmic muon trigger, and a 144 channel energy sum. The front end electronics of the PHENIX system sample the energy and timing channels at each bunch crossing (BC) but it is not known immediately if this data is of interest. The information from the trigger circuits is used to determine if the data collected is of interest and should be digitized and stored or discarded. This paper presents details of the design, issues affecting circuit performance, characterization of prototypes fabricated in 1.2 {micro}m Orbit CMOS, and integration of the circuits into the EMCal electronics system.
Date: November 1, 1997
Creator: Frank, S.S.; Britton, C.L. Jr.; Winterberg, A.L. & Young, G.R.
Partner: UNT Libraries Government Documents Department

Test beam performance of the CDF plug upgrade hadron calorimeter

Description: We report on the performance of the CDF End Plug Hadron Calorimeter in a test beam. The sampling calorimeter is constructed using 2 inch iron absorber plates and scintillator planes with wavelength shifting fibers for readout. The linearity and energy resolution of the calorimeter response to pions, and the transverse uniformity of the response to muons and pions are presented. The parameter e/h, representing the ratio of the electromagnetic to hadronic response, is extracted from the data.
Date: January 13, 1998
Creator: de Barbaro, P. & Group, CDF Plug Upgrade
Partner: UNT Libraries Government Documents Department

Test beam performance of CDF plug upgrade EM calorimeter

Description: CDF Plug Upgrade(tile-fiber) EM Calorimeter performed resolution of 15%/{radical}E{circle_plus}0.7% with non-linearity less than 1% in a energy range of 5-180 GeV at Fermilab Test Beam. Transverse uniformity of inside-tower-response of the EM Calorimeter was 2.2% with 56 GeV positron, which was reduced to 1.0% with response map correction. We observed 300 photo electron/GeV in the EM Calorimeter. Ratios of EM Calorimeter response to positron beam to that to {sup 137}Cs Source was stable within 1% in the period of 8 months.
Date: January 1, 1998
Creator: Fukui, Y. & Group, CDF Upgrade
Partner: UNT Libraries Government Documents Department

Reduction of the calorimeter data with {sup 208}Pb projectiles at 158 GeV/Nucleon in the CERN experiment NA49

Description: The first heavy ion run involving a {sup 208}Pb beam at E{sub LAB} = 158 GeV/Nucleon was performed at the CERN Super Proton Synchrotron (SPS) in November-December 1994. The calibration procedures and the analysis of the calorimeter data are present.
Date: December 1, 1995
Creator: Huang, I.; Margetis, S.; Seyboth, P. & Vranic, D.
Partner: UNT Libraries Government Documents Department

Report of the Task Force on Collision Hall Limitations

Description: The Task Force on Collision Hall Limitations met March 23--26, 1987, to obtain a greater understanding of the civil construction requirements for a large scale model SSC detector and to identify limitations, if any, on overall detector scale and individual detector components that may result from civil construction limitations. To this purpose the Task Force studied civil construction techniques and limitations for both deep sites and surface or near surface sites, developed limits and criteria for model detector assembly and servicing, developed a model detector assembly scenario, and estimated an overall schedule from initiation of the design of the experimental hall complex to the completion of the assembly of the model detector. Our conclusions apply only to facilities required to house experiments of the scale of the model detector studied. From our studies it is apparent that the experimental hall complex required for SSC-scale detectors can be constructed under a variety of assumptions regarding the eventual SSC site. There may be significant differences in the schedule and the cost of the experimental hall complex between surface and deep underground locations, with the deep underground, in general, being more expensive and requiring a longer time for construction. The difference in cost and schedule for the experimental facilities for housing the model detector between a surface site and a deep underground site may amount to $25M and two years.
Date: April 1, 1987
Partner: UNT Libraries Government Documents Department

Pressurized drift tubes scintillating fiber hadron calorimetry. Final report

Description: Under this contract members of the MSU high energy physics group constructed a full-scale Pressurized Drift Tube Chamber intended for the GEM muon system at the SSC. They achieved a position resolution of <90 {mu} over the full 5 m{sup 2} area of the detector. This resolution satisfied the GEM resolution requirements of <100 {mu} by a comfortable margin. Based on their SSC work they developed a new technique for creating wire supports in drift tubes with an overall placement accuracy of <20 {mu}. This technique requires only simple jigging and can be duplicated and operated at low cost. Also, they participated in the design and testing of a hadron calorimeter prototype for GEM. This work lead the authors to develop a semi-automatic welding machine to fuse together two plastic optical fibers. Copies of this machine are currently in use in the CDF endplug upgrade at Fermilab and additional copies are used widely in calorimeter and fiber-tracker construction.
Date: March 22, 1995
Creator: Bromberg, C.; Huston, J. & Miller, R.
Partner: UNT Libraries Government Documents Department

A possible level 0 trigger scheme for the STAR EMC

Description: We propose a level 0 trigger for the STAR Electromagnetic Calorimeter, EMC, which provides a global energy sum and sums over cells appropriate for triggering on direct gammas and jets. It is implemented in analog at low level and digitally with FPGA`s at higher level. It will provide trigger information in less than 800 nanoseconds.
Date: May 1, 1994
Creator: Underwood, D.
Partner: UNT Libraries Government Documents Department

Photon physics with PHENIX

Description: In this Paper the author discusses briefly the physics motivation for extending measurements of particle production with high granularity and particle id capabilities to neutrals in PHENIX. He then discusses the technique of direct photon measurement in the presence of copious background photons from {pi}{sup o} decays. Relatively low p{sub t} photons will be measured near y=O in the lab frame. This new experimental environment of high multiplicity and low {gamma} momenta will affect both the techniques used and the type of analysis which can be performed. The Phenix Electromagnetic calorimeter is described and its capabilities illustrated with results from simulation and beam tests of the first production array.
Date: July 1, 1995
Creator: White, S.
Partner: UNT Libraries Government Documents Department

Realization of large systems. Summary talk

Description: We are facing the challenge of building four new detectors for the LHC/SSC of unprecedented size, cost and complexity. What can we learn from the experience of building the recently completed detectors that is relevant to this new challenge? To this end, a session was organized in which talks were given on the calorimeters of the four LEP detectors and on SLD, and on the three recently completed detectors that are not yet operating D0, H1, and ZEUS. In addition, presentations were made about a system study for a liquid argon calorimeter for LHC and on the calorimeter readout system for ZEUS.
Date: December 31, 1991
Creator: Derrick, M.
Partner: UNT Libraries Government Documents Department

Upgrade plans for the D0 calorimeter

Description: The D{null} detector, a large collider detector located at the Fermi National Accelerator Laboratory, has begun implementing a major detector upgrade in anticipation of the completion of the Main Injector project at the Fermilab Tevatron. The calorimeter readout has been redesigned in order to accommodate the factor of {approx} 10 increase in instantaneous luminosity and the decrease in the inter- bunch separation. Our means of dealing with the increased event rate, along with our plan for controlling overall noise levels in the calorimeter, are discussed. We also present a brief overview of the design for the detector upgrade, including a discussion of some on the more cogent physics topics that will be accessible with the factor of {approx} 20 increase over the present data sample.
Date: August 1, 1996
Creator: Kotcher, J.
Partner: UNT Libraries Government Documents Department

Rapidity gaps between jets at D{O}

Description: We present studies of jet production via color-singlet events with low particle multiplicity between the jets. A preliminary study of the multiplicity in other regions of the color singlet events and the dependence of color-singlet exchange on jet transverse energy is also presented.
Date: July 1, 1996
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department