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Multiplicity detector using a glow-discharge memory

Description: It has been proposed to eliminate the x-y cor relation ambiguities introduced by multiple tracks in a wire chamber by using the chamber itself as a memory. Hits in the chamber itself ignite glow discharges storing the x-y location of the hits in a correlated fashion. Glow ignition may be achieved by employing a multi-step avalanche chamber above a memory gap. Correlation is maintained during readout by successively pulsing each hit wire in one coordinate and sensing transmissions through glows in the other coordinate. Prototypes constructed by the authors are discussed along with the associated high voltage and readout systems.
Date: April 1, 1981
Creator: Mulera, T.; Elola, M.; Perez-Mendez, V. & Wiedenbeck, P.
Partner: UNT Libraries Government Documents Department

Aging of Gaseous Detectors

Description: This paper makes an overview of developments in the wire chamber aging field since the wire chamber aging workshop held at the Lawrence Berkeley Laboratory, Berkeley, California on January 16--17, 1986. The author discusses new techniques to analyze the gas impurities and the wire aging products, wire nonaging'' in clean systems, wire aging in systems containing various impurities, various examples of problems which can prime'' surfaces prior to the occurrence of the aging, and some recent aging experience with the SSC micro-straw tubes.'' 35 refs., 10 figs., 2 tabs.
Date: March 1, 1990
Creator: Va'Vra, J.
Partner: UNT Libraries Government Documents Department


Description: The average polarization of the {Sigma}{sup -} produced in the reaction {pi}{sup -} + p {yields} {Sigma}{sup -} + K{sup +} has been measured between center-of-mass angles 134{sup o} and 166{sup o} for an incident {pi}{sup -} momentum of 1145 MeV/c. A polarized proton target was used, and the {Sigma}{sup -} polarization was found by measuring the difference in the production-rate of K{sup +} mesons for protons polarized along the production-plane normal and against it. Spark chambers were used to record the {pi}{sup -} and K{sup +} trajectories, and the {pi}{sup -} momentum was obtained from a magnetic spectrometer while the K{sup +} momentum was obtained from a range telescope. Each event was kinematically reconstructed in a one constraint fit to help eliminate events produced from protons bound in heavy nuclei of the target. The {Sigma}{sup -} polarization was found to be -0.36 {+-} 0.46.
Date: October 1, 1967
Creator: Weldon, D.; Steiner, H.; Shapiro, G.; Schultz, C; Johnson, C.H.; Holloway, L. et al.
Partner: UNT Libraries Government Documents Department

Track reconstruction in the NAL 30-inch bubble chamber-wide gap spark chamber hybrid system

Description: The authors describe the track reconstruction and bubble chamber/spark chamber hookup software used in the NAL hybrid spectrometer. Results for 15-200 GeV/c tracks are presented. Further details of the physical characteristics of the hybrid system and preliminary physics results are presented in accompanying papers.
Date: January 1, 1973
Partner: UNT Libraries Government Documents Department


Description: The basic theory of operation of the triggered spark gap is established, and qualitative and quantitative engineering design data are given. From the basic twoelectrode gap, a three-electrode or triggered gap model is established with its static and dynamic triggering characteristics shown. Several geometry conditions such as gap spacings trigger electrode hole sizes and insulator effects are discussed, showing their influence upon the triggering mechanism. A suggested trigger mechanism is given based on that proposed by Sletten and Lewis for the trigatron and modified to fit the present analysis. (auth)
Date: May 22, 1959
Creator: Williams, T.J.
Partner: UNT Libraries Government Documents Department

An integrating image detector for high energy neutrons

Description: We describe an integrating cathode-pad read-out wire chamber for imaging high energy neutrons. This technology allows construction of a detector with a wide dynamic range (10{sup 4}), which is gatable, easily read out, and provides millimeter scale resolution. Results from a prototype 48 x 48 pixel array are presented.
Date: September 1, 1996
Creator: Morris, C.; Armijo, V.; Atencio, L.G. & Bridge, A.
Partner: UNT Libraries Government Documents Department

Silver Spark Spectrographic Analysis of High Purity Water

Description: A spectrographic method was developed for the complete cation analysis of high-purity water by spark excitation of the evaporated sample on pairs of silver electrodes. The procedure is fast and precise, with a minimum of sample handling and adequate sensitivity for determining verv small amounts of trace impurities. (auth)
Date: July 20, 1962
Creator: Dickinson, G. W. & Wheeler, G. V.
Partner: UNT Libraries Government Documents Department

Use of a high density lead glass tubing projection chamber in positron emission tomography and in high energy physics

Description: We describe the principle of operation of a high density Projection Chamber, in which the converter/radiator and drift field shaping structures are combined in the form of high density (5 to 6 g/cmT) lead glass tubing. The main applications of this type of detector to Medical Physics (Positron Emission Tomography) and High Energy Physics (Electromagnetic Calorimetry) are discussed.
Date: October 1, 1985
Creator: Conti, M.; Guerra, A.D.; Habel, R.; Mulera, T.; Perez-Mendez, V. & Schwartz, G.
Partner: UNT Libraries Government Documents Department

Large solid angle tracking of Monte Carlo events of heavy ion collisions in TPC magnetic spectrometers

Description: The collision of 15 GeV/nucleon sulfur and carbon or oxygen ions with various fixed targets such as carbon, sulfur, and gold is to be observed in the MPS magnetic spectrometer with a time projection chamber (TPC) module. This TPC will be placed just downstream of the target and be able to track approximately 50% of all charged particles. The design and construction of the TPC is proceeding, and prototypes of the TPC readout system have been tested and production devices are to be delivered. A TPC track reconstruction program has been developed. Monte Carlo events have been generated and tracked. The track reconstruction program consists of three parts: a local pattern recognition which associates contiguous readouts on adjacent readout wires to form a single hit; a subroutine which positions the hits into slices in the vertical plane; and the track reconstruction section. (LEW)
Date: January 1, 1986
Creator: Lindenbaum, S.J.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A. et al.
Partner: UNT Libraries Government Documents Department

Performance characteristics of large aperture, ten-cell, atmospheric pressure isobutane Cherenkov counters

Description: Two large aperture, 10 cell atmospheric-pressure isobutane Cherenkov counters were designed and constructed for a SLAC streamer chamber experiment. The rejection efficiencies for a 9 GeV/c ..pi../sup -/ were measured to be 99.838 +- .006% and 99.717 +- 008% for the two counters. The design details and performance characteristics are discussed.
Date: May 24, 1980
Creator: Hylen, J.; Ma, Z.M.; Jawahery, A.; Maruyama, T.; Milburn, R. & Thornton, R.
Partner: UNT Libraries Government Documents Department

Preliminary results from studies of limited streamer tubes with external electrode readout

Description: We report initial results from a new multichannel test facility built to study the properties of chambers constructed for the Warm Iron Calorimeter of the SLD detector as they are made. The correlation between the signal on the external electrodes and the wire is observed. A systematic study of the transition between the proportional and streamer modes of operation is given as a function of argonisobutane mixture and high voltage. The pulse height spectrum is correlated with the operational plateau of the chambers and may be used to determine optimum operating points under a variety of conditions.
Date: October 1, 1987
Creator: Callegari, G.; DiCapua, E.; Piemontese, L.; Calcaterra, A.; de Sangro, R.; De Simone, P. et al.
Partner: UNT Libraries Government Documents Department

CAMAC interface for TPC data-acquisition electronics

Description: The Time Projection Chamber (TPC) is a detector used for high-energy physics research at the Stanford PEP Accelerator. TPC requires about 17,000 channels of data acquisition, which samples on command the input to each channel at a 10 MHz rate. This high data rate is made possible by means of Charge Coupled Devices (CCDs), intelligent digitizers, and a sophisticated trigger system. The TPC-CAMAC interface described here was developed to allow experiments of smaller scale than the complete TPC to use the standard data acquisition portion of the TPC electronics, namely the amplifier, CCD and digitizer bins. These three bins, when properly interconnected and controlled by the interface control bin, form a transient digitizer with a depth of 455 samples and a maximum width of 256 channels per bin set.
Date: June 1, 1983
Creator: Sidman, S.; Olson, S. & Jared, R.
Partner: UNT Libraries Government Documents Department

Charged particle tracking in high multiplicity events at RHIC

Description: It is generally accepted that the ability to track some fraction of the charged particles produced in heavy ion collisions is very desirable. At a very minimum, one must detect the occurance of multiple interactions in a single crossing. The very tight beam structure at RHIC does not favor time separation, so the location of separate vertices seems the best solution. The limits of tracking large numbers of tracks in a solid angle approaching 4..pi.. have been explored. A model detector considered is a 2.5 m radius TPC, a true 3D tracking device. In order to estimate the particle density of a function of production angle, five Hijet Au-Au central events were used to deduce the particle density distribution as a function of polar angle. An important feature of a tracking detector is the effective ''pixel'' size - the area within which two tracks cannot be resolved. In a TPC with multistep avalanche chamber readout this is approximately 3 mm x 3 mm or approx.0.1 cm/sup 2/. Using this pixel size we have calculated the radius at which the number of particles/pixel is 0.01 and 0.1. With the exception of the region very near the beam expect these distributions aren't expected to change very much with the application of a low (approx. 0.5 tesla) magnetic field. While the actual reconstruction efficiency will depend on the fine details of the apparatus and reconstruction program, the 1% fill fraction is safe for efficiencies in the 80 to 90% region. Tracking is found to be feasible at pseudorapidities up to 3.
Date: January 1, 1985
Creator: Foley, K.J. & Love, W.A.
Partner: UNT Libraries Government Documents Department

Large magnetic spectrometer group. Convenors report

Description: This working group concentrated its efforts on possible large magnetic spectrometers for studying charged particle production in high energy nucleus-nucleus collisions at RHIC. In particular, the major efforts of the group were divided into two parts: (1) one group concentrated on a detector for tracking charged particles near mid-rapidity only, while (2) the other group considered a device for tracking particles over as much of the 4..pi.. solid angle as possible. Both groups were interested in being able to detect and track as wide a range of particles (primarily hadrons) as practical, in order to isolate the possible production of a quark-gluon phase in central nucleus-nucleus collisions.
Date: January 1, 1985
Creator: Lindenbaum, S.J. & Schroeder, L.S.
Partner: UNT Libraries Government Documents Department

Triggering the LBL time projection chamber

Description: A fast digital trigger was built for the LBL Time Projection Chamber (TPC) installed in the PEP-4 detector at SLAC. The TPC is an innovative High Energy Physics detector which will provide particle identification from dE/dx information within the tracking volume. The TPC trigger uses discriminator signals from 2220 dE/dx wire channels to require a track of ionization in the TPC which originates from the colliding beam intersection region. The trigger processing is performed as the ionization drifts onto the proportional wires and is completed 17 ..mu..s after beam crossing. This report describes the basic operation of the TPC detector and its trigger; a pretrigger which uses prompt TPC information from the endcap region; and the electronic implementation. The trigger can be tested with realistic simulated patterns of ionization deposits in the TPC which are stored in local memories. Test results from electronic simulations and first results of a test with cosmic rays are shown.
Date: October 1, 1981
Creator: Ronan, M.; Millaud, J. & McGathen, T.
Partner: UNT Libraries Government Documents Department

Electromagnetic shower development and applications to sampling calorimeters

Description: The application of electromagnetic theory to particle interactions is an old subject which represented one of the early successes in the study of particle interactions and fundamental forces. The ability to describe properties of electron, positron, and photon interactions has led to applications in numerous experimental devices used in high energy experiments. The subject is now considered to be relatively mature, but applications continue to evolve as new ideas are tried and new techniques become available. This report is a review of the underlying processes, a discussion of the application to electromagnetic calorimetry, discussions of some scaling laws and approximations that serve to guide designs of experimental devices, and examples where these principles are put to work. 13 references, 10 figures, 2 tables.
Date: July 1, 1984
Creator: Prescott, C.Y.
Partner: UNT Libraries Government Documents Department