Nuclear Matter Expansion Parameters from the Measurement of Differential Multiplicities for Lambda Production in Central Au+Au Collisions at AGS

The double differential multiplicities and rapidity distributions for Lambda hyperon production in central Au+Au interactions at AGS in the range of rapidities from 1.7 to 3.2 and the range of transverse kinetic energies from 0.0 to 0.7 GeV are parametrized in terms of the the Blast Wave approximation. The longitudinal and transverse radial expansion parameters and the mean temperature of Lambda hyperons after the freeze-out of the nuclear matter are presented. The predictions of the RQMD model with and without mean field potentials are compared to our data. Both variants of RQMD are parameterized in terms of the Blast Wave model and the results of such parameterizations are compared to the experimental ones. It is found that inclusion of the mean field potentials in RQMD is essential to account for the strong expansion observed in the data.Comment: 20 pages, LaTeX using elsart.sty, 10 encapsulated postscript figure

MPS II drift chamber system

The MPS II detectors are narrow drift space chambers designed for high position resolution in a magnetic field and in a very high particle flux environment. Central to this implementation was the development of 3 multi-channel custom IC's and one multi-channel hybrid. The system is deadtimeless and requires no corrections on an anode-to-anode basis. Operational experience and relevance to ISABELLE detectors is discussed

High-luminosity considerations

There appears to be some controversy over how high a luminosity one can use before a variety of detector limitations impose a practical limit. Factors leading to flux limitations for a variety of detector types are discussed, and practical considerations to extending those limits are reviewed. Also, a method of reducing the effects of pileup inherent in calorimeter use at L = 10/sup 33//cm/sup 2//sec is given

Charged particle detector system for ISABELLE spectrometers

A detector system combining the good time resolution and low dead time of PWC's and the good space resolution of drift chambers is proposed for use in ISABELLE spectrometers. Central to this detector is the development of two integrated electronic circuit systems. The detectors are described with special emphasis on the electronic systems. The detector system proposed will be capable of handling particle flux rates typical of conventional PWC's yet providing a spacial resolution of 100 ..mu..m. Another advantage is that a large area detector of such performance will become technically feasible as well as economicaly viable. The detector is a conventional narrow anode spacing drift chamber with field wires. A digital delay-time encoder circuit is used for readout

MPS II: a tracking detector system for large high rate experiments

The MPS II tracking detector system, developed for a variety of low cross section experiments that are only practical in a high beam rate environment, is described. It was built as a general purpose device for use in a fixed target (AGS) situation where the beam passes through all elements of the detector. The electronics is dead-timeless so that high efficiency is achieved at event rates as high as 10/sup 6//sec/ch. This capability would allow these detectors to be used as close as 20 cm from a hadron-hadron collider at 1 Tev of luminosity up to 10/sup 33//cm/sup 2//sec. The detector is a multilayer-modular drift chamber using stereo projections to provide for 3-dimensional event reconstruction. (WHK

MPS II drift chamber system and relevance to Isabelle experiments

The MPS drift chamber structure is shown, and the design process is discussed. Specifications are given for the chambers and its electronics. (GHT

Report on application specific integrated circuits for relativistic heavy ion detectors

Detector systems for RHIC experiments are invariably going to be large and complex. Thus it behooves the planners to incorporate elements that have little need for adjustment, calibration and correction to the produced data. For example, if power, size and cost considerations permit, time can be digitized directly (i.e. with counters, shift registers, etc.) where no adjustments, calibrations or corrections are required. The circuit either works correctly or not at all. This kind of circuit behavior is extremely valuable in detectors with 10/sup 5/ or more channel elements. In analog to digital conversion applications, direct conversion (i.e. flash ADC) may be prohibitive in cost, size and power. Here major effort must be given to minimize the magnitude of offset and conversion gain variance. Where possible self correction and adjustment should be applied at the subsystem level