J. Kapustinsky

The L3 silicon microvertex detector

Abstract The design and construction of the silicon strip microvertex detector (SMD) of the L3 experiment at LEP are described. We present the sensors, readout electronics, data acquisition system, mechanical assembly and support, displacement monitoring systems and radiation monitoring system of the recently installed double-sided, double-layered SMD. This detector utilizes novel and sophisticated techniques for its readout.

Temperature effects on radiation damage to silicon detectors

Abstract Motivated by the large particle fluences anticipated for the SSC and LHC, we are performing a systematic study of radiation damage to silicon microstrip detectors. Here we report radiation effects on detectors cooled to 0°C (the proposed operating point for a large SSC silicon tracker) including leakage currents and change in depletion voltage. We also present results on the annealing behavior of the radiation damage. Finally, we report results of charge collection measurements of the damaged detectors made with an 241 Am α source.

A fast timing light pulser for scintillation detectors

Abstract We report on the development of a compact, inexpensive and fast light pulser system designed to set up the timing of scintillators in a medium energy physics spectrometer.

PHENIX inner detectors

Abstract The timing, location and particle multiplicity of a PHENIX collision are determined by the Beam–Beam Counters (BBC), the Multiplicity/Vertex Detector (MVD) and the Zero-Degree Calorimeters (ZDC). The BBCs provide both the time of interaction and position of a collision from the flight time of prompt particles. The MVD provides a measure of event particle multiplicity, collision vertex position and fluctuations in charged particle distributions. The ZDCs provide information on the most grazing collisions. A Normalization Trigger Counter (NTC) is used to obtain absolute cross-section measurements for p–p collisions. The BBC, MVD and NTC are described below.

Coherent eta -meson production in the reaction pi -+3He--> eta +t.

The reaction {pi}{sup {minus}}+{sup 3}He{r arrow}{eta}+{ital t} has been observed by detecting {eta}{r arrow}2{gamma} decays. The observed forward-angle cross sections vary from {similar to}100 {mu}b/sr at 680 MeV/{ital c} to {similar to}2 {mu}b/sr at 590 MeV/{ital c}. Distorted-wave impulse-approximation calculations reproduce the shape but underestimate the magnitude of the observed cross section. These cross sections are approximately 100 times larger than those for the reaction {ital p}+{ital d}{r arrow}{eta}+{sup 3}He measured at similar {eta} center-of-mass energies.

The L3 Silicon Microvertex Detector: installation and results on 1993 performance

Abstract The status of the Silicon Microvertex Detector (SMD) and its installation into the LEP-L3 experiment are presented, highlighting novel features and sophisticated techniques. Preliminary results based on 1993 data are given and compared with Monte Carlo predictions, to understand the detector performances and its tracking capabilities.

Design and performance of beam test electronics for the PHENIX Multiplicity Vertex Detector

The system architecture and test results of the custom circuits and beam test system for the Multiplicity-Vertex Detector (MVD) for the PHENIX detector collaboration at the Relativistic Heavy Ion Collider (RHIC) are presented in this paper. The final detector per-channel signal processing chain will consist of a preamplifier-gain stage, a current-mode summed multiplicity discriminator, a 64-deep analog memory (simultaneous read-write), a post-memory analog correlator, and a 10-bit 5 /spl mu/s ADC. The Heap Manager provides all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Beam test (16-cell deep memory) performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 /spl mu/ n-well CMOS process used for preamplifier fabrication.

A multiplicity-vertex detector for the PHENIX experiment at RHIC

Abstract A Multiplicity-Vertex Detector (MVD) has been designed, and is in construction for the PHENIX Experiment at the Relativistic Heavy Ion Collider (RHIC). The 35 000 channel silicon detector is a two-layer barrel comprised of 112 strip detectors, and two disk-shaped endcaps comprised of 24 wedge-shaped pad detectors. The support structure of the MVD is very low mass, only 0.4% of a radiation length in the central barrel. The detector front-end electronics are a custom CMOS chip set containing preamplifier, discriminator, analog memory unit, and analog-to-digital converter. The system has pipelined acquisition, performs in simultaneous read/write mode, and is clocked by the 10 MHz beam crossing rate at RHIC. These die, together with a pair of commercial FPGAs that are used for control logic, are packaged in a mutlichip-module (MCM). The MCM will be fabricated in the High-Density-Interconnect (HDI) process. The prototype MCM design layout is described.

A 32-channel preamplifier chip for the multiplicity vertex detector at PHENIX

The TGV32, a 32-channel preamplifier–multiplicity discriminator chip for the multiplicity vertex detector (MVD) at PHENIX, is a unique silicon preamplifier in that it provides both an analog output for storage in an analog memory and a weighted summed-current output for conversion to a channel multiplicity count. The architecture and test results of the chip are presented. Details about the design of the preamplifier, discriminator, and programmable digital–analog converters performance as well as the process variations are presented. The chip is fabricated in a 1.2 μm, n-well, complementary metal–oxide–semiconductor process.

The design and construction of a Pb/scintillator sampling calorimeter with wavelength shifter fiber optic readout

Abstract A Pb/scintillator sampling calorimeter covering the pseudorapidity interval of η = 0.83 to 4.20 has been designed and constructed for Experiment 814 of Brookhaven National Laboratory. The calorimeter uses wavelength shifting optical fibers for readout. Such fibers allow the construction of a highly granular and longitudinally compact device. A novel scheme for coupling a fiber to a scintillator plate has been designed that yields a high photoelectron response. Longitudinally, the calorimeter has a depth of four interaction lengths divided into two electromagnetic sections and two hadronic sections of 0.4, 0.4, 1.6, and 1.6 interaction lengths, respectively.