W. Selove

A high P T muon trigger processor

A high P/sub T/ muon trigger has been designed and built for application in E771, an 800 GeV experiment on beauty hadrons at Fermilab. The trigger processor uses two-dimensional pad chamber signals to identify straight line trajectories downstream of a single analyzing magnet. The trigger processor works at an interaction rate higher than 10/sup 7/ Hz with a short processing time of about 150 ns. The P/sub T/ threshold is selectable and variable from 0.6 GeV/c to more than 1 GeV/c. It takes about 6000 input signals from three to four detector planes to recognize 40000 high P/sub T/ patterns out of several million possible combinations. The background rejection in the initial test run, using only the larger y-angle region, ranged from 10 to 30.<<ETX>>

Cherenkov and Scintillation Light Measurements with Scintillating Glass, SCG1C

We have been able to observe and measure both the direct Cherenkov (C) and the Scintillation (S) light components from scintillating glass, distinctly separated in time. This has important implications for hadron calorimetry, electron/hadron separation and low energy particle identification.

Tests for a new type of calorimeter, the SPED☆

Abstract A new type of sampling calorimeter is described, in which the readout system would use large area vacuum photodiodes. Tests are reported which indicate that satisfactory signal to noise ratios can be obtained for sampling hadron calorimeters of typical size.

Scintillator-waveshifter light measurements

Abstract A series of measurements is presented on the number of photoelectrons produced and the attenuation using a series of new scintillators and waveshifter materials. Possible applications are mentioned.

A Two-Jet Calorimeter Experiment at Fermilab

A double arm calorimeter and drift chamber system has been used to study high pT jets at Fermilab in 130, 200, and 400 GeV collisions with a hydrogen target. The response of the calorimeter to jets is discussed. Data are presented on the transverse momentum of partons in the pion and proton and on the pion structure function.

A high P/sub T/ muon trigger processor

High P/sub T/ provide an important means of identifying heavy-quark events in hadroproduction experiments. A fast high P/sub T/ muon trigger processor has been designed, built, and tested for application in E771, an 800-GeV experiment on beauty hadrons at Fermilab. The trigger processor used two-dimensional pad chamber signals to identify straight-line trajectories downstream of a single analyzing magnet. High P/sub T/ muons have trajectories with relatively little deviation by the magnet. These were made to give a trigger, with a processing time of about 150 ns. >

A Modular Calorimeter System for Use in High Energy Physics

We have designed and built a modular hadron calorimeter for the study of high energy particle interactions which produce particles of high transverse momentum. The energy resolution of this system, and the triggering method for selecting the interactions of interest are described.

Signal and Noise Measurements for Muons in Scintillating Glass with Vacuum Photodiode Readout

We have been able to measure 6 photoelectrons per MeV of energy loss in scintillating glass, SCG-1, using large area vacuum photodiodes for readout with a signal to noise ratio of about 4.5.

An anti-cherenkov photomultiplier tube

Abstract We have designed a special photomultiplier tube (PMT), with very much reduced sensitivity to Cherenkov light produced in the end window. These PMTs have been produced for us by EMI, and have been used in a modular calorimeter array. The design eliminates a “hot-spot” problem which was of intolerable magnitude in our application.

Silicon microstrip electronics operating with 20 ns FWHM signals

For experiment E771 at Fermilab, semicustom integrated circuit (IC) preamplifiers and discriminators have been designed to operate at near single-bucket speed, i.e. to give signals, from a silicon microstrip detector (SMD), shaped to 15 or 20 ns FWHM. Measurements of signal size, signal-to-noise ratio (SNR), and noise rate and signal efficiency versus discriminator threshold setting were made. The test setup used an SMD plane 300- mu m thick with 50- mu m strips and the prototype ICs produced for experiment E771. Signals were produced by near-relativistic beta rays. The test setup had somewhat larger detector capacitance (C/sub d/ approximately=25 pF) than the final experiment detector will have. For tracks passing through the SMD plane nearly perpendicularly, good efficiency was found at acceptable noise rates. When the signal comes almost entirely from a single strip, the SNR is about eight to one. Under these conditions, when the discriminator threshold is set to give about 0.001 to 0.002 noise hits per strip per trigger, the latching efficiency is above 95%. For tracks at an appreciable angle from perpendicular, the deposited charge is shared between strips. For tracks with 60% of the charge or more in a single strip, the efficiency is well over 90%. >