J. A. Crittenden

Construction and Operation of a Large Ring-Imaging Cerenkov Detector

We have constructed a large-aperture ring-imaging Cerenkov counter, intended to identify high momentum hadrons in a high pt experiment at Fermilab (E605). To date we have performed a preliminary analysis on a small subset of our data, taken during the initial operation of our counter (April-June 1982). We have obtained ¿/K separation with good efficiency from about 60 GeV/c to 120 GeV/c in momentum under high luminosity conditions (~5 × 109 protons/second on target). Approximately 84% of all single-track events having at least one detected photon have been unambiguously identified. Cerenkov photons were detected by a multi-step avalanche chamber via the photoionization of triethylamine (TEA) vapor, and a mean number of 2.8 photons per event was detected for the highest velocity particles. Improvements in photon reconstruction are expected, especially as we refine our tracking procedures.

A Data Acquisition System for Elementary Particle Physics

The data acquisition system experiment 605 at the Fermi National Accelerator Laboratory employs a set of data transfer protocols developed at Columbia University and implemented in the Nevis Laboratories Data Transport System. We describe the logical design of the Transport System, its physical realization, and its particular application during the Spring, 1982 data run of experiment 605. During that run it served as the interface between the data latches and a megabyte of fast memory, operating at a data transfer rate of 200 nsec/16-bit word. Up to two thousand events were read out during the one second beam spill, each event consisting of about 250 words. We include details of proposed improvements to the data acquisition system and append a brief comment of the need for inexpensive, versatile readout systems in experimental elementary particle physics.

Use of a parallel, pipelined, event processor in a massive dimuon experiment

Abstract We have constructed and operated a high-speed parallel pipelined event processor, used to trigger data acquisition in a massive muon pair experiment at Fermilab. The processor is constructed of simple, general-purpose modules designed to operate on 16-bit data words synchronously and in parallel at speeds up to 40 MHz. It uses information from hodoscopes and wire chambers to reconstruct tracks in the bend view of a magnetic spectrometer, calculating an approximation to transverse momentum (pt) for each track and mass for the most massive pair in an event. Its algorithm is designed to find tracks originating in the target and reject tracks originating in the beam dump. Under typical running conditions, the processor rejects over 80% of lower-level triggers, while maintaining efficiency near 90% for massive muon pairs produced in the target.

π/K/p identification with a large-aperture ring-imaging cherenkov counter

Abstract The operating large aperture ring-imaging Cherenkov detector from the FNAL experiment E605 is described. Cherenkov ultraviolet photons are detected with a multi-step avalanche chamber using a He/TEA gas mixture and π/K/p separation is obtained from 50 to 200 GeV/ c .

Pi / K / p Identification with a Large Aperture Ring Imaging Cherenkov Counter

Abstract The operating large aperture ring-imaging Cherenkov detector from the FNAL experiment E605 is described. Cherenkov ultraviolet photons are detected with a multi-step avalanche chamber using a He/TEA gas mixture and π/K/p separation is obtained from 50 to 200 GeV/ c .