E. Usenko

The HARP RPC time-of-flight system

Abstract The time-of-flight system based on thin-gap glass resistive plate chambers (RPCs) for the HARP detector at CERN is described and first experience with the chamber operation and performance is reported. The system consists of 46 chambers, covers an area of 10 m 2 and has 368 readout channels. The chambers are 2 m long, 150 mm wide, and 10 mm thick and have four gas gaps of 0.3 mm each, the glass plates are 0.7 mm thick. The RPCs are operated in avalanche mode with a mixture of 90% C 2 F 4 H 2 , 5% SF 6 , and 5% C 4 H 10 .

Cross-sections of large-angle hadron production in proton–and pion–nucleus interactions V: lead nuclei and beam momenta from ±3 GeV/c to ±15 GeV/c

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% λint thick stationary lead target, of proton and pion beams with momentum from ±3 GeV/c to ±15 GeV/c. Results are given for secondary particles with production angles 20◦ < θ < 125◦. Crosssections on lead nuclei are compared with cross-sections on beryllium, copper, and tantalum nuclei.

Comments on TPC and RPC calibrations reported by the HARP collaboration

The HARP Collaboration recently published calibrations of their TPC and RPC detectors, and differential cross-sections of large-angle pion production in proton-nucleus collisions. We argue that these calibrations are biased and cross-sections based on them should not be trusted.

Time resolution of a 6-gap resistive plate chamber with strip readout

A 6-gap glass resistive plate chamber with a strip readout was tested on the beam of the U-70 accelerator at the Institute for High Energy Physics. A time resolution of ∼45 ps was attained at an efficiency of >98%. The position resolution along a strip was estimated to be ∼1 cm.

Studying the counting rate capability of a glass multigap resistive plate chamber at an increased operating temperature

It is shown that a multigap resistive plate chamber made of commercial float glass is capable of sustaining high counting rates at an increased operating temperature. Two glass chambers were investigated on the test beamline of the U-70 accelerator at the Institute for High Energy Physics. The required radiation flux density at the detector was produced by means of radioactive sources. The time resolution of 80 ps or better was attained at a rate of ∼20 kHz/cm2 and an operating temperature of 45°C.