G. Bruni

A high resolution, low power time-of-flight system for the space experiment AMS

The system of plastic scintillator counters for the AMS experiment is described. The main characteristics of the detector are: (a) large sensitive area (four 1.6 m2 planes) with small dead space; (b) low-power consumption (150 W for the power and the read-out electronics of 336 PMs); (c) 120 ps time resolution. ( 1999 Elsevier Science B.V. All rights reserved.

A new gaseous detector for tracking: The blade chamber

Abstract As part of the LAA project at CERN a prototype of a streamer-chamber in which a blade, instead of a wire, is used as the amplification electrode has been built. A big advantage is that the blade can be bent to follow a curve so that a chamber can be built with cells ideally matched to the geometry of the experiment. Moreover, a blade is very rugged, it can withstand severe mechanical shocks and it is also resistant to damage by sparks. The drift time has been measured and a spatial resolution of 250 μm has been achieved. Left-right ambiguity can be solved by measuring the charge asymmetry on the walls. The coordinate along the blade is read by external pickup strips.

Limited streamer chambers for the Large Volume Detector

Abstract The tracking system of the Large Volume Detector, an underground experiment to study muons and nutrino astronomy, will use −15000 limited streamer chambers. We describe a comparison between the standard binary mixture (30% argon + 70% isobutane) and a low-hydrocarbon ternary mixture (2% argon + 10% isobutane + 88% carbon dioxide). The ternary composition results in a 400-volt-shorter single count-rate plateau, a 20% smaller primary streamer pulse-height, and a much higher streamer multiplicity. The count-rate plateaux have also been studied over a wide composition range of isobutane, argon, and carbon dioxide mixtures. We also discuss the streamer chamber quality control procedures and the results obtained from a simple of 2900 devices operated with the binary mixture.