[en] Results are presented from a feasibility study of the use of UV Nitrogen lasers for the alignment of a large system of stacked drift chambers. They prove that a straight line calibration is possible over a distance of eight meters with deviations of less than 10 μm. The results could be reproduced by a computer simulation. 8 refs.; 8 figs

[en] A wedge type drift chamber is planned to be used as part of the inner detector of the DELPHI-experiment. The chamber features drift velocities (carefully controlled) proportional to the total drift distance to facilitate triggering. The gas choice and its consequences for calibration with and without magnetic field are discussed. Long-term stability and the effect of a magnetic field have been measured with a prototype drift chamber. Most tests reported here have been done with a laser beam with single wire accuracies below 20 micron. (orig.)

[en] The feasibility of using laser induced ionization tracks for accurate alignment calibration of large drift chamber systems was investigated. We succeeded in obtaining a reconstructed track that under certain conditions was straight to less than 10 μm over a distance of 4 m. The influence of ionization density, gas gain, type of discriminator, and optical alignment on the straightness was examined. (orig.)

[en] Since its introduction in 1989 the MicroStrip Gas Counter (MSGC), a gas avalanche detector, has been proposed for various tracking detectors in particle physics. In a test beam experiment using MSGCs with a 200 μm anode pitch, a position resolution as low as 30 μm has been achieved while a double track separation with an efficiency of 90% at 240 μm may be obtained. Also particle rates up to 100 kHz/mm² can be permitted. A gas gain of 2000 can easily be obtained, resulting in an efficiency of at least 95% for high rate applications. Finally, the long-since existing problem of ageing has been recently solved. Substrate sizes up to at least 250 cm² are possible at present; in future surfaces up to 3000 cm² are coming in sight. The substrate price has become low, no more than 2.5 SF/cm² for a series of a few tens. All these properties, together with the fine granularity (anode pitch ≥ 150 μm), the fast signal (∼50 ns) and the small radiation length fraction make the MSGC suited to fil the gap between solid state detectors and wire chambers. (orig.)

[en] A special chamber with 96 wires was used in the test beam at BNL from December 1980 to March 1981. The purpose of the measurement was to verify indeed improves with the number of track samples N = 96

[en] The article describes the operation of a detector of ionizing particles using metal strips deposited on an insulating substrate to collect and amplify the electrons liberated in the counter gas. It will be demonstrated, that minimum ionizing particles can be well detected with a good accuracy. A number for the stability of the gas gain will be deduced, the upper limit of the gain will be discussed. A circuit to avoid damages by micro-discharges will be presented. (orig.)

[en] Using a focused UV nitrogen laser beam, electrons were liberated from an argon-ethane gas mixture in a drift chamber. The drift time was measured for distances from the sense wire between 30 mm and 30 μm. From these measurements a drift velocity curve was derived for electric field strengths between 1 and 15 kV/cm. (orig.)

[en] This paper presents prototype work carried out on a microstrip gas detector of the type introduced by Oed [Nucl. Instr. and Meth. A263 (1986) 351]. We report on the response to gammas from a ⁵⁵Fe source and to a laser beam. Possible applications of this new device as a particle track detector are discussed. (orig.)

[en] A wedge-type drift chamber is planned to be used as part of the inner detector of the DELPHI experiment at the large electron-positron (LEP) collider at CERN. The chamber features drift velocities (carefully controlled) proportional to the total drift distance to facilitate triggering. The gas choice and its consequences for calibration with and without magnetic field are discussed. Long-term stability and the effect of a magnetic field have been measured with a prototype chamber. Most tests reported here have been done with a laser beam with single wire accuracies below 20 μm. The single wire accuracy for measuring minimum ionizing particles was found to be 80 μm. (orig.)

[en] Results are presented from a feasibility study of the use of UV nitrogen lasers for the alignment of a large system of stacked drift chambers. They prove that a straight line calibration is possible over a distance of 8 m with deviations of less that 10 μm. The results could be reproduced by a computer simulation. (orig.)