Proposal for a New High Precision Particle Detector
THE precision commonly quoted when measuring the position of a charged particle track is ±0.3 mm for wire plane spark chambers1, ±0.4 mm for streamer chambers2 and ±0.7 mm for multiwire proportional chambers3,4. With the onset of the new generation of synchrotrons there is a need for detectors with better resolution. This arises from the fact that the accelerated particles will receive only small deflexions in analysing magnets. This article consists of a proposal for a detector that will provide the necessary increase in resolution.
Design and performance of wire spark chambers and magnetostrictive delay line readout system
Abstract We describe a wire spark chamber system having magnetostrictive delay line readout that was used in an experiment at the 184″ Berkeley Synchrocyclotron. The design and performance of the chambers, the electronics used to produce the direct digitization of the spark locations, and the analysis of the digital information are discussed. The spark chambers with 1 mm wire spacing had a spatial resolution of about 0.3 mm. In conjunction with an analyzing magnet forming a magnetic spectrometer, the spark chamber system achieved better than 1% momentum resolution for particles in the range of 200–320 MeV/ c . The data analysis was completed within several hours after acquisition, enabling the experimenters to take advantage of the information while the experiment was still in progress.
Spark Chamber Pulsing System
A spark chamber pulser is described in which several avalanche transistors and a step‐up transformer drive directly an air spark gap whose trigger electrode is surrounded by barium titanate dielectric. Output pulses of from 1 to 25 kV with a risetime of 1 nsec and an output impedance of less than 1 Ω can be obtained. The total delay from the 1‐V input pulse to the high voltage output pulse ranges from 17 to 65 nsec depending on the desired voltage and the mode of operation of the spark gap. Jitter times are less than 3 nsec. When Elkonite‐tipped electrodes are used, the gap life is in excess of 5 000 000 pulses. Methods are given for reducing the delay to less than 25 nsec at 20 kV and the recovery time to less than 200 μsec at 10 kV.