Studies with cathode drift chambers for the GlueX experiment at Jefferson Lab

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2017-02, Vol.845 (C), p.281-284
• Main Authors: Pentchev, L., Barbosa, F., Berdnikov, V., Butler, D., Furletov, S., Robison, L., Zihlmann, B.
• Format: Article
• Language: English
• Subjects: Avalanche; Cluster counting; Drift chamber; ENGINEERING; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Tracking
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2016.04.076

A drift chamber system consisting of 24 1m-diameter chambers with both cathode and wire readout (total of 12,672 channels) is operational in Hall D at Jefferson Lab (Virginia). Two cathode strip planes and one wire plane in each chamber register the same avalanche allowing the study of avalanche development, charge induction process, and strip resolution. We demonstrate a method for reconstructing the two-dimensional distribution of the avalanche “center-of-gravity” position around the wire from an 55Fe source with resolutions down to 30μm. We estimate the azimuthal extent of the avalanche around the wire as a function of the total charge for an Ar/CO2 gas mixture. By means of cluster counting using a modified 3cm-gap chamber, we observe significant space charge effects within the same track, resulting in an extent of the avalanche along the wire. [Display omitted] •24 drift chambers with two-cathode and wire readout operational at JLab.•Precise reconstruction of the 2D position of the avalanche around the wire.•Azimuthal extent of the avalanche estimated for an Ar/CO2 gas mixture.•Space charge effects within the same track observed by means of cluster counting.