A novel technique for the production of large area Z-coordinate readout planes for the BABAR muon system

Abstract

The B A B AR detector, at the Stanford Linear Accelerator Center is a general-purpose detector for the study of e + e - interactions at the ϒ ( 4 S ) resonance. B A B AR's muon-detection system consists of two parts: a hexagonal barrel region and two planar endcap regions each containing 18 layers of iron ( ∼ 3.6 λ ) , with resistive plate chambers within the inter-iron gaps. These chambers have suffered deterioration in performance over the past few years and are being replaced by limited streamer tube chambers in the barrel. Each layer of the system consists of a set of up to 10 streamer tube modules oriented parallel to the beamline providing the azimuthal coordinate ( Φ ) and a single “ Z-plane” with strips oriented perpendicular the streamer tubes providing the coordinate ( Z ) along the beamline. The large area Z-planes (up to 12 m 2 ) are 1 mm thick and contain 96 strips that detect the induced charge from avalanches on the streamer tube wires. This paper reports on the novel construction technique of the Z-planes.