The CHORUS honeycomb tracker and its bitstream electronics

The CHORUS experiment searches for nu(mu)nu(tau) oscillation. To aid in the momentum reconstruction of charged hadrons, a honeycomb tracker was built with three orientations of six planes each. The planes are manufactured by point-welding together two precision folded conductive polycarbonate foils, forming hexagonal tubes with 30 mu m thick anode wires in the center. The honeycomb tracker in CHORUS is read out using a bitstream principle. The amplified signal of each wire is binary sampled every 5 ns and stored in a 256 bit circular buffer, implemented in dual-port memories. This technique allows a full reconstruction of a 1.28 mu s history of each wire. Eighteen cards, each handling 72 wires, are read out over a single flat cable using a card-to-card pipeline. (C) 1998 Elsevier Science B.V. All rights reserved