THE CHORUS HONEYCOMB TRACKER AND ITS BITSTREAM ELECTRONICS

The CHORUS experiment searches for nu(mu)<->nu(tau) oscillation. To ai d in the momentum reconstruction of charged hadrons, a honeycomb track er was built with three orientations of six planes each. The planes ar e manufactured by point-welding together two precision folded conducti ve polycarbonate foils, forming hexagonal tubes with 30 mu m thick ano de wires in the center. The honeycomb tracker in CHORUS is read out us ing a bitstream principle. The amplified signal of each wire is binary sampled every 5 ns and stored in a 256 bit circular buffer, implement ed 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 pipe line. (C) 1998 Elsevier Science B.V. All rights reserved.