Abstract
The Mark III is a new general purpose detector being built for SPEAR by a collaboration from Caltech, Illinois, Santa Cruz, SLAC and Washington. The configuration has been optimized for the study of exclusive final states formed by the weak decays of charmed particles or heavy leptons. Some noteworthy aspects of the detector are:(1) A track-finding trigger which finds correlations between drift chamber hits in the non-bend as well as the bending plane. Such a trigger reduces cosmic ray and beam-gas background.(2) A drift chamber cell configuration which resolves the left-right ambiguity and allows an in situ measurement of drift velocity.(3) A group of 384 wires placed close to the interaction region which permits particle separation by dE/dx on the 1/β2 portion of the energy loss curve. This technique yields 2σ π/K separation up to 700 MeV/c over 94% of 4π. Time of flight measurements permit independent separation to higher momenta over 80% of 4π.(4) The shower counters, consisting of 24 layers of 0.5 r.l. lead plates separated by drift chambers, are placed within the solenoid coil, in order that photon efficiency at low energy not be compromised.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
