This study examines the particle detection characteristics of a large solenoid magnet and spark chamber system by means of Monte Carlo simulation. Such a device would serve as a vertex spectrometer in a two magnet system. The nominal parameters are: a 25 kG axial field, a 2 meter diameter and a 3 meter length. The solenoid magnet can surround the target and measure the low momentum, large angle particles and a second magnet downstream, with a conventional gap and field would measure the fast secondaries. The axial field solenoid has ideal azimuthal symmetry and is well suited for rotating the transverse momentum vector of slow particles in hadron interactions. A detailed study of the acceptance, momentum resolution and pattern recognition properties of the solenoid system are presented. The overall conclusions are that it can measure most particles of 2 GeV/c or less very well, improve overall acceptances dramatically, fill in dead regions of decay distributions, make high invariant mass studies feasible (8 to 16 GeV/c beams) and present no obvious difficulty for the pattern recognition of tracks. A fast track recognition algorithm is presented and no major computing needs are anticipated for the magnetic field inside the solenoid.

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David W.G.S. Leith

Papers

Slac large wire spark chamber spectrometer.