Dj. Mercer et al., A LARGE SOLID-ANGLE ARRAY FOR HEAVY-IONS FROM APEX, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 350(3), 1994, pp. 491-502
A large solid-angle array of Low Pressure Multi-Wire Proportional Coun
ters (LPMWPCs) has been constructed as part of the ATLAS Positron Expe
riment (APEX). Eight three-element trapezoidal counters span 360-degre
es in phi and 20-68-degrees in laboratory theta. Angle sensitivity in
theta is provided by a transmission-line delay cathode, while the 24-f
old segmentation provides angle sensitivity in phi. Details are given
on the design of the counters and associated hardware. Performance of
the counters is described, based on tests with scattered heavy ions ra
nging from Ni-58 to U-238.