S. Bernreuther et al., DESIGN AND PERFORMANCE OF THE LARGE HERMES DRIFT CHAMBERS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 367(1-3), 1995, pp. 96-99
Big planar drift chambers built for the downstream tracking system of
the HERMES spectrometer are described. Using the fast non-flammable ga
s mixture Ar/CO2/CF4 (90/5/5) average spatial resolutions of about 180
mu m per plane at efficiencies above 96% have been obtained from test
run data analysis.