A very light proportional chamber constructed with aluminized mylar tubes for drift time and charge division readouts

A proportional chamber made with aluminized mylar drift tubes is described. The design is optimized for lightness and good performance in drift time and charge division on resistive sense wires. The design makes it possible to minimize the effect of failures, since a broken wire does not prevent the rest of the chamber from operation, and allows a very low weight. The use of resistive wire, not common to other detectors of this kind, makes it possible to measure the longitudinal coordinate by comparing the charges collected at the two anode ends. The design of the chamber is described, its readout characteristics are examined, and preliminary results are reported.<<ETX>>