DRIFT MULTIWIRE PROPORTIONAL COUNTER FOR COSMIC SOFT-X-RAY IMAGING

Multiwire proportional counters with 1 µm polypropylene windows, of dimensions 75 mm × 75 mm and 100 mm × 100 mm, have been built to map soft cosmic X-rays. The counters are constructed with a large drift region which allows us to use the center-of-gravity technique to improve the counter's efficiency and position resolution. Using 330 Torr of propane as the gas fill and an anode plane composed of 20 µm diameter, gold-plated tungsten wire spaced 1 mm apart, we have achieved a position resolution of better than 280 µm (FWHM) in two orthogonal directions at an X-ray energy of 0.94 keV. Copyright © 1978 by The Institute of Electrical and Electronics Engineers, Inc.