High resolution X-ray gas proportional detectors with delay line position sensing for high counting rates

A class of high resolution gas proportional X-ray detectors with delay line position readout is described. Positron resolution fwhm/l ≈ 1 to 2 × 10−3 for detector lengths l = 60 to 180 mm has been achieved at counting rates of ∼2 × 105s−1, with the best absolute resolution of ∼70 μm (fwhm) for 5 to 8 keV X-rays. Conditions for uniformity of photon detection efficiency, high position resolution and accuracy and high counting rates are discussed for detectors of different dimensions combined with an optimized delay line readout.