Properties of an imaging gas scintillation proportional counter

A parallel-grid gas scintillation proportional counter (GSPC), coupled to a multiwire proportional counter (MWPC) through a UV transparent window, yields a new instrument that combines the good energy resolution of the GSPC with the imaging capabilities of the MWPC. The imaging gas scintillation proportional counter (IGSPC) operates on the principle of detecting the centroid of the UV light generated by X-ray photons interacting in the noble gas of the GSPC with a UV sensitive gas [e.g. Tetrakis (dimethylamino) ethylene (TMAE)] in the MWPC. A prototype version of the counter has been built which yields a measured performance of 9% (fwhm) energy resolution and 0.9 mm (fwhm) spatial resolution at 6 keV. (orig.)