Improved Energy Resolution Capability of an Imaging Proportional Counter Using Electron Counting Techniques

The number of electrons initially created by the absorption of a soft X-ray photon in a parallel plate proportional counter may be counted by detection of the fast light pulses emitted from the resulting electron avalanches. We show that good energy resolution may be achieved (~34% at C-K, 0.28 keV) with this technique. Using the light signal it is also possible to image events by means of an image intensifier, and position resolution of 350 μm FWHM at 0.28 keV has been achieved without event centroiding.