Energy Weighting in a 2D-MHSP X-Ray Single Photon Detector

Abstract

The 2D-MicroHole and Strip Plate (MHSP) is a simple single photon counting detector for X-ray imaging. It is a micropattern gaseous detector having two orthogonal resistive lines crossing the amplification and readout electrodes on both sides of the MHSP for position detection. In this detector, not only the interaction position can be determined, but also the energy of individual photons. The detector energy resolving capability offers the possibility of obtaining three types of images of the intensity distribution: Integrating, Counting and Energy Weighting. In the first case, the intensity of each pixel is obtained by adding the energy of each event; in the second case, by counting the number of events and; in the third case, by adding each event weighted by a factor that depends on its energy. When a PVC step phantom is irradiated with a 20 kV copper anode X-ray tube, the results show a Contrast Enhancement up to 6% when Counting and Integrating images are compared and up to 20% when comparing Energy Weighting and Integrating images. A biological sample, a common quail wing, was also imaged. Studies of the Contrast Enhancement and image quality between different techniques as a function of energy windows are present.