Energy weighting in a 2D-MHSP x-ray single photon detector

The 2D-MicroHole and Strip Plate (MHSP) is a simple single photon counting detector for x-ray imaging. It is a micropattern gas 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 point can be determined, but also the energy of individual photons. The detector energy resolving capability offers the possibility of obtaining three types of images: Integrating, Counting and Energy Weighting. The intensity of each pixel is obtained by adding the energy of each event, at the first case, by counting the number of events in the second one, or by adding each event weighted by a factor that depends on its energy, at the third case. Preliminary 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. For the present studies, a PVC step phantom is irradiated with a 20kV copper anode x-ray tube. A enhancement study of the Contrast and image quality between different techniques as a function of energy windows will be presented.