Edge-on detectors with active edge for X-ray photon counting imaging

The paper describes fabrication and testing of X-ray silicon edge-on detectors with active edge. In the edge-on strip detector configuration the photons are impinging on the chip edge and is absorbed parallel to the strip. The longer absorption length results in much higher quantum efficiency than face-on detectors (front-lluminated). To extend the sensitivity to ≤ 5keV the guard ring at one edge is replaced by an active edge made by 3D-processing. Test results with ²⁴¹Am and ⁵⁷Co sources are presented. Also it is shown that increasing the thickness to 2mm increases the efficiency at 122keV due to increased contribution from Compton events.