High precision mapping of single-pixel Silicon Drift Detector for applications in astrophysics and advanced light source

A Silicon Drift Detector with 3×3 mm2 sensitive area was designed by INFN of Trieste and built by FBK-Trento. It represents a single-pixel precursor of a monolithic matrix of multipixel Silicon Drift Detectors and, at the same time, a model of one cell Fluorescence Detector System (XAFS) for SESAME. The point-by-point mapping tests of the detector were carried out in the X-ray facilities at INAF-IAPS in Rome, equipped with a motorized two-axis micrometric positioning system. High precision characterization of this detector was done with a radioactive 55Fe source and a collimated Ti X-ray tube equipped with a Bragg crystal monocromator. The mapping in different positions and bias condition was specifically-aimed to the detailed analysis of the charge collection efficiency at the edge of the detector. The result is important to understand and verify the aspects related to the collection of the signal with respect to the position of interactions of the photons, especially in consideration of the new design and development of monolithic multipixel detectors.