Direct and indirect signal detection of 122keV photons with a novel detector combining a pnCCD and a CsI(Tl) scintillator

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 805; pp. 55 - 62
• Main Authors: Schlosser, D.M., Huth, M., Hartmann, R., Abboud, A., Send, S., Conka-Nurdan, T., Shokr, M., Pietsch, U., Strüder, L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2016
• Subjects: CsI(Tl); Energy resolution; Hard X-rays; PnCCD; Spatial resolution; CsI(Tl); PnCCD; Hard X-rays; Energy resolution; Spatial resolution
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2015.08.065

By combining a low noise fully depleted pnCCD detector with a CsI(Tl) scintillator, an energy-dispersive area detector can be realized with a high quantum efficiency (QE) in the range from below 1keV to above 100keV. In direct detection mode the pnCCD exhibits a relative energy resolution of 1% at 122keV and spatial resolution of less than 75µm, the pixel size of the pnCCD. In the indirect detection mode, i.e. conversion of the incoming X-rays in the scintillator, the measured energy resolution was about 9–13% at 122keV, depending on the depth of interaction in the scintillator, while the position resolution, extracted with the help of simulations, was 30µm only. We show simulated data for incident photons of 122keV and compare the various interaction processes and relevant physical parameters to experimental results obtained with a radioactive 57Co source.
•Position and energy resolving pnCCD+CsI(Tl) detector for energies from 1-150 keV•Detection in the pnCCD (122keV): 1% energy and <75µm spatial resolution•Detection in the scintillator (122keV): 9-12% energy and ~30µm spatial resolution