Characterisation of the Medipix3 detector for 60 and 80 keV electrons

DOI: 10.1016/j.ultramic.2017.06.010

Authors: J. A. Mir (University of Oxford) , R. Clough (University of Oxford) , R. Macinnes (University of Glasgow) , C. Gough (University of Glasgow) , R. Plackett (University of Oxford) , I. Shipsey (University of Oxford) , H. Sawada (University of Oxford; Diamond Light Source; JEOL UK Ltd) , I. Maclaren (University of Glasgow) , R. Ballabriga (CERN) , D. Maneuski (University of Glasgow) , V. O'shea (University of Glasgow) , D. Mcgrouther (University of Glasgow) , A. I. Kirkland (University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Ultramicroscopy

State: Published (Approved)
Published: June 2017

Abstract: In this paper we report quantitative measurements of the imaging performance for the current generation of hybrid pixel detector, Medipix3, used as a direct electron detector. We have measured the modulation transfer function and detective quantum efficiency at beam energies of 60 & 80 keV. In single pixel mode, energy threshold values can be chosen to maximize either the modulation transfer function or the detective quantum efficiency, obtaining values near to, or exceeding those for a theoretical detector with square pixels. The Medipix3 charge summing mode delivers simultaneous, high values of both modulation transfer function and detective quantum efficiency. We have also characterized the detector response to single electron events and describe an empirical model that predicts the detector modulation transfer function and detective quantum efficiency based on energy threshold. Exemplifying our findings we demonstrate the Medipix3 imaging performance recording a fully exposed electron diffraction pattern at 24-bit depth together with images in single pixel and charge summing modes. Our findings highlight that for transmission electron microscopy performed at low energies (energies <100 keV) thick hybrid pixel detectors provide an advantageous architecture for direct electron imaging.

Journal Keywords: Medipix3; Single Pixel Mode; Charge Summing Mode; TEM, MTF; DQE; Nyquist Frequency

Subject Areas: Physics, Technique Development


Technical Areas: Detectors