Using the Medipix3 detector for direct electron imaging in the range 60keV to 200keV in electron microscopy

TL;DR

This study evaluates the Medipix3 hybrid pixel detector's performance for direct electron imaging in a TEM across 60-200 keV, focusing on MTF and DQE measurements to assess its imaging capabilities.

Contribution

It provides new experimental data on Medipix3's imaging performance at various electron energies in TEM, demonstrating its potential for electron microscopy.

Findings

Measured MTF using knife edge technique at different energies

Determined DQE through noise power spectrum analysis

Assessed detector's suitability for direct electron imaging

Abstract

Hybrid pixel sensor technology such as the Medipix3 represents a unique tool for electron imaging. We have investigated its performance as a direct imaging detector using a Transmission Electron Microscope (TEM) which incorporated a Medipix3 detector with a 300 micrometre thick silicon layer compromising of 256x256 pixels at 55 micrometre pixel pitch. We present results taken with the Medipix3 in Single Pixel Mode (SPM) with electron beam energies in the range, 60 to 200 keV. Measurements of the Modulation Transfer Function (MTF) and the Detective Quantum Efficiency (DQE) were investigated. At a given beam energy, the MTF data was acquired by deploying the established knife edge technique. Similarly, the experimental data required to DQE was obtained by acquiring a stack of images of a focused beam and of free space (flatfield) to determine the Noise Power Spectrum (NPS).