Very-High Dynamic Range, 10,000 Frames/Second Pixel Array Detector for Electron Microscopy

Journal Article · 06 March 2022 · Microscopy and Microanalysis

DOI: https://doi.org/10.1017/S1431927622000174 · OSTI ID:1847972

Philipp, Hugh T. ; Tate, Mark W.; Shanks, Katherine S.; Mele, Luigi; Peemen, Maurice; Dona, Pleun; Hartong, Reinout; van Veen, Gerard; Shao, Yu-Tsun; Chen, Zhen ; Thom-Levy, Julia; Muller, David A. ; Gruner, Sol M.

Precision and accuracy of quantitative scanning transmission electron microscopy (STEM) methods such as ptychography, and the mapping of electric, magnetic, and strain fields depend on the dose. Reasonable acquisition time requires high beam current and the ability to quantitatively detect both large and minute changes in signal. A new hybrid pixel array detector (PAD), the second-generation Electron Microscope Pixel Array Detector (EMPAD-G2), addresses this challenge by advancing the technology of a previous generation PAD, the EMPAD. The EMPAD-G2 images continuously at a frame-rates up to 10 kHz with a dynamic range that spans from low-noise detection of single electrons to electron beam currents exceeding 180 pA per pixel, even at electron energies of 300 keV. The EMPAD-G2 enables rapid collection of high-quality STEM data that simultaneously contain full diffraction information from unsaturated bright-field disks to usable Kikuchi bands and higher-order Laue zones. Test results from 80 to 300 keV are presented, as are first experimental results demonstrating ptychographic reconstructions, strain and polarization maps. We introduce a new information metric, the maximum usable imaging speed (MUIS), to identify when a detector becomes electron-starved, saturated or its pixel count is mismatched with the beam current.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• Sponsoring Organization: NSF; USDOE
• Grant/Contract Number: SC0004079; SC0016035; SC0017631
• OSTI ID: 1847972
• Journal Information: Microscopy and Microanalysis, Journal Name: Microscopy and Microanalysis Journal Issue: 2 Vol. 28; ISSN 1431-9276
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United States
• Language: English