The 4D Camera: An 87 kHz Direct Electron Detector for Scanning/Transmission Electron Microscopy

Peter Ercius; Ian J Johnson; Philipp Pelz; Benjamin H Savitzky; Lauren Hughes; Hamish G Brown; Steven E Zeltmann; Shang-Lin Hsu; Cassio C S Pedroso; Bruce E Cohen; Ramamoorthy Ramesh; David Paul; John M Joseph; Thorsten Stezelberger; Cory Czarnik; Matthew Lent; Erin Fong; Jim Ciston; Mary C Scott; Colin Ophus; Andrew M Minor; Peter Denes

doi:10.1093/mam/ozae086

The 4D Camera: An 87 kHz Direct Electron Detector for Scanning/Transmission Electron Microscopy

Microsc Microanal. 2024 Sep 19:ozae086. doi: 10.1093/mam/ozae086. Online ahead of print.

Authors

Peter Ercius¹, Ian J Johnson², Philipp Pelz¹, Benjamin H Savitzky¹, Lauren Hughes¹, Hamish G Brown¹, Steven E Zeltmann³, Shang-Lin Hsu³, Cassio C S Pedroso⁴, Bruce E Cohen^{4

5}, Ramamoorthy Ramesh^{3

6

7}, David Paul⁸, John M Joseph², Thorsten Stezelberger², Cory Czarnik⁹, Matthew Lent⁹, Erin Fong², Jim Ciston¹, Mary C Scott^{1

3}, Colin Ophus¹, Andrew M Minor^{1

3}, Peter Denes¹

Affiliations

¹ National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
² Division of Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
³ Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720, USA.
⁴ Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁵ Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁶ Division of Materials Science, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁷ Department of Physics, University of California Berkeley, Berkeley, CA 94720, USA.
⁸ National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁹ Gatan Inc., Pleasanton, CA 94588, USA.

PMID: 39298134
DOI: 10.1093/mam/ozae086

Abstract

We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel active pixel sensor for scanning/transmission electron microscopy which operates at 87,000 Hz. The detector generates data at ∼480 Gbit/s which is captured by dedicated receiver computers with a parallelized software infrastructure that has been implemented to process the resulting 10-700 Gigabyte-sized raw datasets. The back illuminated detector provides the ability to detect single electron events at accelerating voltages from 30 to 300 kV. Through electron counting, the resulting sparse data sets are reduced in size by 10--300× compared to the raw data, and open-source sparsity-based processing algorithms offer rapid data analysis. The high frame rate allows for large and complex scanning diffraction experiments to be accomplished with typical scanning transmission electron microscopy scanning parameters.

Keywords: 4D-STEM; active pixel sensor; direct electron detector; phase contrast STEM; scanning transmission electron microscopy.