Gatan US1000 CCD Camera with CM12

Chen Xu

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A Gatan Ultrascan CCD camera has been installed on CM12 since beginning of December, 2008. Similar to the Gatan US4000 CCD on Tecnai F30, this camera is also a 4-port readout optical stack. The MTF property of this camera on 120keV is significantly better than that of Gatan US4000 CCD on Tecnai F30 under 300keV. It is expected that it can replace electron films in most of applications that use CM12, since the image quality is comparable to that of film.

Unfortunately, due to the outdated version of CM12 firmware, DigitalMicrogaph doesn't communicate with our CM12. Therefore, when using DigitalMicrogaph to take image, one has to manually input magnification information from scope, if you want to have accurate scale bar shown in the image. Beside DigitalMicrogaph, a recent version of SerialEM has also been installed on this system. Although SerialEM is designed for Tecnai or JEOL system and to control them, it runs just fine on our CM12. It does provide flexibility and more options to drive the camera. It is recommended to use SerialEM to collect the data which is going to be processed, since, beside several other advantages, it also saves image directly into MRC format.

In this document, I first give you a couple of notes for using DigitalMicrogaph and SerialEM. Then, it lists a table for calibration of magnifications and exact pixel size on CCD. Finally, there is a section regarding electron dose.

You can also get pdf version of this document here.

Table of Contents
1 Some Properties of this Gatan US1000 CCD
2 Things that are needed to pay attention to
3 Note about DigitalMicrogaph
4 Note about Shutter control
5 Note about SerialEM
6 Monitor Drift Rate using SerialEM
7 Mag & Pixel Size Calibration table
8 Note about electron dose
9 Access CM12 Data Remotely
10 Remove X-ray and Unstack

1 Some Properties of this Gatan US1000 CCD

This is a 2k x 2k camera, with U type scintillator. Pixel size is 14um @ 2048 x 2048. 4 ports readout. MTF at 1/2 Nyquist frequency is about 0.16 at 120keV. Electron to counts Conversion Efficiency is 24 Counts/Prim e-. This is a 16-bit camera.