Forum 09/24/2009

“Performance of the DDD as a Direct Electron Detector for Low Dose TEM”

Robert Bilhorn and Liang Jin – Direct Electron, LP

Interest in direct electron detection for low-dose applications in transmission electron microscopy has reached a high level as new products have recently been  announced, and promising results from prototypes have been released.  This presentation will discuss the important design criteria for direct detection systems, particularly highlighting the differences from CCD based systems, and will describe the system attributes, such as pixel size, frame rate, point spread function, and single electron sensitivity, from which the benefits of direct detection are derived.  Operation and performance of a new 12 megapixel Direct Detection Device (DDD) camera system will be described and compared with several of the more familiar CCD camera system configurations.  Common detector system figures of merit will be presented, and several preliminary examples of use in a microscope will be provided.  Particular emphasis will be given to strategies to overcome radiation damage induced lifetime issues that have plagued previous efforts at realizing direct detection.