Development of a large format direct detection device for three dimensional transmission electron microscopy
New imaging systems are crucial in improving transmission electron microscopy (TEM) for the investigation of the structure and function of biological systems from the molecular to the cellular scale. Presented in this dissertation is the characterization of a direct detection device (DDD) camera. Also presented is an exploration of some of the TEM imaging applications of this camera. The DDD is a monolithic active pixel sensor that directly records the energy deposited by an incident electron. The camera that will be discussed is, to date, the largest prototype developed by the Xuong group at UCSD, with a 1024x1024 pixel array format. Unique features of the DDD are presented that allow for a variety of measurements and image processing not possible with the standard CCD camera systems typically used for TEM. A characterization of this detector has been performed, including the measurement of the modulation transfer function, the normalized noise power spectrum, and the detective quantum efficiency. The results of these measurements show that it is capable of high resolution, wide field imaging. Tomography and 2D imaging experiments using epoxy embedded thin sections of Drosophila cells infected with flock house virus as the test specimen were performed with a 120keV TEM. The results of tomography and 2D imaging experiments with the large format DDD provide compelling evidence that this system offers a powerful new tool for gathering meaningful information about biological specimen.