Charge-coupled devices in transmission electron microscopy

Roberts, Patricia T.E. (1980) Charge-coupled devices in transmission electron microscopy. PhD thesis, University of Glasgow.

Abstract

This thesis describes the results of experiments to test the suitability of charge-coupled devices (CCDs) for electron imaging. An electronic imaging system based on a CCD has several advantages over conventional imaging methods, particularly for image processing applications where quantitative data is required. The Introduction outlines the advantages of an electronic imaging system, and discusses available systems, and the possible merits of solid state devices, in particular CCDs. The operation of CCDs is described in Chapter 1, with particular reference to the Fairchild CCD 202, the device used in these experiments. The desirable properties for an imager with a quantitative output for computer processing are described in Chapter 3. In this chapter are reported the results of experiments to test the properties of the CCD 202 and these results show it to be suitable as a recording device for producing a quantitative output for image processing. It has a in the range of 0.46 - 0.6, has an output which is linearly related to the incident electron intensity, and has an electron gain of ~ 10[3] for 20 keV and ~ 10[4] for 60 and 100 keV electrons. An undesirable property of MOS devices such as CCDs is their limiter under exposure to ionizing radiation. Chapter 4 reviews radiation effects in MOS devices, presents results on experiments to test the CCD lifetime under irradiation, and discusses ways in which the useful life of the device can be extended. The output of the CCD is an analogue video signal, A Data Accumulation Unit was built to digitise and store the output signal and to transfer it to a computer or to magnetic tape for storage. In addition the image can be displayed on a CRT screen, and photographed to produce a permanent record. Chapter 5 describes the use of the CCD 202 to record electron images of various specimens and shows the images which were obtained. Chapter 6 summarises the findings on the suitability of CCDs for electron microscopy, and suggests modifications to the devices and to the imaging system which would extend the range of applications of CCDs.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > T Technology (General)
• Colleges/Schools: College of Science and Engineering
• Supervisor's Name: Chapman, Dr. J.N. and MacLeod, Dr. A.M.
• Date of Award: 1980
• Depositing User: Enlighten Team
• Unique ID: glathesis:1980-83067
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 02 Aug 2022 15:11
• Last Modified: 02 Aug 2022 15:11
• Thesis DOI: 10.5525/gla.thesis.83067
• URI: https://theses.gla.ac.uk/id/eprint/83067