Electronic, mechanical and electron-optical engineering design features of the cambridge university 600 KV high resolution electron microscope

1. Introduction.The Cambridge University 600 kV high resolution electron microscope has been developed as a joint programme between the Department of Engineering and the Department of Physics. The shorter electron wavelength at 600 kV when compared to 100 kV gives a potential improvement in resolution that can only be realised in practice if the engineering design and construction are also correspondingly improved. Many aspects of this microscope have been developed specifically for this attempt at very high resolution. Some of these aspects were reported in September 1977 at the time when the microscope was first operated (Nixon et al. 1977). After three months operation the present resolution is better than 3 Å with no indication that any fundamental design limit has been approached.The following three items have been purchased outside. All other aspects of the microscope have been designed and constructed in Cambridge University. The high voltage generator and accelerator, as described by Reinhold and Gleyvod (1974), has been supplied by Haefely, Switzerland