The vacuum system of the University of British Columbia Van de Graaff generator and a mass spectrometer leak detector

The vacuum system of the Van de Graaff generator is described. Techniques in the construction of the high voltage vacuum tubes are indicated. The required performance of the system and the methods of attaining it are outlined, calculations being given in the Appendices. Vacuum pressure gauges are described and the indicated performance of the system recorded. Vacuum protection circuits are discussed. Methods of leak detection are discussed and the University of British Columbia mass spectrometer leak detector described in detail. The theory of analysis by a spectrometer with a coterminous crossed electric and magnetic field is given. An operating procedure for the spectrometer is described in detail and some results recorded and discussed.