Sulphur Hexafluoride - Its Properities and Use as a Gaseous Insulator in Van De Graaff Acclerators

Investigations into the use of sulphur hexafluoride as an insulating gas for Van de Graaff accelerators have resulted in the decision to use it in the MP tandem accelerator presently being installed at Chalk River. Observations on a 3 megavolt vertical Van de Graaff and the EN 10 MeV tandem accelerator show that there are no problems due to the use of SF6 which cannot be solved with normal engineering procedures. An outline will be given of the physical and electrical properties, and a method of detecting and removing the corrosive breakdown products will be described. The gas handling system for the MP accelerator and a system for air removal will be described. An economic and functional comparison with a system using a 4:1 mixture of N2-CO2 is given.