Vacuum system design

The Zeta I vacuum system consists of a toroidal tube of 42 in bore by 11 ft mean diameter fabricated from 1 in aluminium plate with a 48-section insulated interleaved water-cooled liner made from 1/8 in aluminium sheet. The torus was split vertically, each half torus being mounted on a trolley with its vacuum pumps and ancillaries, and arranged in such a way that the whole system could easily be withdrawn from the transformer core for servicing or modification. Experimental work in 1957 and 1958 was not seriously limited by vacuum techniques, since loss due to radiation from impurities in the discharge appears to have been only about 20% of the energy input, but it is unlikely that a significant increase in temperature will be attained unless impurities in the discharge can be reduced by one or two orders of magnitude.