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Title: Fabrication of compact electron gun for 6 MeV X-ray source

Conference ·

The 6 MeV X-Ray source for container cargo scanning application has been designed and developed by the Accelerator and Pulse Power Division, BARC, Mumbai. This compact linac has been designed as a mobile system, to be mounted on a moving container. In linac-based cargo-scanning system, to work electron gun on a movable container, it has to be robust. Electron gun is to work at 10{sup -7} mbar vacuum and 2000 degree Celsius temperature. An effort is made to engineer the gun assembly to make it more robust and aligned. The linac acts as the source of X-rays, which fall on the cargo and are then detected by the detector system. Many components are indigenously developed like grid, insulating ring, Tungsten filament and filament guide, which are made from alumina ceramic and Tantalum which is to work at 1500 degree Celsius. Filament connector is made from Invar to reduce heat loss and to make rigid connection. It was CNC machined and wire cut by EDM. Invar and Copper electrode feed through is shrink fitted with the help of liquid Nitrogen. Shrink fit tolerances of 15 micrometer are achieved by jig boring machining processes. Tantalum cup for LaB6 cathode and heat shield are made from die and punch mechanism. For alignment of electron emitter with beam axis this Tantalum cup is a crucial component. Electron gun is assembled and aligned its components with the help of precision jigs. The whole assembly was Helium leak tested by MSLD up to 4 x 10{sup -10} mbar.l/s vacuum, no leak was found. This paper will describe the machining, Tantalum cup forming, ceramic components development, heat shields, ceramic feed through etc of electron gun. (author)

Research Organization:
Bhabha Atomic Research Centre, Mumbai (India); Indian Vacuum Society, Mumbai (India)
OSTI ID:
22597173
Resource Relation:
Conference: ISDEIV-2014: 26. international symposium on discharges and electrical insulation in vacuum, Mumbai (India), 28 Sep - 3 Oct 2014; Other Information: Country of input: India; 2 refs., 11 figs.; This record replaces 48041801; Related Information: In: Proceedings of the twenty sixth international symposium on discharges and electrical insulation in vacuum. V. 2| 392 p.
Country of Publication:
United States
Language:
English