Experience in designing the sealed electron waveguide linacs

The possibility of using a non-knock-down, sealed structure for a vacuum system of linacs is shown for developing electron accelerators for well-logging geophysical equipment. The basic specifications for the design and manifacture of sealed accelerators are given. 10 operating accelerating tubes have been manifactured according to the developed technology. The first samples of tubes were equipped with pressure gauge transducers which made it possible to monitor pressure 10-5 to 10-6 N/m2 inside a sealed device. The obtained vacuum assures stable accelerator operation: changes in the accelerated electron beam energy and current during a working day did not exceed 10%. The tubes are serviceable during several years, their service life being above 500 h. The accelerator size and weight are essentially reduced due to the sealed structure. The prestart-up time is reduced down to 3 to 5 min, the area occupied by the accelerator and the drained power decrease. High vacuum permits to use an oxide cathode with a high current density, die to which the electron beam diameter decreases and the beam focusing becomes easier. A conclusion is made on the applicability of sealed tructures in 6 to 7 MeV serial accelerators for industrial purposes