Multistage charged particle accelerator, with high-vacuum insulation

A multistage charged-particle accelerator for operating with accelerating voltages higher than 150 kV comprising, in combination, a vacuum vessel;

• a relatively elongated high voltage insulator disengageably mounted on said vacuum vessel to extend thereinto;
• a Wehnelt cylinder and a source for producing charged particles mounted on the inner end of said high voltage insulator;
• an anode;
• means in said vacuum vessel supporting said anode in spaced relation to said source;
• said Wehnelt cylinder and said source constituting parts carrying the high voltages;
• a post-accelerating tube, containing stack-wise positioned post-accelerating electrodes, extending from said anode in said vacuum vessel;
• means, including a high voltage cable, supplying the operating potentials for said parts carrying the high voltage, said anode and said electrodes;
• said vacuum vessel having means for connection to a source of high vacuum for providing a high vacuum in said vessel to constitute the insulating medium for the parts carrying the high voltage;
• and at least one cylindrical screen in said vessel surrounding the parts carrying the high voltage and interposed between these parts and the vacuum vessel;
• said vacuum vessel functioning as a cylindrical screen.