Abstract: While high heat is generated in the anode section in the gas discharge tube in accordance with the present invention during its use, the heat is transmitted to the stem by way of the anode support plate due to a configuration in which the anode support plate abuts against the stem, and is released outside from the stem, whereby the cooling efficiency of the anode section is improved. Since the anode section employs not a floating structure including stem pins interposed therein but a configuration in which it is seated on the stem by way of the anode support plate, the anode section is stabilized on the stem, whereby the resistance to vibration improves. Also, for assembling the anode section into a sealed envelope, it will be sufficient if the anode support plate is mounted on the stem, which contributes to improving the easiness in assembling the gas discharge tube.

Abstract: A hollow cathode discharge device loosely supported by a cathode lead-in 26 in a glass sleeve 32, the device including a ceramic shield 42 received in the rim 38 of the glass sleeve in freely slidable relation thereto, and maintained in position by holding means such as a mica disc 48 supported from the anode structure including an anode lead-in 30.

Abstract: A neutron accelerator tube having a target section, an ionization section, and a replenisher section for supplying accelerator gas to the ionization section. The ionization section is located between the target and the replenisher section and includes an ionization chamber adapted to receive accelerator gas from the replenisher section. The ionization section further includes spaced cathodes having opposed active surfaces exposed to the interior of the ionization chamber. The active surface of at least one of the cathodes is formulated of a .beta..sup.- emitting material. An anode is located intermediate the cathodes whereby in response to an applied positive voltage, electrons are transmitted between the opposed active surfaces of the cathodes and produce the emission of secondary electrons. The active surface of the other cathode may be formulated of a .beta..sup.- ray emitter or of material having a secondary electron emission factor of at least 2.

Abstract: A cyclotron suitable for use in neutron therapy, and comprising a pair of opposed, spaced pole shoes having their adjacent inner surfaces defining an accelerator zone, an electromagnetic coil system, at least one hollow accelerating dee electrode positioned in the accelerator zone, and having a radio-frequency resonator associated therewith, a magnet yoke shaped to substantially enclose the accelerator zone and constitute a neutron attenuation shield for neutrons produced in the cyclotron, a vacuum chamber enclosing the accelerator zone and each dee electrode, means for providing charged particles for acceleration within the accelerator zone, a target zone for a target device, and a neutron beam outlet in the magnet yoke for emission of a neutron beam produced in the cyclotron. The cyclotron includes auxiliary neutron shield means in the forward peak zone of a neutron beam produced in the cyclotron to attenuate neutron and gamma radiation in the forward peak zone to a patient tolerable level.