GB1328956A - Rotary target for electrostatic accelerator which operates as a neutron generator - Google Patents

Abstract

1328956 Targets for particle accelerators COMMISSARIAT A L'ENERGIE ATOMIQUE 18 Jan 1971 [20 Jan 1970 24 Sept 1970] 2264/71 Heading H1D A rotary target, e.g. for an electrostatic accelerator, comprises an annular target area 57 positioned to receive a beam of particles 59 and mounted on a rotor 51 which is in turn mounted on a rotatable shaft carried in at least one bearing, a stator surrounding the rotor and forming an end shield behind the target, means being provided for the circulation of a heat transporting fluid in the space between the end shield and the target, the circulation resulting from the centrifugal action of the rotor on the fluid and causing the fluid to pass through a heat exchanger 71, and at least one system of baffles 61, 63 between said rotor and said stator to prevent the fluid from contaminating the vacuum system of the accelerator. A liquid nitrogen trap 67 may be provided to further reduce contamination. The shaft may be mounted in ball bearings or a liquid bearing, in which case the liquid may be the coolant fluid, and the shaft may be driven through a pulley (23), Fig. 1 (not shown), or through magnetic coupling means 55. In Fig. 1 (not shown), the target consists of a hollow frustum of a cone, the target area (9) being on the inner surface of the base and the beam of particles (3) entering through the summit (5) of the frustum. A modified baffle system is illustrated in Fig. 3 (not shown), in which the stator is provided with toroidal cavities (81, 83) which are open towards the face of the rotor remote from the end shield and adjacent the circumference of the rotor, the openings of the cavities being non-coplanar and a corresponding step (61a) being provided in the rotor. The cooling liquid may be water, sodium or mercury. The target may be sheet copper 0À5 mm. to 1 mm. thick.