80 kV electrostatic wire septum for AmPS

In the extraction process of the Amsterdam Pulse Stretcher (AmPS) the extracted beam is intercepted from the circulating beam by the 1 m long electrostatic wire septum. For a bending angle of 4.4 mrad the maximum voltage is 80 kV. An innovative mechanical construction has been developed to create a wire spacing of 0.65 mm between tungsten wires of 50 μm diameter. Stainless steel spring wires, bent on a half cylindrical carrier, stretch the septum wires two by two. This insures that eventually broken wires are retracted. Care has been given to the electric field distribution at the contrance and exit of the septum and to the insulators, required to support the anode. Prototype tests have been successful up to an anode voltage of 120 kV. (author). 9 refs.; 5 figs