A high intensity sputter negative ion source with multitarget positions and target scanners

The source is based on the principle put forward by Middleton, but modified significantly to a multifunction version for variant applications. It is equipped with a spherical molybdenum ionizer, an eight‐position target wheel, and a special Cs vapor nozzle. Due to the special design, target changing and scanning are carried out only by means of rotations, to simplify the mechanism and automatic control procedures. The tube for transmitting Cs vapor, as a resistance, is connected in series in the ionizer supply circuit to reach a high enough temperature for the vapor to pass. Details of the mechanical design, operation modes, and test results are given.