A SOURCE OF NEGATIVE HYDROGEN IONS

A negative hydrogen ion source in which mercury vapor is used is described. From measurements made on the beam at various energies it was concluded that the optimum target thickness'' is(1 to 2) x 10/sup 15/ atoms/ cm/sup 2 /. The recharging coefficient is given as a function of energy. The optimum proton energy for recharging is 10 to 12 kv. (J.S.R.)