Ion-emitting molten glasses - silica gel revisited

A Bi^- ion emitter has been developed and studied which is modeled on the silica gel matrices that have been used to produce ions from a variety of elements such as Pb, Ag and Te for isotope ratio measurements. Studies with this model system demonstrate that this ion emitter is a liquid glass and that ion emission originates from the surface of the liquid glass. The large difference in ion emission observed with the use of different refractory metal filaments to support this silica gel type matrix is shown to be due to the extent to which the refractory metal is dissolved by the liquid glass, altering the properties of the glass, which in turn alters the ion emission properties. It is not due to the variation in work function of the refractory metal support filaments, as had been suspected. Additional types of study will have to be conducted in order to understand the mechanism of ion emission from the surfaces of these molten glasses.