FURTHER DEVELOPMENTS WITH GLASS DETECTORS FOR HEAVY IONS AND FISSION FRAGMENTS

A large number of glasses of different chemical composition has been investigated systematically to find energy detectors with high energy resolution for heavy ions or fission fragments. To determine the energy accurately by measuring the diameter or the area of the etch pits, it is necessary to have diameters as large as possible. For metaphosphate glasses, diameters up to 250 μm and an energy resolution of about 2 MeV have been obtained for fission fragments. There exists no mass or nuclear charge dependence for the heavier ions between Cl and U. Measurements for ions with energies up to 800 MeV show a decreasing diameter characteristic approaching the threshold ionization levels in the high energy range. Metaphosphate glasses are useful also in detecting multifission events. A four-prong event is shown by this technique.