부산대학교 도서관

The yield of spallation products and the process of 660Mev proton interactions with hafnium nuclei are investigated. Yields of spallation products and beta /sup -/, beta /sup +/, and Kcapture isotopes were determined. For the K-capture isotopes the order of precision was 50 to 100%: The yield of isotopes as a function of their mass number was plotted. The spallation shows a cupola- shaped curve similar to that of copper spallation; however, the hafrium cupola is shifted towand neutron-deficient nuclei. Tabulated results show that the mean number of evaporated neutrons in hafnium spallation is 3.7 fold higher than the mean nuniber of neutrons evaporated from copper, while the number of evaporated protons is only 1.6 fold greater. A sharp increase in the number of evaporated neutrons is indicated for atomic numbers from 29 to 79, while the number of cascade neutrons remains stable (2 for copper and 2.5 for hafrium). The mean excitation energy for hafnium nuclei, found at 150 Mev, is in gocd agreement with published data. (R.V.J.)