Steps Towards Large Scale Production of High-Spin Hafnium Isomers by Spallation Reactions

摘要

This report results from a contract tasking Induced Gamma Emission Foundation as follows: The contractor will investigate the production and accumulation of the nuclear isomer 178m2 Hafnium by spallation of hafnium targets with high-energy protons. The Hafnium yield will be assayed and compared to predictions. The program will use Hf targets for the optimization of the 178m2Hf yield and for the minimization of the running cost related to the simplicity and availability of accelerators operating at such low energies. The operation cost for a small cyclotron that provides protons of energies around 150 MeV are order of magnitude lower than those for the operation of the Los Alamos 800 MeV meson factory facility. By the end of the first year the Foundation will have the results of the data analysis for the irradiation of the natural Hf targets and LAHET calculations will be recalibrated based on the new experimental data. The technical problems related to the design and mounting of Hf targets including heat removal solutions will be settled. Working from this base the Foundation will contract the irradiation of the enriched Hf targets at the Dubna synchrocyclotron establishing all the details concerning the beam energies, number of the irradiations and their duration.