Using a 64Cu source to test SLICS

The short-lived isotope counting system (SLICS) being built for the OMEGA laser facility at LLE requires short-lived radioisotopes, such as 64Cu, for testing purposes. Using the SUNY Geneseo neutron howitzer, which contains a Plutonium-Beryllium (Pu-Be) source, 63Cu was bombarded with water moderated thermal neutrons to produce 64Cu via the 63Cu(n,gamma) capture reaction.The likelihood of neutron capture was increased using the optimal radial distance. Once activated, the 64Cu decays 61.6% of the time producing a positron with an endpoint energy of 653 keV which annihilates with an electron to produce two back-to-back gamma rays with energies of 511 keV each. The daughter product, 64Ni, is formed in the first excited state. It promptly decays to the ground state of 64Ni emitting a 1345 keV gamma ray which is used to determine the activity of the Cu source using the Gamma-X low background gamma-ray counting station. The activated 64Cu decays 38.5% of the time to 64Zn in the ground state, producing an electron with an endpoint energy of 579 keV. The 12.7 hour half-life of 64Cu allowed its transport to Houghton College where its signature was measured as a background to 66Cu used in future experiments to simulate detection of radioisotopes produced in an ICF implosion.