Neutron Captureγ-Rays from Scandium, Vanadium, Manganese, Cobalt, and Copper

The neutron capture γ-ray spectrum from scandium consists of an exceptionally large number of γ-rays, and those of highest energy are only partially resolved when the line width in the coincidence spectrum is 130 kev. The γ-ray corresponding to the direct transition to the ground state in Sc⁴⁶ (8.85±{}0.08 Mev), if correctly identified, has an intensity of 0.3 photon per 100 captures. Vanadium produces several strong γ-rays with intensities of about 10 photons per 100 captures. Of these, the γ-ray with the highest energy, 7.305±{}0.007 Mev, can be identified with the transition to the ground state of V⁵². A group of partially resolved γ-rays with energies between 7.6 and 8.0 Mev are tentatively ascribed to capture in the rare isotope V⁵⁰. If this interpretation is correct, the isotopic capture cross section of V⁵⁰ probably lies between 40 and 400 barns. The transition to the ground state in V⁵¹ was not detected. In manganese the transition to the ground state (7.261±{}0.006 Mev) is stronger than any other γ-ray in the spectrum (12 photons per 100 captures). With a line width of 100 kev it is only partially resolved from another strong γ-ray with an energy of 7.15±{}0.02 Mev. The remainder of the manganese spectrum is complex. From cobalt, about six γ-rays are produced each with intensities of the order of 5 photons per 100 captures. The γ-ray with the highest energy (7.486±{}0.006 Mev) may be identified with either the transition to the ground state or to the isomeric state at 59 kev. The copper spectrum is dominated by the strong γ-ray producing the ground state in Cu⁶⁴. Its energy is 7.914±{}0.006 Mev and its intensity is 24 photons per 100 captures in Cu⁶³. Another strong γ-ray at 7.634±{}0.006 Mev may be the transition to the ground state of Cu⁶⁶.