Levels and gamma transitions of ⁴⁰K studied by neutron capture

The ³⁹K(n, gamma )⁴⁰K reaction has been studied with thermal neutrons using curved-crystal, pair and Ge(Li) spectrometers. In total, 427 gamma rays have been observed and 302 were placed in a level scheme containing 62 levels below 5100 keV with energy errors mostly less than 100 eV. Nine levels were observed for the first time in the (n, gamma ) reaction. New information on spins and parities was deduced from the detailed gamma branchings. The neutron binding energy was determined to be 7799.55+or-0.08 keV. The level scheme is compared with shell and statistical-model predictions.