Measurement Of Yield Ratios For The Isomeric Pair Ce-137m,Ce-G In The Pr-141(Gamma, X)Ce-137m,Ce-G Reactions With Bremsstrahlung End-Point Energies Of 50-, 60-, And 70-Mev

We have measured the yield ratio of the high spin state to the low spin state of the isomeric pair Ce-137m,Ce-g produced in the Pr-141(gamma,x)Ce-137m,Ce-g reaction. The experiments were performed by irradiating three praseodymium foils with bremsstrahlung end-point energies of 50-, 60-, and 70-MeV. The induced activities of the Ce-137m and Ce-137g were measured by means of gamma-ray spectroscopy. The gamma-ray interference and the contributions of other radioisotopes to the measured activity of both the Ce-137m and Ce-137g were investigated and corrected. The obtained results are compared with the theoretical predictions using the computer code TALYS 1.8. The present results for the Pr-141(gamma,x)Ce-137m,Ce-g reaction were determined for the first time.