MEASUREMENT OF GAMMA-RAY SPECTRA FROM THERMALNEUTRON CAPTURE

An investigation of the gamma-ray spectra of several isotopes from thermal-neutron capture has been carried out. The isotopes irradiated are Sc45, Ir191, Ir193, Rh103, Dy161, Dy164, and Ho165. The technique of using the bent crystal spectrometer has been refined by means of improved development of the photographic emulsion used as a detector, by means of a formalized datataking procedure and by the use of a digital computer to analyze the results in a consistent fashion. The instrument has been used to survey the low-energy photons from neutron capture by natural scandium, iridium and rhodium. A scintillation pair spectrometer is coupled to a twoparameter analyzer and has been used in coincidence studies of neutron-capture gamma rays from Dy161, Dy164 and Ho165. Its operation has been aided by the use of a digital computer to perform data reduction. An attempt has been made to perform stripping on the complex gamma-ray spectra obtained. The results have been compiled and nuclear energy level schemes have been proposed for Sc46, and somewhat tentatively for Dy165 and Ho166. Possible aditions to the present nuclear energy level schemes of Rh104 and Dy162 are also presented.