Measurement of total cross-sections of natural Dy, In and Cu at the Pohang neutron facility

The Pohang Neutron Facility consists of an electron linear accelerator, a water-cooled Ta target, and an 11-m time-of-flight path which has been constructed for nuclear data production. It has been equipped with a new four-position sample changer controlled remotely by a CAMAC data acquisition system, which allows simultaneous accumulation of the neutron time of flight spectra from 4 different detectors. The neutron total cross-sections of natural Dy, In and Cu were measured in the neutron energy range from 0.1 eV to 100 eV by using the neutron time of flight method with the new data acquisition system. A 6LiZnS(Ag) glass scintillator was used as a neutron detector and metallic plates of natural Dy, In and Cu samples were used for the neutron transmission measurement. The neutron flight path from the water-cooled Ta target to the neutron detector was 10.81±0.02 m. The background level was determined by using notch-filters of Co, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements are in general agreement with the evaluated data in ENDF/B-VI. The resonance parameters of the Dy and In isotopes were extracted from the transmission data and compared with the previous ones. (author)