Measurement of Total Cross Sections at Pohang Neutron Facility

Abstract

The Pohang Neutron Facility, which consists of an electron linear accelerator, a water‐cooled Ta target with a water moderator, and a time‐of‐flight path with an 11 m length has been operated since 2000. We report the status activities on the neutron total cross‐section measurements in the neutron energy region from 0.01 eV to 100 eV by the neutron time‐of‐flight method at Pohang Neutron Facility. A 6Li‐ZnS(Ag) scintillator with a diameter of 12.5 cm and a thickness of 1.5 cm has been used as a neutron detector. The background level has been determined by using notch‐filters of Co, In, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and that from neutron capture, we have employed a neutron‐gamma separation system based on their different pulse shape. The present measurements for Ag, Hf, and Ta samples are compared with the previous ones and the evaluated data in ENDF/B‐VI. The resonance parameters for Ag and Hf samples have been extracted from the transmission data by using the SAMMY ...