Measurements of neutron and photon distributions by using an activation technique at the Pohang Neutron Facility

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, was constructed to measure neutron total cross-sections in the neutron energy region from thermal to several hundreds of eV by using the time-of-flight method. In order to utilize this pulsed neutron facility based on an electron linac, we have to understand the characteristics of the radiation fields produced in this facility. We used the multiple-foil activation method to measure the neutron and the photon distributions produced by a water-cooled Ta target with and without the water moderator.X12