Current status of the AGS spallation target experiment

In preparation for the construction of next-generation neutron sources, a series of experiments were performed using a mercury target assembly with a water moderator and a lead reflector at the ACS accelerator. In a bare target experiment, neutron spatial and energy distributions around the target were obtained at proton energies of 1.6-24 GeV using an activation method. The radioactivities induced in activation samples placed around the mercury target were also measured. Using a mercury target with a water moderator and a lead reflector, the spectral intensity of slow neutrons from the moderator was measured with only a few proton pulses with a newly developed technique, a current mode time-of-flight detector. A shielding experiment was also carried out to measure neutron attenuation in lateral shields of ordinary concrete and steel. This paper reviews the experimental results and the current status of the analyses. (author)