Shielding design calculations for beam dump facility of KOMAC

A project to construct the Korea Multi-purpose Accelerator Complex (KOMAC) is currently underway targeting a high-intensity proton beam with an average current of 4.8 mA. As for the first stage of construction, a 20 MeV linac is planned to be built by 2007 and additional DTL sections will be added to increase the proton energy to 100 MeV by 2012. In this paper, preliminary shielding estimates, such as the evaluation of the gamma ray and neutron dose rate around the beam dump, have been carried out with the three-dimensional (3-D) Monte Carlo transport code MCNPX in order to determine the shielding requirements. The tentative flux calculations using the 3-D deterministic code KATRIN, which can handle a coupled charged-neutral particle transport, were also performed and their results were compared with the MCNPX calculations. (authors)