Transmission of neutron and gamma radiation fields along the maze of a cyclotron vault

The neutron and gamma dose equivalent rates at various locations along the central plane of the four legged maze leading to the concrete vault of a 30 MeV Medical Cyclotron were measured. These measurements were performed during the bombardment of a water cooled aluminium target with a 30 MeV proton beam. The experimentally estimated neutron dose equivalent rates along the distance of penetration into the maze were fitted explicitly with a set of exponential functions. These functions were utilised to optimise the maze design calculations of similar cyclotron target caves.