The neutron dose and energy spectrum outside a 20-MV accelerator treatment room.
A maze design is discussed for a Therac 20 linear accelerator (manufactured by Atomic Energy of Canada, Ltd.) which reduces the flux of neutrons at the door to permissible levels in controlled areas. The L-shaped design allows for a relatively light door at the end of the maze, consisting of 5.08-cm (2-in.) borated polyethylene and 2-mm lead. A comparison is made between the neutron dose equivalent (DE) calculated by various methods and the DE measured with a variety of portable neutron survey meters. In addition, the neutron energy spectrum outside the maze at 1 m from the door, measured with a polyethylene multisphere LiI system, is reported.
D006801:Humans; D009502:Neutrons; D010315:Particle Accelerators; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011835:Radiation Protection; D011882:Radiotherapy, High-Energy