Optimization of a neutron dosimeter for the high energy accelerators

In high energy accelerator facilities the neutron radiation should be continuously measured during operation to control the ambient dose. This requires a reliable neutron dosimeter in a wide energy range. In this work we present an optimization of a compact cylindrical passive neutron dosimeter based on thermoluminescence dosimetry (TLD) for the usage in wide energy neutron fields. In TLD devices, neutrons are detected via a ⁶Li(n, α)³H reaction whose cross section increases for low energy neutrons. To perform neutron fluence to equivalent ambient dose conversion an appropriate combination of a neutron moderator and absorber layouts should be used. The choice of materials and dimensions of different layers were tested with simulations using the FLUKA code. The final neutron dosimeter design improves the fluence-to-ambient dose conversion and provides almost angular independent equivalent dose reading. The dosimeter response covers almost 12 orders of magnitude of neutron energies which is rather sufficient for using it at high energy accelerators