Multiple alanine pellet dosimeter: Design and first test results

Abstract

Existing nuclear accident dosimeters are based on the activity measurements of the neutron activation products. Those dose measurements require the use of expensive counting equipment. The other significant problem of existing accident dosimeters is that they need to be analyzed in a very short period, due to the short half-life of the activated products. The crystalline L-α-alanine is a well-known material for Electron Paramagnetic Resonance (EPR) dosimetry. It is widely used in radiation laboratories for both reference and transfer dosimetry. Alanine pellets are made from L-α-alanine powder mixed with 10–20% of a binder. The L-α-alanine pellets have ideal dosimetric properties. Alanine is sensitive to alpha, photon, and neutron irradiation. Until recently there was no way to distinguish separate dose contributions from multiple types of radiation. To overcome this shortfall, the multiple alanine pellet holder has been proposed, designed, and tested. It contains cadmium, lead, and ⁶LiF filters. The proposed approach allows for the separation of photon and neutron dose contributions. Use of the developed holder can also reduce negative effects of humidity and direct sun light on the alanine dosimetric properties. The developed holder design can be produced by a 3D printer at a low cost. Here we present and discuss the design and test results of the multiple alanine pellet dosimeter.