Potential for the use of a liquid activation circulation material to measure the neutron flux in a high gamma-ray background

The measurement of radiation fields in or near nuclear reactors is important for estimating radiation dose rates and damage, and for developing solutions for shielding problems. Such measurement mush be made in a difficult environment. Many types of detectors have been widely used in reactors to monitor the neutron flux. The activation detector is the most convenient, especially against a high gamma-ray background. In this study, liquid activation material is introduced to obtain a continuous measurement, and a rhodium solution is used to measure the reaction rate. There are three regions in this concept: the activation region, transfer or circulation region, and measurement or detection region. In this study, Rh2(SO4)3 with the concentration of 100 g/l is used as the solution. To obtain the maximum reaction rate, an optimum flow rate of 80 cm3/s was applied. Results showed a maximum counting rate in the equilibrium condition of about 18.6 cps. We conclude that it is possible to use a liquid activation method to measure the neutron flux in a high γ-ray background.