Background: Although the measurement of neutron dose equivalent was initiated several decades ago

the accuracy of the measurement is not high enough due to the dosimeter’s sensitivity and fluence response. Purpose: The aim of this work is to accurately scale the performance parameters and insure the design accuracy of neutron dose equivalent instrument. Methods: MCNP5 was used for simulation analysis of the impact of air

walls

and paraffin in the laboratory respectively on the barrels of neutron counting before experiment. Results: The experimental results show that under ideal conditions

the neutron counting rate decreased with the increase of distance between the source and probe. The air impact on neutron count was up at first and then became weakened

but tended to be strengthened again finally. The neutron scattering rate was less than 10%. And the shorter the distance was

the weaker became air scattering neutrons impact on probe counting. When the probe and the source distance reached 260 cm

the influence of the paraffin barrels was the weakest

which was 1%. The influence of the wall on the neutron count increased with the source-probe distance. When the probe and the source distance was 360 cm

the neutron scattering from the wall was 2 times of that from the source. When the source and the probe distance was 175 cm

all of influences to the neutron scattering reached the minimum

and the measurement data tended to be the most accurate. Conclusion: Through the comparison between experimental and theoretical data

the error of the count rate is less than 30% when the source and the probe distance is between 125–300 cm

confirming with the requirements of the neutron dose measurement technology

which verifies the accuracy of the neutron dose equivalent instrument design. Abstract