Estimation of the contribution of scattered ionising radiation to the dosimeter readings during measurements inside a low-background chamber

  • Aleksei A. Zaharadniuk Atomtex, 5 Hikala Street, Minsk 220005, Belarus https://orcid.org/0000-0003-2806-0817
  • Roman V. Lukashevich Atomtex, 5 Hikala Street, Minsk 220005, Belarus
DOI: https://doi.org/10.33581/2520-2243-2022-1-98-108

Abstract

The article evaluates the contribution of ionising gamma radiation scattered by structural materials when measuring the dose rate in a low-background chamber. The contribution of scattered radiation to the total dose rate was estimated using Monte Carlo simulations. A model of a low-background camera and a BDKG-05K dosimeter was created in the computer program Fluka. In addition, a model of a point source of 137Cs gamma radiation was placed in the low-background chamber. The fraction of scattered radiation was calculated by comparing the dosimeter readings when measuring the dose rate inside the low-background chamber with the reference model (the dosimeter model is placed together with the source in a vacuum, as a result, scattered radiation is completely absent). The calculation was carried out for two positions of the dosimeter relative to the source (30 and 100 cm). It was found that the contribution of scattered radiation to the dose rate reaches 38 % (distance from the source to the detector is 100 cm). To minimise the contribution of scattered radiation to the readings of the dosimeter, a design in the form of a collimator, inside which the source is located, was considered. Additionally, the work investigated the dependence of the dose rate formed by the scattered radiation on the design features of the collimator. It was found that the use of a collimator makes it possible to reduce the contribution of scattered radiation to 3 %. The aim of the work was to calculate the optimal design of the collimator, in which the contribution of scattered radiation to the total dose rate will be minimal. The results of the work will be used to create a prototype of a low-background camera and an optimised collimator.

Author Biographies

Aleksei A. Zaharadniuk, Atomtex, 5 Hikala Street, Minsk 220005, Belarus

engineer of the 2nd category at the dosimetry sector

Roman V. Lukashevich, Atomtex, 5 Hikala Street, Minsk 220005, Belarus

head of the dosimetry sector

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Published
2022-01-27
Keywords: Monte Carlo modelling, Fluka, low-background chamber, ionising radiation, dosimetry, scattering radiation
How to Cite
Zaharadniuk, A. A., & Lukashevich, R. V. (2022). Estimation of the contribution of scattered ionising radiation to the dosimeter readings during measurements inside a low-background chamber. Journal of the Belarusian State University. Physics, 1, 98-108. https://doi.org/10.33581/2520-2243-2022-1-98-108
Issue
No 1 (2022): Journal of the Belarusian State University. Physics
Section
Physics of Radiation Dosimetry

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