### Issues

## Application of unified methodology for analytical calculation of absorbed dose gamma-radiation fractions to cylinder-shape biological objects

«Radiation and Risk», 2023, vol. 32, No. 1, pp.61-71

*DOI: 10.21870/0131-3878-2023-32-1-61-71*

**Authors**

**Sazykina T.G.**– Chief Researcher, D. Sc., Phys.-Math.

**Kryshev A.I.**– Head of Lab., D. Sc., Biol. RPA “Typhoon”. Contacts: 4 Pobedy str., Obninsk, Kaluga region, Russia, 249038. Tel.: +7(484)39-7-16-89; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. .

Research and Production Association “TYPHOON”, Obninsk

**Abstract**

The paper presents results of application of unified methodology for analytical evaluation of absorbed radiation fractions for dosimetry of cylinder-shape bioobjects following the internal uniform contamination with emitted photons. New models have been used for calculation of photon fractions dose absorbed by various non-human biological objects of various cylinder configurations and sizes. Evaluated absorbed photon radiation doses are in accordance with independently tested data, obtained by numeric integration of basic absorbed photon radiation dose with account of the cylinder volume. The theoretical interpretation of used calculation formulae based on the theory of middle chords in convex bodies is given in the paper. An advantage of the unified method is the possibility to use simple algebraic formulae for calculating absorbed radiation dose fractions in convex bodies (spheres, ellipsoids, cylinders) without the use of Monte Carlo computer programs and adjustment parameters. In contrast to the known European computer complex ERICA Tool the developed method of calculation of radiation doses to cylinder shape bio-objects may be also used for dosimetry of non-human species, for express-assessment of radioecological situation in radionuclide-contami-nated areas, as well as for radiation protection of biota.

**Key words**

*radiation dosimetry, internal exposure, photon absorbed fractions, Monte Carlo, soft-tissue cylinders, unified methodology, rescaling, unitless effective radius, analytical model, dose assessment, nuclear medicine, biota, environment.*

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