Evaluation of the relative radiation sensitivity of alanine to alpha radiation by electron paramagnetic resonance spectroscopy

«Radiation and Risk», 2016, vol. 25, No. 1, pp.76-84

Authors

Khailov A.M. – Senior Researcher, C. Sc., Biol. A. Tsyb MRRC, Obninsk, Russia. Contacts: 4 Korolyov str., Obninsk, Kaluga region, Russia, 249036. Tel.: (484) 399-71-48; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. .
Ivannikov A.I. – Lead. Researcher, C. Sc., Phys.-Math. A. Tsyb MRRC, Obninsk, Russia.
Skvortsov V.G. – Head of Lab., C. Sc., Biol. A. Tsyb MRRC, Obninsk, Russia.
Orlenko S.P. – Researcher. A. Tsyb MRRC, Obninsk, Russia.
Stepanenko V.F. – Head of Lab., D.Sc., Biol., Prof. A. Tsyb MRRC, Obninsk, Russia.
Suriyamurthy N.¹ – Lead. Researcher, C. Sc., Chem. Indira Gandhi Center for Atomic Research, Kalpakkam, India.

Abstract

Using ESR spectroscopy the relative radiation sensitivity of alanine to alpha radiation with respect to the standard gamma-ray ⁶⁰Co source was assessed. The results of the evaluations have shown that radiation-chemical yield of free radicals in alanine by gamma radiation is 1.5±0.2 times higher than that by alpha radiation source ²³⁹Pu with an energy of 5.14 MeV. The study of absorbed dose formation of alpha radiation in a standard alanine dosimeter having the shape of a cylindrical tablet with a diameter of 4.8 mm and a height of 2.9 mm when irradiated at the surface of a flat source was made using Monte Carlo calculations. It was shown that the majority of registered dose of alpha radiation by EPR spectroscopy is caused by paramagnetic centers formed in a thin layer bordering the source with a thickness not exceeding the maximum range of the alpha particles (a few tens of micrometers). However, about 40% of the total dose in the dosimeter tablet of the given size during irradiation was due to the alpha particles emitted by the adjacent to detector areas of the source that hit the lateral surface of the detector. The calculated data were confirmed experimentally by estimating the reduction of the signal after the mechanical removal of the contact layer and the layer from the side surface of the alanine dosimeter.

Key words
Аlanine, EPR spectroscopy, alpha radiation, plutonium-239, gamma radiation, range of the particles, radiation-induced radicals, radiation sensitivity, Monte Carlo method, dose profile.

References

Full-text article (in Russian)