OSCILLATORY PATTERN OF DISTRIBUTION CS-137 IN THE BARK OF SCOTCH PINE

The paper studies the vertical distribution of Cs-137 trees in the bark of two model trees of Scots pine (Pinus sylvestris L.), selected in the zone of radioactive contamination of the Bryansk region. Each tree was divided into 10 centimeter bars from a length of up to 17 meters, after which the bark along with the bast was separated from each bar into a separate sample. In addition to Cs-137, the content of natural radionuclide K-40 was measured in the bark of model tree No.2 from a comline to 6.5 meters. Measurement of specific activity of technogenic radionuclide Cs-137 and natural radionuclide K-40 by gamma-spectrometric method. For the first time, it was found that in the bark of the studied trees, the vertical distribution of Cs-137 has a wave-like character and can be represented as harmonic oscillations with a period of 1 m. The distribution of potassium also has an oscillatory character similar to caesium, which is consistent with a similar mechanism of behavior of potassium and caesium in woody plants. The correlation coefficient between the values of specific activity of Cs-137 in model trees No.1 and No.2 was 0.80, and between Cs-137 and K-40 in model tree No. 2 was 0.45. Thus, Cs-137 can be used as a radiotracer to assess the intake and distribution of chemical elements in the tissues of scots pine. The found oscillatory nature of the vertical distribution of caesium and potassium in the pine bark has no analogues in the world literature.