[The depth distribution of neutron-capture events in 10B nuclei during the irradiation of a water phantom with neutrons from the channels of the BR-10 reactor]. / Glubinnoe raspredelenie neitron-zakhvatnykh sobytii na iadrakh 10B pri obluchenii vodnogo fantoma neitronami iz kanalov reaktora BR-10.

The authors present the results of experimental investigations of distribution of capture events on nuclei 10B by the depth of a water phantom during its irradiation with beams T-4 and B-3 of the BR-10 reactor. A ferrous sulfate dosimeter with added boric acid was used as a detector of such events. The depth of a water phantom on which the effect of boron capture by a neutron beam is decreased 2-fold, is 1.7 cm. For the B-3 beam a curve of depth correlation of neutron capture events had a broad maximum at a depth of 4-5 cm.

[The shape of the absorbed dosage in neutron irradiation of a water phantom]. / Formirovanie pogloshchennoi dozy pri obluchenii vodnogo fantoma neitronami.

The paper is concerned with the results of experimental and estimated investigations into the spatial distribution of an absorbed dose and the spectrum of neutrons during irradiation of a water phantom by a P-3 beam of a BP-10 reactor. The ratio of densely ionizing and rarely ionizing components of an absorbed dose as well as the ratios between neutrons of different energetic groups were shown to undergo considerable changes with the penetration of reactor neutrons into the depth of a tissue-equivalent medium. The obtained results serve as basic data in various biomedical investigations using reactor neutron beams, including the planning of their use in cancer therapy.

[Sensitivity to neutrons of heterogeneous ionization chambers]. / Chuvstvitel'nost' k neitronam geterogennykh ionizatsionnykh kamer.

The authors obtained theoretical and experimental data on the sensitivity to monochromatic and reaction neutrons of ionization chambers with different sizes of the air cavity between tissue equivalent walls. Significant difference of the sensitivity to neutrons of such heterogeneous chambers was noted as compared to that of homogeneous tissue equivalent ionization chambers. However proceeding from the results of the study we can determine with the precision of 10% the absolute absorbed doses in the dosimetry of biomedical investigations using neutrons of different energies.

[Use of photonuclear reactions for studying the biological action of slow heavy ions]. / Ispol'zovanie fotoiadernykh reaktsii dlia izucheniia biologicheskogo deistviia medlennykh tiazhelykh ionov.

Since ranges of low-energy heavy ions are too little the study of their action on cells is only possible using indirect irradiation, for instance, with neurons which form low--energy heavy ions uniformly inside a cell. In our studies we used photonuclear reactions which occur upon irradiation of a bio-object with high energy bremsstrahlung. The advantage of this method over the method based on the usage of neutrons has been demonstrated. The data are submitted obtained after exposure of yeast cells to photonuclear products.