Ensuring the unity of measurements of the neutron radiation rate absorbed dose in the field of clinical neutron radiation dosimetry

Development of neutron radiation therapy arises the question of ensuring the uniformity of measurements of the absorbed dose and the absorbed dose rate of neutron radiation. FGUP “VNIIFTRI” improved the primary method and means of reproducing the unit of neutron radiation absorbed dose rate within the framework of improving the State primary standard of units of absorbed dose rate and neutron dose equivalent rate GET 117-2010. A set of ionization chambers has been created and the upper value of the reproduction of the unit of absorbed dose rate of neutron radiation has been expanded. A hardware-methodical complex has also been developed for transferring a unit of absorbed dose rate of neutron radiation to nuclear physics facilities used in neutron radiation therapy. As a result the expanded relative uncertainty of reproduction of the unit of absorbed dose rate does not exceed 3%, the expanded relative uncertainty of the transmission method does not exceed 0.5%. The resulting level of accuracy is in line with the recommendations used in neutron beam therapy.