[en] Investigations of copper neutron-activation detectors which permitted to improve measurement accuracy of induced activity have been carried on. ⁶³Cu(n, γ)⁶⁴Cu activation reaction rate for copper detectors was compared with ¹⁹⁷Au(n, γ)¹⁹⁸Au reaction rate for which nuclear-physical characteristics are the most reliable. Activation detectors in the form of discs of 10 mm diameter and 25 and 100 μm thickness for copper and 3 μm for gold were used in the experiments. Detectors were simultaneously irradiated in thermal neutron fields. A number of measurements with copper detectors protected with 0.9 and 1.5 mm thick aluminium screens were carried out. Screens were placed at 5 and 10 cm distances from a scintillation unit. A value eta is suggested to be equal 0.343 on the basis of experimental results instead of 0.368 value earlier recommended (eta-quantum yield per one act of ⁶⁴Cu nuclide decay). A correction coefficient value taking account of absorption in the screen should be taken equal to 1.02 for 0.9 mm thick aluminium screen. ⁶³Cu(n, γ)⁶⁴Cu reaction cross section turned out to be equal to 4.50+-0.05 bar

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[en] The means and the methodical procedures applied during the attestation of the first in USSR neutron sample source on the basis of a vertical channel with a neuclear reactor, type MR in the ''I.V. Kurchatov'' atomic energy institute are described. The main testified value was the relation between the effective density in the thermal neutron flux and the monitor indication, registered with an error of 4,5% and a confidence coefficient of 95%. The sample source was used to graduate DPZ with an error of 5% and the same confidence coefficient

[en] Method of neutron activation weighing used for certification of neutron activation detectors is described. It is shown that for its realization the fund of initial specimens (FIS) including sets of initial specimens of different types together with necessary normative technical documentation is required. Basic requirements to FIS and its separate specimens are given, fabricating methods of the initial specimens decreasing considerably their certification error are considered. A concrete certification procedure of serial neutron activation detectors by means of the FIS initial specimens is described as well. It is noted that FIS is included in a special state standard of units of neutron flux and neutron fluence for nuclear physical devices

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