The influence of partial peak width integration on the statistical error has been investigated. It has been shown that integration of the central photopeak part —±(0.55–0.64) FWHM for narrow peaks and ±(0.50–0.53) FWHM for wide peaks-allows to decrease the statistical error 1.5–2.0 times in comparision with the TPA method. The results obtained are valid both for real photopeaks and for smoothed spectra. The theoretical results have been confirmed by experimental data.
A method for the determination of oxygen based on the reaction16O(n, p)16N is suggested. The samples are irradiated in stainless steel capsules with fast neutrons. The total neutron flux passing
through the sample is proportional to the flux passing through the wall of the capsule. Therefore, the activity induced in
the capsule according to the reaction56Fe(n, p)56Mn can be used to monitor the neutron flux through the sample. Thus, the necessity of maintaining the sample in an exact position
during the irradiation is eliminated.
A method is described for the determination of sodium and phosphorus using the NG-160 neutron generator and an automated pneumatic
transport device. The reactions23Na (n, p)23Ne and31P(n, α)28 Al are utilized for the determination of sodium and phosphorus, respectively. For the determination of sodium, hermetically
sealed vials are indispensable. The time required for one determination is 6 to 8 min. A rapid method for the determination
of macro-amounts of sodium against a phosphorus background is also described, leading to the general conclusion that isotopes
with γ-quantum energies close to 0.51 MeV can be determined against a background of positron radiation sources in a well-type
An instrumental procedure of activation analysis has been developed to study the distribution of some minor components in synthetic granates, ferrites and glass charges in some environmental materials. The determination of the degree of non-uniformity by NAA has been used for the preparation of uniform mixtures and for representative sample estimation in the analysis of nonhomogeneous materials.
For simplicity and unification of the comparator methods it is proposed to obtain a calibrating function of changing relative efficiency of registrating -radiation for any geometry of measurement (for any detector) from -spectrum comparator isotopes directly. In determining elements by their short- and medium-lived radionuclides the comparators52V and24Na were used. Biisotope comparator (65Zn,122Eu or182Ta) was used for long-lived radionuclides. The developed universal comparator method significantly simplifies the procedures for determining relative registration efficiencies of analytical lines of interesting radionuclides, thus reducing the labor and time requirements of analysis; this is very important in the case of a large scale NAA.
Authors:L. Smakhtin, L. Mekhryusheva, N. Filippova, N. Miglina, and T. Sinitsyna
A procedure is suggested of extraction-chromatographic pre-separation of REE's for the next activation determination. This method was applied for analyzing geological samples, underground and surface water, some technological materials.
Authors:I. Lisovskii, L. Smakhtin, N. Filippova, and V. Volgin
A semi-automatic pneumatic transport system for nuclear reactors is described. The sealed polyethylene capsules containing
the sample are placed into transport containers. Ten such containers are placed manually into a feeding device. All subsequent
operations (irradiation, removal of the capsule from the container, and transport of the capsule to the laboratory for activity
measurement) are automated. Total time from the completion of irradiation to the beginning of measurement is 10–20 sec.
Authors:L. Smakhtin, A. Kurinov, A. Merkulov, and U. Sinaysky
The uniformity of ferrit charge component distribution affects significantly the magnetic properties of the final products.
A characteristics feature of mixing efficiency is the concentration distribution of the components present in low concentration.
It was the aim of the present research to investigate the variants of the instrumental activation technique to measure cobalt,
sodium, and copper in ferrite charge. All data obtained were treated by the technique of the simple dispersion analysis. The
effect of some systematic errors on the statistical parameters under consideration have been studied. Means of quantitative
estimation of non-uniformity have also been discussed.
Authors:L. Smakhtin, A. Kurinov, A. Merkulov, R. Novgorodtsev, E. Schokel, N. Katargin, and A. Lisitsin
This paper describes simple algorithms for evaluating gamma-ray spectra, readily applicable to small computers. A comparative
assessment of the accuracy of the existing programs for experimental data analysis is presented. The use of “Nairi-K” computers
suitable for “on-line” operation with multichannel analyzers enables as many as 300 element determinations to be carried out
in a 7-hour working day.