Method for determining the emission intensity of gamma radiation from a radioelement

Abstract

A method for determining the intensity I(Ech1) of gamma radiation of a radioelement from the known intensity I(Ech2) of gamma radiation of a standard radioelement, characterised in that it includes a step for calculating the intensity I(Ech1) as the following formula, where S(Ech1) is the net area of the gamma radiation of the radioelement, S(Ech2) is the net area of the gamma radiation of the standard radioelement, R1 and R2 are respectively a total absorption efficiency of the radiation detector used for measuring S(Ech1) and of the radiation detector used for measuring S(Ech2), [Delta][rho]1 and [Delta][rho]2 are measurements of reactivity variation of a nuclear reactor measured by the oscillation technique, and relating respectively to the radioelement and the standard radioelement, WA,1 and WA,2 are respectively the neutron importance of the radioelement and the neutron importance of the standard radioelement, and Cd1 and Cd2 arerespectively a radioactive decay correction datum of the sample and a radioactivity decay correction datum of the standard sample.

Description

technical field [0001] The invention relates to a method for determining the gamma (γ) ray emission intensity of radioactive elements. Background technique [0002] The gamma-ray emission intensity of radioactive elements is an important data in several fields of reactor physics. They are used, for example, in non-destructive measurements (gamma spectrometry) or as input data for analog codes used to determine photon heating. [0003] A first method for determining the intensity of the gamma emission emitted by β-decay consists in using high-resolution spectrometry, for example, thanks to a germanium detector, obtained with extremely high precision (1% left and right), combined with relatively less well-controlled β-branch ratio data. Therefore, gamma emission data obtained by this first method often have an uncertainty higher than 10%. This is a practical disadvantage. [0004] A recently known method makes it possible to dispense with the determination of the β-branchi...

AI Technical Summary

Problems solved by technology

However, when determining gamma emission intensities, and in particular when normalizing these data, the precision obtained is highly related to the radioactive purity of the radionuclide species under study, which also constrains the uncertainty in the decay rate

Therefore, this method proved to be tricky to implement for short-lived radionuclides, on the order of minutes to hours, given the time required to prepare samples

This is also a practical disadvantage

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