METHOD FOR MEASURING URANIUM ENRICHMENT Russian patent published in 2012 - IPC G01N23/00 

FIELD: analysis of nuclear materials.

SUBSTANCE: photon radiation of the tested sample and the counting rates I₀ and I₁ are measured for the gamma-radiation line of ²³⁵ U with the energy of 185,7 keV and the distinctive X-ray emission line U Kα₁, the counting rate is measured for gamma-emission lines which occur during the fission of ²³⁵U, with energies higher and lower the line U Kα₁ (98,4 keV). The detection efficiency correlation is calculated for gamma-emission lines of ²³⁵ U and the line with energy of 185,7 keV, the approximation of received correlation values for detection efficiency defines the ratio η₁ of the detection efficiency for line U Kα₁ and the line with energy of 185,7 keV, while the uranium enrichment R is defined by soling the following equation:

aR²-[a-b-(c/η₁)(I₁/I₀)]R-b=0

where R is uranium enrichment; a, b, c are the constant coefficients; η_1- is the ratio of detection efficiencies for the line U Kα₁ and the line with energy of 185,7 keV; I₁ and I₀ are the measured counting rates for the line U Kα₁ and the line with energy of 185,7 keV.

EFFECT: improved uranium enrichment measurement.

1 dwg, 2 tbl