Mesure des isotopes du thorium dans l'eau de mer

Limite supérieure d’un embranchement α de l’UX1 (234Th)

Extraction par solvant d'elements cis et transuraniens a partir de nitrates alcalins fondus

A solvent extraction technique to separate different chemical species of thorium is presented. The products formed by the chemical effects of the /n,γ/ reaction on the Th/acac/4 were separated by this method and the retention value was measured.

Radiochemical separation of thorium acetylacetonate from other thorium species

A solution of Th-234 from Uranyle nitrate was prepared for the use as tracer of its α emitting isotopes Th-230, 228, 232.



The aim of the work was to obtain Th-234 containing as little as possible α emitting elements.



U was separated from Th by ether extraction.



The impurities present in the solution of Th-234 are: 



— U due to incomplete separation.




— Th-230 growing from U-234 and chemically inseparable frm U-234




— U-234 formed by desintegration of Th-230






The most favourable conditions for obtaining a solution of Th-234 with high radioactive purity are discussed.



The preparation of a Th-234 solution with a ratio αβ < 1,8 10−6 is described in detail. This solution can be used as radiotracer in measuring quantities of Th-230 (Ionium) as low as 10−11 g.

M. Nikolic

Papers

Préparation de Thorium‐234 (UX1) de haute pureté radioactive