Study On Measurement Of ～(182)Hf/～(180)Hf By Multi-collector Inductively Plasma Mass Spectrometry

¹⁸²Hf is an important radionuclide for nuclear diagnosis and study on supernov a explosions. The reference material of ¹⁸²Hf/¹⁸⁰Hf is especially important but not available. Regarding as the demands of nuclear study and engineering, a method has been developed to measure the ¹⁸²Hf/¹⁸⁰Hf with high-precision by using Multi-collector Inductively Plasma Mass Spectrometry (MC-ICP-MS).Theoretical arithmetic has been made to evaluate the interference of isobaric ¹⁸²W to the ¹⁸²Hf Based on the calculation with Origen2 programme, two schemes are proposed for measurement of ¹⁸²Hf/¹⁸⁰Hf to the needs of different chemical separation corresponding to different Hf/W and the changes of sample constitutions. Measurements of ¹⁸²Hf/¹⁸⁰Hfhave been finished after the chemical separation of Hf and W in scheme one and that of ¹⁸²Hf/¹⁸⁰Hf have been done directly followed by the aid of deducting the isobaric ¹⁸²W theoretically in scheme two.Anion exchange column is used to separate W from Hf. With Hf/W of 10 the decontamination factor for W is 100. When Hf/W is about in 10⁶ level, the main effects of chemical separation have been studied exploringly.The operating parameters of MC-ICP-MS have been studied and optimized, such as the adjustment of rate of nebuliser gas flow, torch position, RF frequency, the rate of collision gas flow and the various modes of ion extraction etc. Molecular interference, isobar interference, mass tail effect and mass bias have been studied.After deducting the interference of isobaric ¹⁸²W, the result of ¹⁸²Hf/¹⁸⁰Hf is (1.223±0.172)×10^-6.