Sisak Method Is Rapid Separation From Fission Products ~ (142) La

With the development of science and technique, the accuracy of nuclear decay data become more and more important. Precise measurement could be done only after the interested nuclides being separated from reaction products. In this work, a rapid separation system based on SISAK technique was established to isolate ¹⁴²La successfully from fission products.SISAK is an on-line chemical separation technique based on multi-stage liquid-liquid extraction separation using high-speed centrifuges for phase separation. SISAK means Short-lived Isotopes Studied by the AKUFVE technique (AKUFVE is a Swedish acronym for Apparatus for continuous investigation of distribution coefficients in solvent extraction).Here in this paper, development, principle, procedure and application of SISAK have been described in detail. The equipment based on SISAK technique was established in China Institute of Atomic Energy (CIAE), which consists of gas-jet recoil transportation unit, chemical separation unit, product collection & detection unit and accessory unit. With this equipment and developed rapid separation procedure, ¹⁴²La was separated successfully from complicated fission products. Short-lived nuclides recoiled out of an irradiated multi-stage Uranium target were delivered into transport system by a gas or aerosols in the carrier gas. They were separated by high-speed extraction centrifuge after being degassed and then the interested nuclide can be detected by detection system.SISAK technique is often applied in the separation for nuclides with seconds or minutes of half-life. However, we used it to separate ¹⁴²La which half-life is in hour-level. According to the separation procedure designed in the paper, the activity of ¹⁴²La acquired is more than 10⁴ Bq and the decontamination factors for mostγ-emitters are higher than 10³.The result demonstrated that SISAK technique is very useful for separating short-lived nuclides. Furthermore, combined with mass separator or on-line scintillation detector, SISAK could be used for the separation and identification of short-lived nuclides, the synthesis of super-heavy elements and the study of nuclides far from stability. So the study of SISAK has great significance in chemical research.