三步分离法制备高丰度的^(142)La

Preparation of ^(142)La From Fission Product Using Three-step Separation

为精确测量142 La的衰变数据,需制备出高活度、高丰度、无载体的142 La样品。为去除或降低混合裂片中放射性镧的其他同位素,依据母子体衰变关系和同一质量链上独立产额的差异,提出了"三步分离"的分离模式。以一次BaCl2·2H2O沉淀、两次HDEHP萃取色层分离为手段建立了快速分离142 La的化学流程,并研制了批式快速化学分离装置。流程耗时约20min,化学回收率约80%,对其他核素的去污因数大于103,产品中142 La与141 La活度比大于3.5。

To precisely measure the decay parameters of 142^La ,the prepared 142 La sample must have high activity ,high abundance and be free from carrier .A separation proce-dure with three steps was proposed to prepare the sample from fission products .In order to receive optimal results ,the decay relationship of mother-daughter nuclides in the 142 mass chain and the differences of their independent fission yields need to be taken into account .T he established three-step chemical procedure involves one BaCl2 ·2H2 O precipitation and two HDEHP extraction chromatographic separations .A special-ized set of equipment was created and used to fast radiochemically separate the 142^La in batches .As a result ,the total separation lasts about 20 min ,and the chemical recovery rate is about 80% .T he decontamination factors for other nuclides are greater than 103 , and the activity ratio of 142^La to 141 La is more than 3.5 .