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

To precisely measure the decay parameters of ¹⁴²La, the prepared ¹⁴²La sample must have high activity, high abundance and be free from carrier. A separation procedure 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. The established three-step chemical procedure involves one BaCl₂•2H₂O precipitation and two HDEHP extraction chromatographic separations. A specialized set of equipment was created and used to fast radiochemically separate the ¹⁴²La in batches. As a result, the total separation lasts about 20 min, and the chemical recovery rate is about 80%. The decontamination factors for other nuclides are greater than 10³, and the activity ratio of ¹⁴²La to ¹⁴¹La is more than 3.5.