Multi-detector registration system for the study of multi-body decay of heavy body nuclei

[摘要] Nuclearssion is commonly known as a process where a heavy nucleus such as Uraniumor Thorium decays into two fragments of roughly equal mass. On occasion however, insteadof decay into two parts a process known as binaryssion, the nucleus can decayinto three fragments. In this decay channel known as ternaryssion, the nucleus splitsinto three fragments with the third particle being too light compared to the mainssionfragments. There are also instances where heavy nuclei split into three fragments of comparablemasses, the so called \true ternaryssion as was predicted by the theoreticalcalculations of Strutinsky [Str63]. While theoretical predictions hold promises for this decaymode, experimental attempts had little success in proving the existence of true ternary ssion in low energyssion. The challenges and di culties faced by experimentalist incon rming the existence of true ternaryssion also proved that thisssion mode is a veryrare phenomenon.This thesis is devoted to the investigation of ternaryssion know as collinear cluster tripartition(CCT) in spontaneousssion of 252Cf, and the design and development of twotime-of-ight spectrometers aimed at identifying all collinear multi-body decay partnersdirectly. Prior to this study the only technique that was used at identifying decay partnersin CCT was the \missing mass approach. In this approach only two partners are identi eddirectly with the third partner being identi ed by subtracting the two observed partnersfrom the initial mass of the nucleus.The experimental results from the two spectrometer setups showed that it was possibleto identify all three partners of the CCT channel. The results also con rmed the existenceof the so called \Sn lost CCT mode which was already observed in earlier experiments.

[发布机构] Stellenbosch University