The study of samarium-150 through the beta decay of promethium-150 and europium-150 .

摘要

The N = 88 isotones lie on the onset of nuclear deformation and have a complicated nuclear structure. To better understand this region, the nuclear levels of 150Sm were studied in three different β decay experiments. De-populating γ-rays were measured using the 8π spectrometer, an array of 20 Compton suppressed Ge detectors. Levels of 150Sm were populated in varying degrees by three radioactive sources: 150Pm (J = 1−, Q = 3454 keV), 150mEu (J = 0−, Q = 2303 keV), and 150gEu (J = 5−, Q = 2261 keV), which were all produced at the 88″ cyclotron located at LBNL. Among several changes to the existing level structure were the addition of a 0 + level identified at 1603.24 keV, as well as confirming another questioned 0+ assignment of the 1786.47 keV level. Angular correlation analysis was carried out on many different transitions, allowing for spin assignments and the determination of mixing ratios. The results from these three experiments provide extensive new data, and give a fairly complete picture of nuclear levels below about 2 MeV and J ≤ 6. The theoretical interpretation of this particular nucleus is still open to question. The data from these experiments, used in conjunction with other studies of nuclei in this same mass region (which are currently underway), may provide further insight into this transition region.