Speaker
Description
The level structures of two tungsten isotopes, $^{165}$W and $^{169}$W, have been experimentally well known up to high spin since over 30 years ago. However, in both cases, these structures were not connected to the ground states of the two nuclei. The reason for this, as it turns out, is the presence of an isomeric state preventing the observation of all transitions down to the ground state. These nuclei have now been studied using fusion-evaporation reactions at the Accelerator Laboratory of the University of Jyväskylä (JYFL). The connections between the floating levels and their respective ground states have been probed using the recoil-decay tagging method. The experimental setup at JYFL included the recoil-separator MARA, JUROGAM 3 Ge-detector array, and several detectors at the focal plane.The observed isomeric states have been assigned spin-parities of $(13/2^+)$ in $^{165}$W and $(9/2^+)$ in $^{169}$W and half-lives of $7.4(2)$ µs and $7.4(5)$ µs, respectively, have been measured. In this presentation, I will describe the setups in detail and how these results were extracted from unexpected sources of data - produced on the side in a calibration measurement of an experiment and during a competition for high-school students.