RUI: Using fIREBAll to Study Rare-Earth Nuclei

University Of Wisconsin-La Crosse, La Crosse WI

Investigators

Abstract

Nuclei are the basic building blocks of matter, and the understanding of their fundamental properties has been the goal of nuclear physics for decades. This award will support studies aimed at understanding the rotation and vibration of deformed nuclei using the La Crosse fIREBAll, a newly developed detector array at the University of Notre Dame to measure unique properties of rare-earth nuclei. Undergraduate students from the University of Wisconsin – La Crosse will be involved in every step of this project from experimental design to the broad dissemination of the results through published work and presentations at workshops and conferences. In addition, this project will inform the public through the podcast, My Nuclear Life which explores the intersection of nuclear science and society. Nuclei are the basic building blocks of matter and the understanding of their fundamental properties is the main goal of this award. Nuclei show some emergent collective behavior across isotopic and isobaric chains and are known to be deformed in shape in regions of the chart of nuclides away from closed shells. The existence of vibrational degrees of freedom superimposed on rotational states addresses a degree of freedom in nuclei and is one of the open questions in nuclear structure physics today. The intellectual merit of this project lies in investigating the vibrational degrees of freedom superimposed on the deformed ground states and the expected rotational excited states built upon them. The investigators aim to determine the characteristics of excited states by the measurement of conversion electrons in coincidence with gamma rays using the only array of its kind in the US. This project will use the newly commissioned La Crosse fIREBAll detector located at the University of Notre Dame's (ND) Nuclear Science Laboratory and multiple (alpha,2n) reactions to measure conversion electrons in rare-earth nuclei. From these experiments, extracted electron conversion coefficients will be used to calculated transition probabilities of interested levels. Analyses will be performed at the Institute for Structure & Nuclear Astrophysics at ND during the summer months and the University of Wisconsin - La Crosse (UWL) during the academic year. Additional research activities at UWL will include detector training for students, data analysis, and manuscript preparation. All experiments will be performed, analyzed, and disseminated in collaboration with UWL undergraduate students. As such, this work exemplifies the recommendation made in the 2023 Long Range Plan for Nuclear Science, to capitalize on the unique ways in which nuclear science can advance discovery by investing in a small-scale project at NSF-funded laboratory which increases the potential for discovery and will also train the next generation of nuclear scientists to meet societal needs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.