Atomic nuclei are known to exist in a variety of shapes which include spherical, prolate (like a football), oblate (like a doorknob), and octupole (like a pear). Although these are different shapes, they all have one common factor: they are all symmetric about at least one axis. Somewhat surprisingly, the most difficult nuclear shape to identify is one in which there is no symmetry axis, which would look like a kiwi fruit. A nucleus with this asymmetric shape is often said to possess ``triaxial deformation'' or have ``triaxiality.'' In fact, only a few nuclei have established cases of triaxial deformation. However, this shape only occurs in these nuclei when it is in a highly excited state. Here, the nucleus is significantly more elongated or more deformed than when in a less excited state. This phenomenon is known as ``superdeformation,'' and therefore when the nucleus is also triaxial it is said to have triaxial superdeformation. It was once thought triaxial superdeformation would only occur in nuclei with neutron numbers near N = 94, but recently we discovered possible triaxial deformation in an isotope of hafnium having N = 102. In order to confirm this shape, we must perform another experiment with higher statistics than the first, to search for the presence of wobbling excitations. These are the quantum equivalent to an asymmetric top being spun which would display a wobbling motion. We will also begin a search for evidence of triaxial superdeformation in the neighboring tantalum nuclei with neutron numbers near N = 100. Therefore, it is our intent to firmly establish this region of nuclei as having stable triaxial deformation.
We will also participate and possibly lead experiments utilizing neutron-rich radioactive beams at Oak Ridge National Laboratory. Until recently, these species of isotopes could not be studied easily as few methods existed for exciting the neutron-rich nuclei. However, Oak Ridge can now produce beams of these rare isotopes for further analysis. Participation in these experiments will better prepare the principal investigator to propose future experiments at this facility and eventually at the Rare Isotope Accelerator. In addition, a make-shift radioactive beam can be used at the Florida State University laboratory to study select neutron-rich nuclei.
Undergraduate involvement will be vital in all of these projects. Students will learn basic nuclear physics techniques at the Naval Academy, and then apply this knowledge at the laboratories where this work will be completed. The opportunity to use world-class facilities will hopefully propel these students into scientific careers.
