Triaxial Superdeformation in Nuclei Near N=100

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Atomic nuclei are known to exist in a variety of shapes whichinclude spherical, prolate (like a football), oblate (like a doorknob), and octupole (like a pear). Although these are different shapes, theyall have one common factor: they are all symmetric about at least one axis. Somewhat surprisingly, the most difficult nuclear shape to identify is one inwhich there is no symmetry axis, which would look like a kiwi fruit. Anucleus with this asymmetric shape is often said to possess ``triaxialdeformation'' or have ``triaxiality.'' In fact, only a few nuclei haveestablished cases of triaxial deformation. However, this shape only occurs in thesenuclei when it is in a highly excited state. Here, the nucleus issignificantly more elongated or more deformed than when in a less excited state. This phenomenon is known as ``superdeformation,'' and therefore when thenucleus is also triaxial it is said to have triaxial superdeformation. Itwas once thought triaxial superdeformation would only occur in nuclei withneutron numbers near N = 94, but recently we discovered possible triaxialdeformation in an isotope of hafnium having N = 102. In order to confirm thisshape, we must perform another experiment with higher statistics than thefirst, to search for the presence of wobbling excitations. These are thequantum equivalent to an asymmetric top being spun which would display awobbling motion. We will also begin a search for evidence of triaxial superdeformation in the neighboring tantalum nuclei with neutronnumbers near N = 100. Therefore, it is our intent to firmly establish thisregion of nuclei as having stable triaxial deformation.We will also participate and possibly lead experiments utilizingneutron-rich radioactive beams at Oak Ridge National Laboratory. Until recently,these species of isotopes could not be studied easily as few methodsexisted for exciting the neutron-rich nuclei. However, Oak Ridge can nowproduce beams of these rare isotopes for further analysis. Participation inthese experiments will better prepare the principal investigator topropose future experiments at this facility and eventually at the Rare IsotopeAccelerator. In addition, a make-shift radioactive beam can be used at theFlorida 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 becompleted. The opportunity to use world-class facilities will hopefully propelthese students into scientific careers.