UT-ORNL Study: No Double Magic for Calcium-52


The image above shows the chain of the studied calcium isotopes. The “doubly magic” isotopes with mass numbers 40 (Ca-40) and 48 (Ca-48) exhibit equal charge radii. The first measurement of the charge radius in Ca-52 yielded an unexpectedly large result. Image: COLLAPS Collaboration/Ronald Fernando Garcia Ruiz.

Nuclear theorists from UT and Oak Ridge National Laboratory are among the researchers who have found that Calcium-52 doesn’t quite have the magic scientists once thought. The results were published this week in Nature Physics.

Calcium, at number 20 on the periodic table, has 20 protons, which places it squarely in the “magic” numbers of nuclear physics. Scientists have found that if an atomic nucleus has either protons or neutrons in certain numbers—2, 8, 20, 28, 50, 82, or 126—they arrange themselves in complete shells and make the nucleus more strongly bound than their neighbors. A doubly-magic nucleus has both protons and neutrons in magic numbers.

UT scientists who participated in the project include Andreas Ekström, a postdoctoral student; Gaute Hagen, physics adjunct faculty and ORNL Physics Division staff; Gustav Jansen, a UT postdoctoral student at the time of the study who now is ORNL Staff at the Oak Ridge Leadership Computing Facility; Thomas Papenbrock, professor of physics; and Kyle Wendt, a postdoctoral student at the time of the study who now is a postdoctoral student at Darmstadt Technical University.

Continue reading on the Department of Physics and Astronomy’s website.