People - Written by on July 23, 2013

OLCF User Earns Early Honor

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Hagen recognized by DOE for computational physics work

Oak Ridge National Laboratory's Gaute Hagen.

Oak Ridge National Laboratory’s Gaute Hagen.

OLCF user Gaute Hagen, a researcher in ORNL’s Physics Division, recently received an Early Career Award from the Department of Energy’s Office of Science.

Hagen’s award-winning project, entitled “State of the Art Microscopic Computations of Weak Processes in Nuclei,” aims to develop novel extensions of computational methods that address fundamental questions in physics such as “What is the nature of the neutrino?” and “What are the mechanisms for the production of elements heavier than iron?”

By using computation to study weak nuclear decays, Hagen’s research will enable predictions of properties of medium-mass, neutron-rich nuclei at a microscopic level. These advanced calculations will shed new light on the mechanisms behind weak decays and will be relevant for future experiments at laboratories worldwide.

“It is truly an honor to be a recipient of the DOE Early Career award. The continued support of my colleagues and the unique opportunities at ORNL have been key to winning this award,” said Hagen. “This research project makes it possible for me to pursue some of the long standing problems in the physics of weak processes in nuclei.”

Hagen has a proven track record of success on OLCF systems. He was recently part of an international team that used microscopic coupled-cluster theory to compute properties of very neutron rich calcium isotopes. Some of their findings challenge the standard nuclear shell model, which has been tremendously successful in explaining the properties of nuclei near the valley of beta stability. Isotopes such as calcium-40 (20 protons, 20 neutrons) and calcium-48 (20 protons, 28 neutrons) are doubly magic, i.e. they are exceptionally stable because neutrons and protons completely fill a shell completely.

Whether calcium-54 is magic has been an open question until now. In their recent work, Hagen and his fellow team members found that calcium-54 is not magic and that very neutron-rich calcium isotopes (with a neutron-to-proton ratio close to two) do not follow the rules of the shell-model. Due to an intricate interplay between the very weakly bound outermost neutrons and three-nucleon forces, the traditional shell structure melts away and rearranges itself in a new and unexpected way. Hagen and collaborators made predictions that defy textbook paradigms, and in particular their prediction of calcium-54 was recently verified experimentally at the RIKEN natural sciences institute in Japan. The researchers used nearly 200,000 processor hours on Jaguar to carry out the calculations. Their findings were reported in the May 2012 issue of Physical Review Letters.

The award program, now in its fourth year, is designed to bolster the nation’s scientific workforce by providing support to exceptional researchers during crucial early career years when many scientists do their most formative work. This year’s 61 awardees were selected from a pool of 770 university- and national laboratory-based applicants.

“This highly competitive program is a well-deserved recognition for early-career scientists who are launching their own research programs,” ORNL Director Thom Mason said. “We are delighted that four of this year’s awards are going to researchers associated with ORNL.”

Hagen’s OLCF-related work includes:

 Oxygen-23 Loses Its Halo

Nuclear Theorist use Jaguar to Pin Down the Proton-Halo State in Fluorine-17