Program - Brookhaven National Laboratory

atom is its mass. The mass of an atom is a fundamental quantity, and provides a wealth of data for related
fields, including basic and applied research. However, many of the relevant isotopes are short-lived and
need to be produced on-line. To overcome the obstacles given by the nature of rare isotopes, we have
developed very sensitive and fast methods using ion trap techniques at TITAN (TRIUMF’s Ion Trap of
Atomic and Nuclear science). Ion traps are typically used in analytical chemistry and atomic physics for
stable molecules or isotopes. We have adapted the technique to the challenging conditions and at TITAN
we are able to measure masses, using one single ion in as short as 8ms with 10ppb precision. This is
breaking a new world-record for precision mass spectroscopy. Using this appraoch we are able to probe a
wide range of isotopes, where masses are needed. Fields of interest include fundamental nuclear physics,
tests of symmetry concepts in the Universe, nuclear astrophysics, and metrology. In this talk I will report
on such measurements and show how and where they are applied in the various fields.
Session JC Nuclear Reaction Models
Wednesday March 6, 2013
Room: Empire East at 10:30 AM
JC 1 10:30 AM
A Modern Code System for Hauser-Feshbach Modeling Based on a Monte Carlo Framework
W.E. Ormand
Lawrence Livermore National Laboratory, Livermore, CA 9455
A new system of computer programs to perform Hauser-Feshbach modeling of nuclear reactions, specifically
those induced by neutrons, protons, deuterons, tritons, He, and alphas is presented. A principal feature
of the program is that the decay of the nuclear system is tracked via Monte Carlo methods. This easily
permits: 1) distinguishing between similar channels to the same product nucleus, such as (n,np) and
(n,pn) reactions, 2) explicit tracking of the spectra for all emitted particles in each channel, such as first
and second neutron, etc., 3) explicit treatment of the angular distributions for each emitted particle, and
3) analysis of correlations between the emitted particles. The code system is written in FORTRAN 95,
and makes use of derived types and dynamic memory allocation to both simplify the Hauser-Feshbach
bookkeeping and to minimize memory usage. The code system is driven with simple input commands,
and is designed with system defaults to permit a “push-button mode” for many reactions. Many physics
models are included and are modularized for flexibility, interchangeability, and user control over all input
parameters, including the resolution of the calculation. The framework of the code system will be described
and various applications will be demonstrated. This work was performed under the auspices of the U.S.
Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
JC 2 11:00 AM
The Impact of Intermediate Structure on the Average Fission Cross Section Calculations
O. Bouland
Physics Studies Laboratory, CEA, DEN, DER, SPRC, Cadarache, F-13108 Saint-paul-lez-Durance,
France
J.E. Lynn, P. Talou
Nuclear Physics Group, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545,
USA
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