Cross section for inelastic neutron ''acceleration'' by {sup 178}Hf{sup m2}

Journal Article · Tue Feb 15 00:00:00 EST 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.83.024604· OSTI ID:21499421

Karamian, S A ^[1]; Carroll, J J ^[2]

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1. Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, 141980 (Russian Federation)
2. Department of Physics and Astronomy, Youngstown State University, Youngstown, Ohio, 44555 (United States)

The scattering of thermal neutrons from isomeric nuclei may include events in which the outgoing neutrons have increased kinetic energy. This process has been called inelastic neutron acceleration, or INNA, and occurs when the final nucleus, after emission of the neutron, is left in a state with lower energy than that of the isomer. The result, therefore, is an induced depletion of the isomer to the ground state. A cascade of several {gamma}'s must accompany the neutron emission to release the high angular momentum of the initial isomeric state. INNA was previously observed in a few cases, and the measured cross sections were only in modest agreement with theoretical estimates. The most recent measurement of an INNA cross section was {sigma}{sub INNA}=258{+-}58 b for neutron scattering by {sup 177}Lu{sup m}. In the present work, an INNA cross section of {sigma}{sub INNA}=168 {+-} 33 b was deduced from measurements of the total burnup of the high-spin, four-quasiparticle isomer {sup 178}Hf{sup m2} during irradiation by thermal neutrons. Statistical estimates for the probability of different reaction channels past neutron absorption were used in the analysis, and the deduced {sigma}{sub INNA} was compared to the theoretically predicted cross section.

• OSTI ID: 21499421
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 83, Issue 2; Other Information: DOI: 10.1103/PhysRevC.83.024604; (c) 2011 American Institute of Physics; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABSORPTION
ACCELERATION
CROSS SECTIONS
HAFNIUM 178
ISOMERIC NUCLEI
ISOMERS
KINETIC ENERGY
LUTETIUM 177
NEUTRON DIFFRACTION
NEUTRON EMISSION
PROBABILITY
SCATTERING
SPIN
THERMAL NEUTRONS
ANGULAR MOMENTUM
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COHERENT SCATTERING
DAYS LIVING RADIOISOTOPES
DIFFRACTION
ELEMENTARY PARTICLES
EMISSION
ENERGY
EVEN-EVEN NUCLEI
FERMIONS
HADRONS
HAFNIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LUTETIUM ISOTOPES
NEUTRONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
PARTICLE PROPERTIES
RADIOISOTOPES
RARE EARTH NUCLEI
SECONDS LIVING RADIOISOTOPES
SORPTION
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES