Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np

Conference · Fri Feb 19 00:00:00 EST 1988

OSTI ID:5291231

Hoff, R W

Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age must be considered more uncertain than if the calculated rates of beta-delayed fission were found to be acceptable. The nuclear level structure of 238Np has been investigated using the 237Np(n,..gamma..)238Np reaction and the alpha decay of 242mAm as experimental probes. Having established a level scheme for 238Np that includes 47 excited levels and 93 secondary transitions, we find a high degree of correspondence between the experimental band structure and that of a semi-empirical model developed to predict excitations in odd-odd deformed nuclei. 35 refs., 4 figs., 3 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5291231
• Report Number(s): UCRL-97056; CONF-8708101-15; ON: DE88006577
• Resource Relation: Conference: 6. international symposium on capture gamma-ray spectroscopy, Leuven, Belgium, 31 Aug 1987; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
NEPTUNIUM 237 TARGET
NEUTRON REACTIONS
NEPTUNIUM 238
NUCLEAR STRUCTURE
ALPHA DECAY
CORRECTIONS
CROSS SECTIONS
DEFORMED NUCLEI
ENERGY LEVELS
EXPERIMENTAL DATA
FISSION
GAMMA SPECTROSCOPY
NUCLEAR PROPERTIES
NUCLEOSYNTHESIS
R PROCESS
ROTATIONAL STATES
URANIUM
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTINIDES
BARYON REACTIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DATA
DAYS LIVING RADIOISOTOPES
DECAY
ELEMENTS
EXCITED STATES
HADRON REACTIONS
HEAVY NUCLEI
INFORMATION
ISOTOPES
METALS
NEPTUNIUM ISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUMERICAL DATA
ODD-ODD NUCLEI
RADIOISOTOPES
SPECTROSCOPY
STAR EVOLUTION
SYNTHESIS
TARGETS
652020* - Nuclear Properties & Reactions
A=220 & above
Experimental
653001 - Nuclear Theory- Nuclear Structure
Moments
Spin
& Models