The isomeric ratio in thermal and fast neutron capture of americium-241

Journal Article · Thu Jul 01 04:00:00 EDT 1982 · Nucl. Sci. Eng.; (United States)

DOI:https://doi.org/10.13182/NSE82-6· OSTI ID:6080929

Wisshak, K; Kappeler, F; Wickenhauser, J

A new experimental method has been used to determine the isomeric ratio (IR) in neutron capture of /sup 241/Am in a differential experiment. Thin /sup 241/Am samples have been activated with subthermal monoenergetic neutrons of 14.75 meV and quasi-monoenergetic neutrons of about 30 keV. The decay of the /SUP 242g/ Am nuclei produced has been determined by observing the emitted beta spectrum in a mini-orange spectrometer. The measurements have been performed relative to gold. The ratio R/sub 1/ = sigma..gamma.. (/sup 241/Am ..-->.. /SUP 242g/ Am)exclamationsigma..gamma..(Au) was found to be R/sub 1/ = 5.79 + or - 0.33 at 14.75 meV and R/sub 1/ = 2.73 + or - 0.16 at about 30 keV. The corresponding IRs, sigma..gamma..(/sup 241/Am..-->.. /SUP 242g/ Am)/sigma..gamma..(Am), are 0.92 + or - 0.06 at 14.75 meV and 0.65 + or 0.05 at about30 keV. Detailed theoretical calculations of the total capture cross section, the IR, and the capture gamma-ray spectra were performed in the energy range from 1 to 1000 keV taking advantage of recently available information on the discrete level scheme of /sup 242/Am. With the present knowledge on the level scheme of /sup 242/Am, it seems to be difficult to reproduce the strong energy dependence of IR as indicated by the experimental results.

• Research Organization: Kernforschungszentrum Karlsruhe, GmbH, Institut fur Angewandte Kernphysik Postfach 3640, C-7500 Karlsruhe, Germany, F.R.
• OSTI ID: 6080929
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 81:3; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

652025* -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMERICIUM 241 TARGET
BARYON REACTIONS
BARYONS
BETA SPECTROSCOPY
CALCULATION METHODS
CAPTURE
CROSS SECTIONS
DATA
DECAY
ELEMENTARY PARTICLES
ELEMENTS
ENERGY DEPENDENCE
EXPERIMENTAL DATA
FAST NEUTRONS
FERMIONS
GAMMA SPECTRA
GOLD
HADRON REACTIONS
HADRONS
INFORMATION
INFRARED SPECTRA
ISOMERIC NUCLEI
MEASURING INSTRUMENTS
METALS
NEUTRON REACTIONS
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
NUMERICAL DATA
SAMPLING
SPECTRA
SPECTROMETERS
SPECTROSCOPY
TARGETS
THEORETICAL DATA
THERMAL NEUTRONS
TRANSITION ELEMENTS