Measurements of the subthreshold neutron induced fission cross-sections of {sup 234}U, {sup 237}Np and {sup 243}Am

Journal Article · Mon Oct 26 04:00:00 EST 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.56708· OSTI ID:21202230

Borzakov, S B; Florek, M; Konovalov, V Yu; Ruskov, I; Zamyatnin, S Yu; Zeinalov, S Sh ^[1]

---

1. Joint Institute for Nuclear Research, 141980 Dubna Moscow Region (Russian Federation)

The results of measurements of the fission cross-sections and resonance parameters {sigma}{sub 0}{gamma}{sub f} and {gamma}{sub f} of {sup 234}U and {sup 237}Np together with the preliminary results of {sup 243}Am fission cross-section measurements carried out in the framework of the program of studying subthreshold fission at the IBR-30 pulsed neutron source in Dubna are presented. The measurements were conducted by the time-of-flight technique. Fission events in {sup 234}U and {sup 237}Np were detected by two multisectional ionisation chambers containing {sup 234}U (about 100 mg) and {sup 237}Np (about 1.5 g) highly purified from isotopes with a large fission cross-section, such as {sup 235}U and {sup 239}Pu. Each chamber also contains a {sup 235}U target for neutron flux measurements. {sup 243}Am cross-section measurements are conducted with a back-to-back ionisation chamber containing about 2 mg of {sup 243}Am and 1 mg of {sup 235}U. The fission width is calculated in the region where the TOF resolution is sufficient to resolve most resonances at the energy up to 200 eV for {sup 234}U and below 50 eV for {sup 237}Np. The cross-sections in the energy region from 1 to 1000 eV are shown. The new upper limit for the thermal neutron induced fission of {sup 234}U is reported.

• OSTI ID: 21202230
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 447; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMERICIUM 243 TARGET
CROSS SECTIONS
FISSION
FISSION NEUTRONS
IONIZATION CHAMBERS
NEPTUNIUM 237 TARGET
NEUTRON FLUX
NEUTRON REACTIONS
RESOLUTION
RESONANCE
THERMAL NEUTRONS
TIME-OF-FLIGHT METHOD
URANIUM 234 TARGET
URANIUM 235 TARGET