Measurement of the U-235(n, f) cross section relative to the Li-6(n, t) and B-10(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOF
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10405001" target="_blank" >RIV/00216208:11320/19:10405001 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=zlknzUw10c" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=zlknzUw10c</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1140/epja/i2019-12802-7" target="_blank" >10.1140/epja/i2019-12802-7</a>
Alternative languages
Result language
angličtina
Original language name
Measurement of the U-235(n, f) cross section relative to the Li-6(n, t) and B-10(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOF
Original language description
.The U-235(n, f ) cross section was measured at n_TOF relative to Li-6(n, t) and B-10(n,alpha) , with high resolution ( L=183.49(2) m) and in a wide energy range (25meV-170keV) with 1.5% systematic uncertainty, making use of a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the yields of the U-235(n, f ) and of the two reference reactions under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10-30keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the cross section in the 9-18keV neutron energy range is indeed overestimated by almost 5% in the recently released evaluated data files ENDF/B-VIII.0 and JEFF3.3, as a consequence of a 7% overestimate in a single GMA node in the IAEA reference file. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The results here reported may lead to a reduction of the uncertainty in the 1-100keV neutron energy region. Finally, from the present data, a value of 249.7 +/- 1.4( stat )+/- 0.94( syst ) beV has been extracted for the cross section integral between 7.8 and 11eV, confirming the value of 247.5 +/- 3 beV recently established as a standard.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10304 - Nuclear physics
Result continuities
Project
<a href="/en/project/LTT17018" target="_blank" >LTT17018: Getting new knowledge of the microworld using the CERN infrastructure</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
European Physical Journal A
ISSN
1434-6001
e-ISSN
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Volume of the periodical
55
Issue of the periodical within the volume
7
Country of publishing house
DE - GERMANY
Number of pages
19
Pages from-to
120
UT code for WoS article
000477050900001
EID of the result in the Scopus database
2-s2.0-85069686674