Measurement of the alpha ratio and (n, gamma) cross section of U-235 from 0.2 to 200 eV at n_TOF

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10421784" target="_blank" >RIV/00216208:11320/20:10421784 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Geo8NgnXWD" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Geo8NgnXWD</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevC.102.044615" target="_blank" >10.1103/PhysRevC.102.044615</a>

Result language

angličtina

Original language name

Measurement of the alpha ratio and (n, gamma) cross section of U-235 from 0.2 to 200 eV at n_TOF

Original language description

We measured the neutron capture-to-fission cross-section ratio (alpha ratio) and the capture cross section of U-235 between 0.2 and 200 eV at the n_TOF facility at CERN. The simultaneous measurement of neutron-induced capture and fission rates was performed by means of the n_TOF BaF2 Total Absorption Calorimeter (TAC), used for detection of gamma rays, in combination with a set of micromegas detectors used as fission tagging detectors. The energy dependence of the capture cross section was obtained with help of the Li-6(n, t) standard reaction determining the n_TOF neutron fluence; the well-known integral of the U-235(n, f) cross section between 7.8 and 11 eV was then used for its absolute normalization. The alpha ratio, obtained with slightly higher statistical fluctuations, was determined directly, without need for any reference cross section. To perform the analysis of this measurement we developed a new methodology to correct the experimentally observed effect that the probabilities of detecting a fission reaction in the TAC and the micromegas detectors are not independent. The results of this work have been used in a new evaluation of U-235 performed within the scope of the Collaborative International Evaluated Library Organisation (CIELO) Project, and are consistent with the ENDF/B-VIII.0 and JEFF-3.3 capture cross sections below 4 eV and above 100 eV. However, the measured capture cross section is on average 10% larger between 4 and 100 eV.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10304 - Nuclear physics

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

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review C

ISSN

2469-9985

e-ISSN

—

Volume of the periodical

102

Issue of the periodical within the volume

4

Country of publishing house

US - UNITED STATES

Number of pages

18

Pages from-to

044615

UT code for WoS article

000579839000003

EID of the result in the Scopus database

2-s2.0-85095131388