Measurement of the neutron capture cross section of {sup 234}U in n-TOF at CERN

Conference · Sat Jul 01 00:00:00 EDT 2006

OSTI ID:22040591

Dridi, W; Aerts, G; Andriamonje, S; Berthoumieux, E; Gunsing, F; Pancin, J; Perrot, L; Plukis, A ^[1]; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C ^[2]; Alvarez, H; Duran, I; Paradela, C ^[3]; Alvarez-Velarde, F; Cano-Ott, D; Embid-Segura, M; Gonzalez-Romero, E; Guerrero, C ; Villamarin, D; Vincente, M C ^[4]; Andrzejewski, J; Marganiec, J ^[5]; Assimakopoulos, P; Karadimos, D; Karamanis, D; Papachristodoulou, C; Patronis, N ^[6]; others, and

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1. CEA/Saclay, DSM/DAPNIA, Gif-sur-Yvette (France)
2. Istituto Nazionale di Fisica Nucleare, Trieste (Italy)
3. Universidade de Santiago de Compostela (Spain)
4. Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain)
5. Univ. of Lodz, Lodz (Poland)
6. Univ. of Ioannina (Greece)

Accurate and reliable neutron capture cross sections are needed in many research areas, including stellar nucleosynthesis, advanced nuclear fuel cycles, waste transmutation, and other applied programs. In particular, the accurate knowledge of {sup 234}U(n, {gamma}) reaction cross section is required for the design and realization of nuclear power stations based on the thorium fuel cycle. We have measured the neutron capture cross section of {sup 234}U at the recently constructed neutron time-of-flight facility n-TOF at CERN [2] in the energy range from 0.03 eV to 1 MeV with high accuracy due to a combination of features unique in the world: A high instantaneous neutron fluence and excellent energy resolution of the n-TOF facility, an innovative Data Acquisition System based on flash ADCs [3] and the use of a high performance 4{Pi} BaF{sub 2} Total Absorption Calorimeter (TAC) as a detection device [4, 5], In this paper, we will describe the experimental apparatus including the various TAC components and its performance. We also will present results from the {sup 234}U(n, {gamma}) measurement. A sample of 38.7 mg of {sup 234}U{sub 3}O{sub 8} was pressed into a pellet and doubly encapsulated between Al and Ti foils which were 0.15 mm and 0.2 mm thick, respectively. Monte-Carlo simulations with GEANT4 [6] of the detector response have been performed. After the background subtraction and correction with dead time and pile-up, the capture yield from 0.03 eV up to 1.5 keV was derived. Preliminary analysis of the capture yield in terms of R-matrix resonance parameters is discussed. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22040591
• Resource Relation: Conference: PHYSOR-2006: American Nuclear Society's Topical Meeting on Reactor Physics - Advances in Nuclear Analysis and Simulation, Vancouver, BC (Canada), 10-14 Sep 2006; Other Information: Country of input: France; 20 refs.
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCURACY
ANALOG-TO-DIGITAL CONVERTERS
BARIUM FLUORIDES
CALORIMETRIC DOSEMETERS
CERN
COMPUTERIZED SIMULATION
CROSS SECTIONS
DATA ACQUISITION SYSTEMS
DEAD TIME
ENERGY RANGE
ENERGY RESOLUTION
FOUR-PI DETECTORS
MONTE CARLO METHOD
NEUTRON FLUENCE
NEUTRON REACTIONS
R MATRIX
TIME-OF-FLIGHT METHOD
URANIUM 234
URANIUM OXIDES U3O8