Fission cross section measurements for 240Pu, 242Pu

This report comprises the deliverable 1.5 of the ANDES project (EURATOM contract FP7-249671) of Task 3 "High accuracy measurements for fission" of Work Package 1 entitled "Measurements for advanced reactor systems". This deliverables provide evidence of a successful completion of the objectives of Task 3.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the 233U(n, γ) cross-section at the n_TOF facility at CERN, where it was coupled to the n_TOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed.Peer reviewe

Quasi-unidirectional flax composite reinforcement: Deformability and complex shape forming

Deformability and complex shape forming of a quasi-unidirectional flax reinforcement for composite materials (commercialized as FLAXPLY UD 180 by LINEO) are experimentally investigated. The first part of the study is focused on the understanding and measurement of the main deformation modes: in-plane tension, in-plane shear, and out-of-plane bending and compression, which are involved during draping of composite reinforcements. The second part is dedicated to the experimental study of a complex 3D shape forming, namely double-dome. The obtained results represent a complete data set for the characterisation of the deformation capabilities of the quasi-unidirectional flax reinforcement during complex 3D shape forming processes and provide benchmarking data for numerical predictions

DEFORMABILITY OF A FLAX REINFORCEMENT FOR COMPOSITE MATERIALS

In this work, the deformability of a flax fabric adopted as composite reinforcement is experimentally investigated. The fabric (commercialized as FLAXPLY UD 180 by LINEO) is a quasi-unidirectional woven fabric with thin weft yarns connecting thick slightly twisted warp using satin weave interlacing pattern. The study is dedicated to the understanding and measurement of the main deformation mechanisms occurring during forming processes. The deformation during extension is investigated under uniaxial and biaxial loading in the in-plane tow directions (i.e. warp and weft). Particular attention is dedicated to the behavior during shear loading because this is considered the primary deformation mechanism in the reinforcement forming. Uniaxial bias extension and picture frame tests are adopted to measure the shear deformation. The tests are assisted by digital image correlation (DIC) technique to have a continuous measurement of the local deformation in the fabric plane during loading

Forming of a flax reinforcement for composite materials

This research work is focussed on the experimental complex shape forming of a flax fabric adopted as composite reinforcement. The fabric is a quasi-unidirectional woven fabric with thin twisted weft yarns connecting thick warp yarns using a warp rep weave interlacing pattern. The first part of the study is dedicated to the experimental measurement of the main deformation mechanisms of the fabric involved in forming processes: in-plane uniaxial and biaxial tension; in-plane shear; out-of-plane bending and out-of-plane compression. The second part is devoted to the experimental study of a complex 3D shape forming. The formability of the quasi-unidirectional flax reinforcement was observed using a double-dome punch in an open die forming process

Prompt-fission γ-ray spectral characteristics from 239Pu(nth,f)

In this paper we present new results for prompt fission γ -ray spectral characteristics from the thermal neutron induced fission of 240 Pu ∗ . The measured spectra were unfolded by using the detectors' response functions, simulated with geant4. We obtained in average per fission a γ -ray multiplicity ¯¯¯¯ M γ = ( 7.35 ± 0.12 ) , a mean photon energy ¯ ε γ = ( 0.85 ± 0.02 ) MeV, and an average total energy released in fission ¯¯¯ E γ , tot = ( 6.27 ± 0.11 ) MeV. Our results are in good agreement with historical data measured in the 1970s by Verbinski et al. and results from recent calculations in the framework of Monte Carlo Hauser–Feshbach models. Our measured average total energy is slightly smaller than the one deduced previously and present in evaluated data. From this we conclude that the 239 Pu ( n th , f ) reaction may be ruled out as possible source of γ heating underestimation, when compared with benchmark calculations based on existing nuclear data

Prompt-fission γ-ray spectral characteristics from Pu-239(nth,f)

In this paper we present new results for prompt fission γ-ray spectral characteristics from the thermal neutron induced fission of 239Pu. The measured spectra were unfolded using the detectors’ response functions simulated with Geant4. We obtained in average per fission a γ-ray multiplicity M ̄γ = (7.13 ± 0.12), a mean photon energy ε ̄γ = (0.85 ± 0.02) MeV, and an average total energy released in fission Eγ,tot = (6.10 ± 0.11) MeV. Our results are in good agreement with historical data measured in the 1970’s by Verbinski et al. and results from calcualtions in the framework of Monte-Carlo Hauser Feshbach models. Our measured average total energy is slightly smaller than the one deduced previously and present in evaluated data. From this we conclude that the 239Pu(nth, f) reaction may be ruled out as possible source of γ heating under-estimation, when compared to benchmark calculations based on existing nuclear data.JRC.G.2-Standards for Nuclear Safety, Security and Safeguard