1,721,341 research outputs found
Neutron (n,xngamma) Cross-Section Measurements for 52Cr, 209Bi and 206,207,208Pb from Threshold up to 20MeV
No full textThe present report contains the thesis prepared by the author to obtain the degree of Doctor of Science from the University of Bucharest, Faculty of Physics. The work presented in this thesis was carried out at the GELINA facility and in the Neutron Physics Unit of the IRMM in Geel, Belgium. The work was performed while the author was employed as a JRC grant holder (contract number 20207) under the
supervision of A. Plompen. This work received financial support from the EUROTRANS Integrated Project under contract number 22390.JRC.D.5 - Neutron physic
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Neutron Data Measurements for Energy Applications and Nuclear Waste Transmutation at JRC-IRMM
No full textStudies in nuclear energy and transmutation of radioactive waste require neutron data for conceptual and performance studies, to determine the viability of advanced ideas such as an Accelerator Driven System and to fix the safety margins of any new concepts. IRMM's neutron data-measurement program addresses data needs associated with Accelerator Driven Systems, management of radioactive waste, the thorium fuel cycle, safety issues of conventional reactors. Ongoing and recently completed activities include capture and total cross-section measurements for 127,129I, 206Pb, and 232Th; precision total cross-section measurements for 240,242Pu; inelastic-scattering measurements for 52Cr, 58Ni, 209Bi, and 207Pb; (n,2n) measurements for 207Pb, and (n,xp); and (n,x alpha) and (n,xn) cross-section measurements with the activation technique. Capture, total, and inelastic cross-section measurements make use of the pulsed white neutron source Gelina, whereas activation cross sections are determined at the Van de Graaff laboratory. An overview will be given of the above-mentioned activities and an outlook will be provided for the measurements in the near future.JRC.D.5 - Neutron physic
Gamma Production Cross Sections for Inelastic Scattering and (n,2n) Reactions
No full textIn recent years it was shown that precise measurements of gamma-production cross
sections for gammas associated with inelastics scattering and (n,xn) reactions can be
performed at a white spectrum time-of-flight facility. This first of all leads to
continuous energy excitation curves characteristic of the decay of excited states in
the residual nuclei. With enriched samples the different reaction channels leading to
the same residual nucleus are disentangled. At GELINA modern data-acquisition
techniques have allowed access to the range from threshold to 20 MeV with excellent
incident energy resolution (1 keV at 1 MeV, 36 keV at 10 MeV). Since typically for
inelastic scattering excitation curves are measured of the decay of the first 15-20
excited levels, these experiments provide detailed information for the validation and
optimisation of nuclear model calculations. The relevant aspects are the optical
model, direct and pre-equilibrium reactions, level densities, the discrete level and
decay scheme and gamma-ray strength functions. Examples will be shown for 209Bi,
207Pb and 208Pb.JRC.D.5 - Neutron physic
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Cross-Section Measurements in the Fast Neutron Energy Range
No full textGeneration IV focuses research for advanced nuclear reactors on six concepts. Three of these concepts, the lead, gas and sodium fast reactors (LFR, GFR and SFR) have fast neutron spectra, whereas a fourth, the super-critical water reactor (SCWR), can be configured to have a fast spectrum. Such fast neutron spectra are essential to meet the sustainability objective of GenIV. Nuclear data requirements for GenIV concepts will therefore emphasize the energy region from about 1 keV to 10 MeV. Here, the potential is illustrated of the GELINA neutron time-of-flight facility and the Van de Graaff laboratory at IRMM to measure the relevant nuclear data in this energy range: the total, capture, fission and inelastic-scattering cross sections. In particular, measurement results will be shown for lead and bismuth inelastic scattering for which the need was recently expressed in a quantitative way by Aliberti et al. for Accelerator Driven Systems. Even without completion of the quantitative assessment of the data needs for GenIV concepts at ANL it is clear that this particular effort is of relevance to LFR system studies.JRC.D.5 - Neutron physic
IRMM projects related to IRDFF
No full textThe second Research Coordination Meeting (RCM-2) of the Coordinated Research Project (CRP F41031) "Testing and Improving the International Reactor Dosimetry and Fusion File (IRDFF)" was held 16 to 20 March 2015 in IAEA. At this meeting, the attendees presented their individual research contributions to CRP, summarised results and elaborated consolidated recommendations and actions for implementation for the period until RCM-3 which have to take place in the beginning of 2017. This Meeting also considered a perspective of the new Exercise on the verification of the neutron spectrum adjustment codes.JRC.D.4 - Standards for Nuclear Safety, Security and Safeguard
NEMEA-5 Neutron Measurements, Evaluations and Applications - Nuclear Data for Sustainable Nuclear Energy: Proceedings of the CANDIDE Workshop, 27-29 October 2008
Full text linkThe CANDIDE Workshop NEMEA-5, Neutron Measurements, Evaluations and Applications, Nuclear data for sustainable nuclear energy was held from 27 - 29 October 2008 in Ljubljana, Slovenia. These proceedings collect the full papers summarising the contributions to this workshop.JRC.DG.D.5 - Nuclear physic
The IRMM contribution to the CRP
No full textIn accordance with the recommendations of the International Nuclear Data Committee in May 2012, the Nuclear Data Section of IAEA has initiated a new Coordinated Research Project (CRP number F41031) with the main goal to test, validate and improve the international dosimetry library for fission and fusion (IRDFF). At the first Research Coordination Meeting in July 2013 in IAEA the attendees discussed the objectives of the whole CRP, presented their contributions and elaborated on consolidated recommendations and actions for implementation over the next 1.5 year period. This Summary Report documents the individual contributions and joint decisions made during this meeting.JRC.D.4 - Standards for Nuclear Safety, Security and Safeguard
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