62,861 research outputs found
Pathways towards the nuclear revival in Finland, France, and the UK
Nuclear power is undergoing a revival in a number of countries of both developed and developing world, and is increasingly presented as a solution to the problems of climate change and energy security. This paper analyses the history of and the debates on nuclear power in France, the UK and Finland, all of which are in the process of either planning or building new nuclear plants. The paper traces the history of nuclear power since the early post-War years, distinguishing five distinct phases of development, from the early period of nuclear enthusiasm, through the emergence of doubt and risk in the 70s and 80s, to the recent 'nuclear renaissance'. Emphasis in the analysis is placed on issue framings, argumentative strategies, the role of independent expertise, public opinion and the degree of openness of decision-making. Key similarities, converging trends and differences between the countries are identified and tentative conclusions drawn on the potential stability of the current framing of nuclear energy as a response to the double challenge of climate change and energy security
Futur du nucléaire - Nucléaire du futur
Ecole de Physique Les Houches SFP- SFEN-PACE-CEA-IN2P3 Région RhÎne-AlpesL'énergie nucléaire peut jouer un rÎle important dans un futur proche pour la production massive d'énergie au niveau mondial. Pour cela, elle devra satisfaire un certain nombre de critÚres généraux qui ont été définis par les organismes internationaux (IAEA, le Forum International Génération IV), et qui sont : une sûreté accrue, la durabilité par l'utilisation des noyaux fertiles, une bonne gestion des déchets, un champ élargi d'utilisations, une rentabilité économique acceptable et la résistance à la prolifération. Plusieurs concepts sont à l'étude voire en développement pour essayer de répondre à ces critÚres au sein de collaborations internationales plus ou moins larges. AprÚs une présentation du contexte énergétique et de son futur au niveau mondial, ce papier exposera les arguments en faveur d'un futur du nucléaire en détaillant les avantages de cette forme de production d'énergie, avant une présentation des principaux systÚmes en cours d'étude pour le nucléaire du futur
Muon tomography applied to active volcanoes
Muon tomography is a generic imaging method using the differential absorption
of cosmic muons by matter. The measured contrast in the muons flux reflects the
matter density contrast as it does in conventional medical imaging. The
applications to volcanology present may advantadges induced by the features of
the target itself: limited access to dangerous zones, impossible use of
standard boreholes information, harsh environmental conditions etc. The
Diaphane project is one of the largest and leading collaboration in the field
and the present article summarizes recent results collected on the Lesser
Antilles, with a special emphasis on the Soufri\`ere of Guadeloupe.Comment: 7 pages, 7 figures, International Conference on New
Photo-detectors,PhotoDet2015, 6-9 July 2015, Moscow, Troitsk, Russia.
Submitted to Po
Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems
We report experimental signals of Bose-Einstein condensation in the decay of
hot Ca projectile-like sources produced in mid-peripheral collisions at
sub-Fermi energies. The experimental setup, constituted by the coupling of the
INDRA 4 detector array to the forward angle VAMOS magnetic spectrometer,
allowed us to reconstruct the mass, charge and excitation energy of the
decaying hot projectile-like sources. Furthermore, by means of quantum
fluctuation analysis techniques, temperatures and mean volumes per particle "as
seen by" bosons and fermions separately are correlated to the excitation energy
of the reconstructed system. The obtained results are consistent with the
production of dilute mixed (bosons/fermions) systems, where bosons experience a
smaller volume as compared to the surrounding fermionic gas. Our findings
recall similar phenomena observed in the study of boson condensates in atomic
traps.Comment: Submitted to Phys. Rev. Lett. (december 2014
Measurement of the Multi-TeV Neutrino Interaction Cross-Section with IceCube Using Earth Absorption
Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrinoânucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4âTeV) that are available at neutrino beams from accelerators1,2. Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrinoânucleon interaction cross-section for neutrino energies 6.3â980âTeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model3, consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions4 or the production of leptoquarks5. This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks
Structure properties of even-even actinides
Structure properties of fifty five even-even actinides have been calculated
using the Gogny D1S force and the Hartree-Fock-Bogoliubov approach as well as
the configuration mixing method. Theoretical results are compared with
experimental data.Comment: 5 pages, 5 figures, proceeding of FUSION0
Gamma ray production cross sections in proton induced reactions on natural Mg, Si and Fe targets over the proton energy range 30 up to 66 MeV
Gamma-ray excitation functions have been measured for 30, 42, 54 and 66 MeV
proton beams accelerated onto C + O (Mylar), Mg, Si, and Fe targets of
astrophysical interest at the separate-sector cyclotron of iThemba LABS in
Somerset West (Cape Town, South Africa). A large solid angle, high energy
resolution detection system of the Eurogam type was used to record Gamma-ray
energy spectra. Derived preliminary results of Gamma-ray line production cross
sections for the Mg, Si and Fe target nuclei are reported and discussed. The
current cross section data for known, intense Gamma-ray lines from these nuclei
consistently extend to higher proton energies previous experimental data
measured up to Ep ~ 25 MeV at the Orsay and Washington tandem accelerators.
Data for new Gamma-ray lines observed for the first time in this work are also
reported.Comment: 11 pages, 6 figures. IOP Institute of Physics Conference Nuclear
Physics in Astrophysics VII, 28th EPF Nuclear Physics Divisional Conference,
May 18-22 2015, York, U
Towards a unitary Dalitz plot analysis of three-body hadronic B decays
A unitary model of the final state kaon pion interaction amplitudes in the B
--> K pi pi decays is constructed. The weak decay penguin amplitudes, derived
in QCD factorization, are supplemented by phenomenological contributions. The
strange kaon- pion scalar and vector form factors are used to calculate the
kaon pion effective mass and helicity angle distributions, branching ratios, CP
asymmetries and the phase difference between the B0 and anti B0 decay
amplitudes to K*(892) pi. The fit on the phenomenological parameters leads to a
good agreement with the experimental data, particularly for the
B --> K*(892) pi decays. However, our predicted B+- --> K*0(1430) pi+-,
K*0(1430)--> K+-pi-+ branching fraction is smaller than the results of the
Belle and BaBar collaborations, obtained from isobar model analyses. A new
parameterization of the S-wave kaon- pion effective mass distribution, which
can be used in future experimental Dalitz plot analyses, is proposed.Comment: 5 pages, 1 figure, contribution to Proc. Int. Europhysics Conference
on High Energy Physics (HEP2009), July 16-22, 2009, Krakow, Poland,
PoS(HEP2009)20
The Air Microwave Yield (AMY) experiment - A laboratory measurement of the microwave emission from extensive air showers
The AMY experiment aims to measure the microwave bremsstrahlung radiation
(MBR) emitted by air-showers secondary electrons accelerating in collisions
with neutral molecules of the atmosphere. The measurements are performed using
a beam of 510 MeV electrons at the Beam Test Facility (BTF) of Frascati INFN
National Laboratories. The goal of the AMY experiment is to measure in
laboratory conditions the yield and the spectrum of the GHz emission in the
frequency range between 1 and 20 GHz. The final purpose is to characterise the
process to be used in a next generation detectors of ultra-high energy cosmic
rays. A description of the experimental setup and the first results are
presented.Comment: 3 pages -- EPS-HEP'13 European Physical Society Conference on High
Energy Physics (July, 18-24, 2013) at Stockholm, Swede
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