[en] A new experimental installation has been recently commissioned at the High Flux Reactor of Institut Laue-Langevin (ILL) in Grenoble (France). It gives access to high intensity neutron spectra from pure thermal (5.6x10¹⁴ n/s/cm²) to epithermal (2x10¹⁵ n/s/cm²). Several of low mass (10 μg) mono-isotopic targets of actinide elements are in the process of being irradiated and analyzed by a number of techniques, from nuclear spectroscopy to off-line mass spectrometry and innovative double-deposit fission micro-chambers. In the present paper we will present the first experiments carried out at the thermal neutron spectrum installation with ²⁴²Pu, ^241-243Am samples. (author)

[en] The gas turbine modular helium-cooled reactor (GT-MHR) is known probably as the best option for the maximum plutonium destruction in once-through cycle, even though the industrial fabrication of coated particle fuel still has to be proved. We perform detailed simulations along these lines by comparing different sets of data libraries in terms of k_eff eigenvalues, the length of the fuel cycle, neutronic characteristics and the evolution of fuel composition in particular. In all cases the same Monteburns code system is used making our results dependent only on the evaluated data tables. We show that in general the performance of GT-MHR is not considerably influenced by the choice of the data libraries employed. Nevertheless, a number of major differences among ENDF, JENDL and JEF data files are identified and quantified in terms of the averaged one-group cross sections both for military (MPu) and civil (CPu) plutonium based fuel cycles. (author)

[en] The present book contains the proceedings of the 4. workshop of a series of meetings, previously held in Seyssins in 1994 and 1998 and in Cadarache in 2005. In the years following the last conference strong progress in our field has been made in several domains in fission research, in particular in medium and high energy fission, in fission properties of the highest elements, in the spectroscopic investigation of neutron rich fission products, in fission fragment distributions, and in neutron emission. This progress is much due to better detection devices and theoretical developments, and to a strong incentive towards a better understanding of the fission process. Since the last meeting evolutions of the energy policies could be observed all around the world. Such adjustments are due to both, serious difficulties in the fossil fuels supply and a much stronger awareness of the environmental problems. In France, important laws were voted in 2005 and 2006 confirming a clear policy based on sustainable energy generation where nuclear fission plays a major role. At the European level the 'Sustainable Nuclear Energy Platform' was launched and more generally, a revival of the nuclear power could be observed in many countries. In order to be able to contribute in the future even more than it does today to the energy needs of the planet, and in particular with new generation reactors, nuclear fission will evolve in both economical and technical terms. We think that, as in the past, progress must imply a very strong link between fundamental and applied research based on experimental and theoretical approaches. In this context we tried to gather in this workshop the different nuclear communities studying the fission process, including the following topics: - nuclear fission experiments, - spectroscopy of neutron rich nuclei, - fission data evaluation, - theoretical aspects of nuclear fission, - and innovative nuclear systems and new facilities. About 100 scientists from 17 different countries attended the conference in the friendly working atmosphere of the Castle of Cadarache in the heart of Provence. During the workshop the most recent achievements in these different fields were discussed. The meeting clearly profited from the exchange of information and from discussions among these different communities. In addition, an after dinner talk by Ph. Garderet (AREVA) gave an interesting view of the industrial needs. The scientific program was suggested by the International Advisory Committee and we would like to thank our colleagues for this crucial help. This workshop would not have been possible without the efficient organization from Mrs. Veronique Diodovich and Mrs. Angelika Taffut, and the kind hospitality and the very professional help of Mrs. Brigitte Le Fur, the Cadarache Center and of the Castle of Cadarache. This workshop was sponsored by the Commissariat a l'Energie Atomique (Bruyeres-le- Chatel, Cadarache and Saclay), by the Institut Laue-Langevin (ILL), by the Grand Accelerateur National d'Ions Lourds (GANIL), by AREVA, by CANBERRA, by Heinziger Electronics, by the Regional Council of Provence Alpes Cote d'Azur and the Ministry of Research and Higher Education

[en] A comprehensive theoretical model is proposed to explain the functioning of fission chambers operated in current mode, even in very high neutron fluxes. The calibration curves are calculated as a function of basic physical parameters as fission rate, gas pressure and geometry of the chambers. The output current at saturation is precisely calculated, as well as the maximum voltage to be applied in order to avoid avalanche phenomena. The electric field distortion due to the space charge phenomena is also estimated. Within this model, the characteristic responses of fission chambers are correctly reproduced, in agreement with the experience feedback obtained at the ILL/Grenoble High-Flux Reactor

[en] The present book contains the proceedings of the third workshop in a series of workshops previously held in Seyssins in 1994 and 1998. The meeting was jointly organized by different divisions of CEA and two major international laboratories. In the opening address, Prof. B. Bigot, the French High Commissioner for Atomic Energy, outlined France's energy policy for the next few decades. He emphasized the continuing progress of nuclear fission in both technical and economic terms, allowing it to contribute to the energy needs of the planet even more in the future than it does today. Such progress implies a very strong link between fundamental and applied research based on experimental and theoretical approaches. The workshop gathered the different nuclear communities studying the fission process, including topics as the following: - nuclear fission experiments, - spectroscopy of neutron rich nuclei, - fission data evaluation, - theoretical aspects of nuclear fission, - and innovative nuclear systems and new facilities. The scientific program was suggested by an International Advisory Committee. About 100 scientists from 13 different countries attended the conference in the friendly working atmosphere of the Castle of Cadarache in the heart of the Provence. The proceedings of the workshop were divided into 11 sections addressing the following subject matters: 1. Cross sections and resonances (5 papers); 2. Fission at higher energies - I (5 papers); 3. Fission: mass and charge yields (4 papers); 4. Light particles and cluster emission (4 papers); 5. Spectroscopy of neutron rich nuclei (5 papers); 6. Resonances, barriers, and fission times (5 papers); 7. Fragment excitation and neutron emission (4 papers); 8. Mass and energy distributions (4 papers); 9. Needs for nuclear data and new facilities - I (4 papers); 10. Angular momenta and fission at higher Energies - II (3 papers); 11. New facilities - II (2 papers). A poster session of 8 presentations completed the workshop

[en] Ternary events in the thermal neutron induced fission of ²⁴¹Pu were studied with the recoil separator LOHENGRIN at the Institut Laue Langevin in Grenoble. Yields and energy distributions could be determined for most isotopes of the elements hydrogen to oxygen. Also several heavier nuclei up to ³⁰Mg could be observed. Yields were measured for 42 isotopes, for further 17 isotopes upper limits could be deduced. For the first time the halo nuclei ¹¹Li and ¹⁴Be were found in neutron induced fission with yields of some 10^-10 per fission. This is orders of magnitude lower than predicted by most of the ternary fission models

[en] The neutronic performances of the MEGAPIE target will be studied using fission micro-chambers specially designed to stand the severe irradiation conditions of flux and temperature. The absolute neutron flux will be monitored on-line at different positions inside the target in order to studied its spatial and temporal variations. Together with the flux characterisation, actinide incineration potential of such target will be study through ²⁴¹Am and ²³⁷Np isotopes. Prototype fission detectors and electronics have been successfully tested during the past three years at the High Flux Reactor of Laue Langevin Institute. The results of these tests are presented

[en] Proposed by representatives of the main involved companies, agencies and institutions, the contributions of this colloquium addressed the following issues: the role of new energy technologies in the French and World sustainable development; The programmes 'New energy technologies'; Research priorities for these new technologies; Industry Perspectives and challenges; SMEs and the ANR; Research perspectives and challenges (electrochemical storage of energy, solar photovoltaic energy, new materials for energy, integration of renewable energies in electric systems, technological innovations for new energy technologies)