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In this article measured time-of-flight spectra and energy spectra of a water moderator operated at various temperatures between 20K and room temperature are described. These data are used to validate generated and processed neutron scattering law data. It was possible to simulate the leakage spectrum of a water moderator at cryogenic temperatures and compare it with experimental results.

Proc on line; International audience; The status of the Joint Evaluated Fission and Fusion file (JEFF) is described. JEFF-3.1 comprises a significant update of actinide evaluations, materials evaluations that have emerged from various European nuclear data projects, the activation library JEFF-3.1/A, the decay data and fission yield sub-libraries, and fusion-related data files from the EFF project. The revisions were motivated by the availability of new measurements, modelling capabilities and trends from integral experiments. Validations have been performed, mainly for criticality, reactivity temperature coefficients, fuel inventory and shielding of thermal and fast systems. Compared with earlier releases, JEFF-3.1 provides improved performance with respect to a variety of scientific and industrial applications. Following on from the public release of JEFF-3.1, the French nuclear power industry has selected this suite of nuclear applications libraries for inclusion in their production codes.

For the relevant materials used in cold and superthermal neutron sources the database for design studies was considerably improved. For D 2 O at room temperature the intra and inter molecular interaction with neutrons were included using realistic structure factors S ( κ ). These effects are also taken into account for the cold moderators liquid H 2 and D 2 by deriving improved S ( κ ). The neutron interaction in solid materials and neutron filters as Al, Pb and Bi is treated exactly at low temperatures, especially for coherent neutron scattering in the tetragonal and FCC lattices. For superfluid 4 He cross-section data for ultracold neutron production were derived as well as data for neutron transport considering diffusive motions and intermolecular scattering. Validation of the generated cross-sectional data was realized by comparison with differential and integral neutron scattering experiments so far available. These thermal neutron data can be used for both multigroup S N and Monte-Carlo methods solving the neutron transport equation.

Exponential growth in leakage power density with physical scaling is driving ULSI technology towards innovative device architectures. Double-gate CMOS (DGCMOS), achieved through use of the Delta Device (D.Hisamoto et al, IEDM 1989, p.833-836), or FinFET (X.Huang et al, IEDM 1999, p.67-70), provides both a tactical solution to the gate-leakage challenge and a strategic scaling advantage. FinFET fabrication is very close to that of the conventional CMOS process, with only minor disruptions, yielding the potential for a rapid deployment to manufacturing. Planar circuit designs have been converted to FinFET-DGCMOS without disruption to physical area.

For the validation of the recently released evaluated nuclear data files JEF-2 and ENDF/B-VI a first set of benchmark calculations for thermal systems important for criticality safety and LWR-neutronics were performed and compared with corresponding calculations based on JEF-1 and the MCNP-3B library (ENDF/B-IV, ENDL-85). The processing of the JEF-2 and ENDF/B-VI data which are given in the ENDF-6 format was performed by an updated version of the nuclear data processing system NJOY. Both multigroup libraries with 316 groups in MATXS-format and MCNP-libraries (continuous data with a very fine energy resolution) based on JEF-2 and ENDF /B-VI were generated. The ORNL uranyl nitrate benchmarks as well as the PNL Pu nitrate benchmarks were analysed by deterministic (ANISN/ONEDANT-S N -method) and Monte Carlo methods (MCNP-3B). The group constants for the S N -calculations were generated by a combination of TRAMIX and RSYST/CGM.

Scattering laws S(α,β) were derived in ENDF-6 format for the most important materials as liquid H2, D2, 4He and solid Be, Bi used in cold and superthermal neutron sources by considering the incoherent as well as the coherent scattering dynamics at working temperature. For cold and superthermal neutron source design calculations including the determination of heat production coupled n-γ cross-section matrices and Kerma factors were generated.