1,471,521 research outputs found
Search for Bremsstrahlung radiation in quasi-free n p --> n p gamma reactions
Due to the high sensitivity of the N N --> N N gamma reaction to the
nucleon-nucleon potential, Bremsstrahlung radiation is used as a tool to
investigate details of the nucleon-nucleon interaction. Such investigations can
be performed at the cooler synchrotron COSY in the Research Centre Juelich, by
dint of the COSY-11 detection system. The results of the identification of
Bremsstrahlung radiation emitted via the d p --> d p gamma reaction in data
taken with a proton target and a deuteron beam are presented and discussed.Comment: 3 pages; Presented at Meson 2004: 8th International Workshop on Meson
Production, Properties and Interaction, Krakow, Poland, 4-8 June 2004;
Submitted to International Journal of Modern Physics
(N,p,q) Harmonic Superspace
A family of harmonic superspaces associated with four-dimensional spacetime
is described. Some applications to supersymmetric field theories, including
supergravity, are given.Comment: 25 pages, latex file, improved. Minor text errors correcte
N,N'-(p-Phenylene)dibenzamide (PPDB)
C20N202H16, monoclinic, P2~/c, a = 18.065(1), b = 5.247(1), c = 8.027(1) A, fl = 93.99 (1) °, Z = 2. The crystal structure has been refined by least-squares techniques. R w = 7.3%. The structure contains planar phenyl rings which are\ud
rotated with respect to the plane of the amide group owing to steric hindrance. The molecules are connected in one dimension by means of hydrogen bonds
Semiclassical magnetotransport in graphene n-p junctions
We provide a semiclassical description of the electronic transport through
graphene n-p junctions in the quantum Hall regime. This framework is known to
experimentally exhibit conductance plateaus whose origin is still not fully
understood. In the magnetic regime (E < vF B), we show the conductance of
excited states is essentially zero, while that of the ground state depends on
the boundary conditions considered at the edge of the sample. In the electric
regime (E > vF B), for a step-like electrostatic potential (abrupt on the scale
of the magnetic length), we derive a semiclassical approximation for the
conductance in terms of the various snake-like trajectories at the interface of
the junction. For a symmetric configuration, the general result can be
recovered using a simple scattering approach, providing a transparent analysis
of the problem under study. We thoroughly discuss the semiclassical predicted
behavior for the conductance and conclude that any approach using fully
phase-coherent electrons will hardly account for the experimentally observed
plateaus.Comment: 22 pages, 19 figure
Performance and temperature dependencies of proton irradiated n/p GaAs and n/p silicon cells
The n/p homojunction GaAs cell is found to be more radiation resistant than p/nheteroface GaAs under 10 MeV proton irradiation. Both GaAs cell types outperform conventional silicon n/p cells under the same conditions. An increase temperature dependency of maximum power for the GaAs n/p cells is attributed largely to differences in Voc between the two GaAs cell types. These results and diffusion length considerations are consistent with the conclusion that p-type GaAs is more radiation resistant than n-type and therefore that the n/p configuration is possibly favored for use in the space radiation environment. However, it is concluded that additional work is required in order to choose between the two GaAs cell configurations
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