4,361 research outputs found
A Density Functional Theory Investigation of Carboranethiol Self-Assembled Monolayer on Au(111)
Isolated and full monolayer adsorption of various carboranethiol
(CBHS) isomers on gold (111) surface have been investigated
using both the standard and van der Waals density functional theoretical
calculations. The effect of differing molecular dipole moment orientations on
the low energy adlayer geometries, the binding characteristics and the
electronic properties of the self-assembled monolayers of these isomers have
been studied. Specifically, the binding energy and work function changes
associated with different molecules show a correlation with their dipole
moments. The adsorption is favored for the isomers with dipole moments parallel
to the surface. Of the two possible unit cell structures, the (55) was
found to be more stable than the ()R23.4 one.Comment: 22 pages, 6 figures and 3 table
Collider design issues based on proton-driven plasma wakefield acceleration
Recent simulations have shown that a high-energy proton bunch can excite
strong plasma wakefields and accelerate a bunch of electrons to the energy
frontier in a single stage of acceleration. It therefore paves the way towards
a compact future collider design using the proton beams from existing
high-energy proton machines, e.g. Tevatron or the LHC. This paper addresses
some key issues in designing a compact electron-positron linear collider and an
electron-proton collider based on existing CERN accelerator infrastructure
An collider based on proton-driven plasma wakefield acceleration
Recent simulations have shown that a high-energy proton bunch can excite
strong plasma wakefields and accelerate a bunch of electrons to the energy
frontier in a single stage of acceleration. This scheme could lead to a future
collider using the LHC for the proton beam and a compact electron
accelerator of length 170 m, producing electrons of energy up to 100 GeV. The
parameters of such a collider are discussed as well as conceptual layouts
within the CERN accelerator complex. The physics of plasma wakefield
acceleration will also be introduced, with the AWAKE experiment, a proof of
principle demonstration of proton-driven plasma wakefield acceleration, briefly
reviewed, as well as the physics possibilities of such an collider.Comment: 6 pages, 2 figures, to appear in the proceedings of the DIS 2014
Workshop, 28 April - 2 May, Warsaw, Polan
Electronic Structure of a Chain-like Compound: TlSe
An ab-initio pseudopotential calculation using density functional theory
within the local density approximation has been performed to investigate the
electronic properties of TlSe which is of chain-like crystal geometry. The
energy bands and effective masses along high symmetry directions, the density
of states and valence charge density distributions cut through various planes
are presented. The results have been discussed in terms of previously existing
experimental and theoretical data, and comparisons with similar compounds have
been made.Comment: 7 page
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