245 research outputs found
3D PROCESS MODELLING ON PERSONAL COMPUTERS
A method for reducing the computation needs of modellingcomplete fabrication processes
for VLSI devices on personal computers in 3 dimensions, a treatment of equitations of basic
physical processes, such as diffusion, oxidation, implantation, etching and deposition is
presented. In the paper we will describe the structure of the TEDI (TechnologyDialog)
program, the main formulas and principles of the models and some examples of 3D process
simulation. The third part of the "TEDI" program (creating a set of control parameters,
automatic simulation and graphical output of results) provides flexible possibilities of
studyingthe connections between 1D, 2D and 3D simulations
Large signal of within the constraints of decays in the 3-3-1 model with neutral leptons
In the framework of the 3-3-1 model with neutral leptons, we have
investigated the lepton-flavor-violating sources based on the Higgs mass
spectrum which has two neutral Higgses identitied with corresponding ones in
the Two-Higgs-Doublet model (THDM). On the scale of the LHC,
we point out the parameter space regions where the experimental limits of decays are satisfied. These regions depend heavily on
the mixing of exotic leptons but are predicted to have large signals. We also show that
can reach a value of .Comment: 30 pages, 9 figure
A spatially and temporally localized sub-laser-cycle electron source
We present an experimental and numerical study of electron emission from a
sharp tungsten tip triggered by sub-8 femtosecond low power laser pulses. This
process is non-linear in the laser electric field, and the non-linearity can be
tuned via the DC voltage applied to the tip. Numerical simulations of this
system show that electron emission takes place within less than one optical
period of the exciting laser pulse, so that an 8 fsec 800 nm laser pulse is
capable of producing a single electron pulse of less than 1 fsec duration.
Furthermore, we find that the carrier-envelope phase dependence of the emission
process is smaller than 0.1% for an 8 fsec pulse but is steeply increasing with
decreasing laser pulse duration.Comment: 4 pages, 5 figure
One-loop contributions to decays and anomalies, and Ward identity
In this paper, we will present analytic formulas to express one-loop
contributions to lepton flavor violating decays , which are
also relevant to the anomalous dipole magnetic moments of charged leptons
. These formulas were computed in the unitary gauge, using the well-known
Passarino-Veltman notations. We also show that our results are consistent with
those calculated previously in the 't Hooft-Veltman gauge, or in the limit of
zero lepton masses. At the one-loop level, we show that the appearance of
fermion-scalar-vector type diagrams in the unitary gauge will violate the Ward
Identity relating to an external photon. As a result, the validation of the
Ward Identity guarantees that the photon always couples with two identical
particles in an arbitrary triple coupling vertex containing a photon.Comment: The version accepted to Nuclear Physics
A Kalman Approach to Lunar Surface Navigation using Radiometric and Inertial Measurements
Future lunar missions supporting the NASA Vision for Space Exploration will rely on a surface navigation system to determine astronaut position, guide exploration, and return safely to the lunar habitat. In this report, we investigate one potential architecture for surface navigation, using an extended Kalman filter to integrate radiometric and inertial measurements. We present a possible infrastructure to support this technique, and we examine an approach to simulating navigational accuracy based on several different system configurations. The results show that position error can be reduced to 1 m after 5 min of processing, given two satellites, one surface communication terminal, and knowledge of the starting position to within 100 m
The role of rainfalls for erosion and sedimentation in the degraded mangroves, Can Gio district, Vietnam
Joint Research on Environmental Science and Technology for the Eart
Rare-earth monosulfides as durable and efficient cold cathodes
In their rocksalt structure, rare-earth monosulfides offer a more stable
alternative to alkali metals to attain low or negative electron affinity when
deposited on various III-V and II-VI semiconductor surfaces. In this article,
we first describe the successful deposition of Lanthanum Monosulfide via pulsed
laser deposition on Si and MgO substrates and alumina templates. These thin
films have been characterized by X-ray diffraction, atomic force microscopy,
high resolution transmission electron microscopy, ellipsometry, Raman
spectroscopy, ultraviolet photoelectron spectroscopy and Kelvin probe
measurements. For both LaS/Si and LaS/MgO thin films, the effective work
function of the submicron thick thin films was determined to be about 1 eV from
field emission measurements using the Scanning Anode Field Emission Microscopy
technique. The physical reasons for these highly desirable low work function
properties were explained using a patchwork field emission model of the
emitting surface. In this model, nanocrystals of low work function materials
having a orientation perpendicular to the surface and outcropping it are
surrounded by a matrix of amorphous materials with higher work function. To
date, LaS thin films have been used successfully as cold cathode emitters with
measured emitted current densities as high as 50 A/cm2. Finally, we describe
the successful growth of LaS thin films on InP substrates and, more recently,
the production of LaS nanoballs and nanoclusters using Pulsed Laser Ablation.Comment: 61 pages, 24 figure
- …