3,756 research outputs found
Improved magnesia for thermal control coatings
Formation of radiation-generated color centers using single crystals of magnesium oxide is discussed. Crystal structure of magnesium oxide is described. Chemical processes used to produce magnesium oxide with desired color center kinetics are presented. Proton irradiation of magnesium oxide crystals was conducted to determine lattice defects
Subroutine allows easy computation in extended precision arithmetic
Subroutine called NPREC allows relatively simple computation of very large numbers or very small fractions with extreme accuracy. This subroutine handles numbers that consist of 35 binary bits /1 word/ for the exponent and 70 bits /2 words/ for the fraction
Study of color center formation in white powder compounds
White powder compounds of metal oxides for thermal protective coating of spacecraf
Pumped quantum systems: immersion fluids of the future?
Quantum optical techniques may yield immersion fluids with high indices of
refraction without absorption. We describe one such technique in which a probe
field experiences a large index of refraction with amplification rather than
absorption, and examine its practicality for an immersion lithography
application. Enhanced index can be observed in a three-level system with a
tunable, near-resonant, coherent probe and incoherent pump field that inverts
population of the probe transition. This observation contradicts the common
belief that large indices of refraction are impossible without absorption,
however it is well in accord with existing electromagnetic theory and practice.
Calculations show that a refractive index >> 2 is possible with practical
experimental parameters. A scheme with an incoherent mixture of pumped and
unpumped atoms is also examined, and is seen to have a lower refractive index
(~2) accompanied by neither gain nor loss.Comment: 6 pages, 7 figures, accepted for publication in J. Vac. Sci. Tech. B,
Nov/Dec 2005 (full reference not known yet
Evaluation of the Acute Abdominal Crisis in the Equine
When presented with a horse in acute abdominal distress the practitioner must choose between various medical or surgical treatments. This decision should be based on the patient\u27s history, the results of a thorough systemic examination, clinical pathology findings, and the response to various treatments. The ability to evaluate and use this data to institute the proper regimen of therapy early in the course of the disease will help to increase the chances of recovery
Mach-Zehnder Interferometry in a Strongly Driven Superconducting Qubit
We demonstrate Mach-Zehnder-type interferometry in a superconducting flux
qubit. The qubit is a tunable artificial atom, whose ground and excited states
exhibit an avoided crossing. Strongly driving the qubit with harmonic
excitation sweeps it through the avoided crossing two times per period. As the
induced Landau-Zener transitions act as coherent beamsplitters, the accumulated
phase between transitions, which varies with microwave amplitude, results in
quantum interference fringes for n=1...20 photon transitions. The
generalization of optical Mach-Zehnder interferometry, performed in qubit phase
space, provides an alternative means to manipulate and characterize the qubit
in the strongly-driven regime.Comment: 14 pages, 6 figure
Non-Simplified SUSY: Stau-Coannihilation at LHC and ILC
If new phenomena beyond the Standard Model will be discovered at the LHC, the
properties of the new particles could be determined with data from the
High-Luminosity LHC and from a future linear collider like the ILC. We discuss
the possible interplay between measurements at the two accelerators in a
concrete example, namely a full SUSY model which features a small stau_1-LSP
mass difference. Various channels have been studied using the Snowmass 2013
combined LHC detector implementation in the Delphes simulation package, as well
as simulations of the ILD detector concept from the Technical Design Report. We
investigate both the LHC and ILC capabilities for discovery, separation and
identification of various parts of the spectrum. While some parts would be
discovered at the LHC, there is substantial room for further discoveries at the
ILC. We finally highlight examples where the precise knowledge about the lower
part of the mass spectrum which could be acquired at the ILC would enable a
more in-depth analysis of the LHC data with respect to the heavier states.Comment: 42 pages, 18 figures, 12 table
Effects of accidental microconstriction on the quantized conductance in long wires
We have investigated the conductance of long quantum wires formed in
GaAs/AlGaAs heterostructures. Using realistic fluctuation potentials from donor
layers we have simulated numerically the conductance of four different kinds of
wires. While ideal wires show perfect quantization, potential fluctuations from
random donors may give rise to strong conductance oscillations and degradation
of the quantization plateaux. Statistically there is always the possibility of
having large fluctuations in a sample that may effectively act as a
microconstriction. We therefore introduce microconstrictions in the wires by
occasional clustering of donors. These microconstrictions are found to restore
the quantized plateaux. A similar effect is found for accidental lithographic
inaccuracies.Comment: 4 pages, 2 figures, paper for NANO2002 symposium, will appear in SPIE
proceeding
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