155,914 research outputs found
Some contributions to the theory of edge waves
A new theory of edge waves over a slowly varying depth
Excitation energies, polarizabilities, multipole transition rates, and lifetimes of ions along the francium isoelectronic sequence
Relativistic many-body perturbation theory is applied to study properties of
ions of the francium isoelectronic sequence. Specifically, energies of the 7s,
7p, 6d, and 5f states of Fr-like ions with nuclear charges Z = 87 - 100 are
calculated through third order; reduced matrix elements, oscillator strengths,
transition rates, and lifetimes are determined for 7s - 7p, 7p - 6d, and 6d -
5f electric-dipole transitions; and 7s - 6d, 7s - 5f, and 5f_5/2 - 5f_7/2
multipole matrix elements are evaluated to obtain the lifetimes of low-lying
excited states. Moreover, for the ions Z = 87 - 92 calculations are also
carried out using the relativistic all-order single-double method, in which
single and double excitations of Dirac-Fock wave functions are included to all
orders in perturbation theory. With the aid of the SD wave functions, we obtain
accurate values of energies, transition rates, oscillator strengths, and the
lifetimes of these six ions. Ground state scalar polarizabilities in Fr I, Ra
II, Ac III, and Th IV are calculated using relativistic third-order and
all-order methods. Ground state scalar polarizabilities for other Fr-like ions
are calculated using a relativistic second-order method. These calculations
provide a theoretical benchmark for comparison with experiment and theory.Comment: 13 figures, 11 table
Excitation energies, polarizabilities, multipole transition rates, and lifetimes in Th IV
Excitation energies of the ns_{1/2} (n=7-10), np_j (n=7-9), nd_j (n=6-8),
nf_{j} (n=5-7), and ng_{j} (n=5-6) states in Th IV are evaluated. First-,
second-, third-, and all-order Coulomb energies and first- and second-order
Coulomb-Breit energies are calculated. Reduced matrix elements, oscillator
strengths, transition rates, and lifetimes are determined for the 96 possible
nl_j-n'l'_j' electric-dipole transitions. Multipole matrix elements
(7s_{1/2}-6d_j, 7s_{1/2}-5f_j, and 5f_{5/2}-5f_{7/2}) are evaluated to obtain
the lifetimes of the and 7s_{1/2}$ states. Matrix elements are
calculated using both relativistic many-body perturbation theory, complete
through third order, and a relativistic all-order method restricted to single
and double (SD) excitations. Scalar and tensor polarizabilities for the
5f_{5/2} ground state in Th3+ are calculated using relativistic third-order and
all-order methods. These calculations provide a theoretical benchmark for
comparison with experiment and theory.Comment: 9 pages, 9 figure
Brazing process using'al-Si filler alloy reliably bonds aluminum parts
Brazing process employs an aluminum-silicon filler alloy for diffusion bonding of aluminum parts in a vacuum or inert gas atmosphere. This process is carried out at temperatures substantially below those required in conventional process and produces bonds of greater strength and reliability
Film annotation system for a space experiment
This microprocessor system was designed to control and annotate a Nikon 35 mm camera for the purpose of obtaining photographs and data at predefined time intervals. The single STD BUSS interface card was designed in such a way as to allow it to be used in either a stand alone application with minimum features or installed in a STD BUSS computer allowing for maximum features. This control system also allows the exposure of twenty eight alpha/numeric characters across the bottom of each photograph. The data contains such information as camera identification, frame count, user defined text, and time to .01 second
Sterilizable wide angle gas bearing gyro FGG334S Quarterly progress report, Jul. 1 - Oct. 1, 1967
Vibration and shock testing for spin motors for sterilizable wide angle gas bearing gyr
Helical channel design and technology for cooling of muon beams
Novel magnetic helical channel designs for capture and cooling of bright muon
beams are being developed using numerical simulations based on new inventions
such as helical solenoid (HS) magnets and hydrogen-pressurized RF (HPRF)
cavities. We are close to the factor of a million six-dimensional phase space
(6D) reduction needed for muon colliders. Recent experimental and simulation
results are presented.Comment: 6 pp. 14th Advanced Accelerator Concepts Workshop 13-19 Jun 2010:
Annapolis, Marylan
What is a quantum simulator?
Quantum simulators are devices that actively use quantum effects to answer
questions about model systems and, through them, real systems. Here we expand
on this definition by answering several fundamental questions about the nature
and use of quantum simulators. Our answers address two important areas. First,
the difference between an operation termed simulation and another termed
computation. This distinction is related to the purpose of an operation, as
well as our confidence in and expectation of its accuracy. Second, the
threshold between quantum and classical simulations. Throughout, we provide a
perspective on the achievements and directions of the field of quantum
simulation.Comment: 13 pages, 2 figure
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