3,715 research outputs found
The Vlasov-Poisson system with radiation damping
We set up and analyze a model of radiation damping within the framework of
continuum mechanics, inspired by a model of post-Newtonian hydrodynamics due to
Blanchet, Damour and Schaefer. In order to simplify the problem as much as
possible we replace the gravitational field by the electromagnetic field and
the fluid by kinetic theory. We prove that the resulting system has a
well-posed Cauchy problem globally in time for general initial data and in all
solutions the fields decay to zero at late times. In particular, this means
that the model is free from the runaway solutions which frequently occur in
descriptions of radiation reaction
Cavity reactor critical experiment, volume 3
Cavity reactor critical experiment - volume
Simplified models of electromagnetic and gravitational radiation damping
In previous work the authors analysed the global properties of an approximate
model of radiation damping for charged particles. This work is put into context
and related to the original motivation of understanding approximations used in
the study of gravitational radiation damping. It is examined to what extent the
results obtained previously depend on the particular model chosen. Comparisons
are made with other models for gravitational and electromagnetic fields. The
relation of the kinetic model for which theorems were proved to certain
many-particle models with radiation damping is exhibited
Gas cavity reactor simulation experiment final report
Gaseous cavitation reactor simulation experiment using uranium fluoride fue
Cavity reactor critical experiment, volume 4 (waves and control methods)
Fuel wave formation and control in coaxial flowing gas cavity reactor for space nuclear propulsio
Experimental rate coefficients for collisional excitation of lithium-like ions
Collisional excitation rates for lithium-like ions derived from diagnosed plasma produced in theta pinch device and line intensities emitted by these ion
Flowing gas, non-nuclear experiments on the gas core reactor
Flow tests were conducted on models of the gas core (cavity) reactor. Variations in cavity wall and injection configurations were aimed at establishing flow patterns that give a maximum of the nuclear criticality eigenvalue. Correlation with the nuclear effect was made using multigroup diffusion theory normalized by previous benchmark critical experiments. Air was used to simulate the hydrogen propellant in the flow tests, and smoked air, argon, or freon to simulate the central nuclear fuel gas. All tests were run in the down-firing direction so that gravitational effects simulated the acceleration effect of a rocket. Results show that acceptable flow patterns with high volume fraction for the simulated nuclear fuel gas and high flow rate ratios of propellant to fuel can be obtained. Using a point injector for the fuel, good flow patterns are obtained by directing the outer gas at high velocity along the cavity wall, using louvered or oblique-angle-honeycomb injection schemes
Perturbation of strong Feller semigroups and well-posedness of semilinear stochastic equations on Banach spaces
We prove a Miyadera-Voigt type perturbation theorem for strong Feller
semigroups. Using this result, we prove well-posedness of the semilinear
stochastic equation dX(t) = [AX(t) + F(X(t))]dt + GdW_H(t) on a separable
Banach space E, assuming that F is bounded and measurable and that the
associated linear equation, i.e. the equation with F = 0, is well-posed and its
transition semigroup is strongly Feller and satisfies an appropriate gradient
estimate. We also study existence and uniqueness of invariant measures for the
associated transition semigroup.Comment: Revision based on the referee's comment
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