Cavity reactor critical experiment, volume 3

Cavity reactor critical experiment - volume

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

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

Feasibility study of full-reactor gas core demonstration test

Separate studies of nuclear criticality, flow patterns, and thermodynamics for the gas core reactor concept have all given positive indications of its feasibility. However, before serious design for a full scale gas core application can be made, feasibility must be shown for operation with full interaction of the nuclear, thermal, and hydraulic effects. A minimum sized, and hence minimum expense, test arrangement is considered for a full gas core configuration. It is shown that the hydrogen coolant scattering effects dominate the nuclear considerations at elevated temperatures. A cavity diameter of somewhat larger than 4 ft (122 cm) will be needed if temperatures high enough to vaporize uranium are to be achieved

What Fraction of the Young Clusters in the Antennae Galaxies are "Missing"?

A reexamination of the correspondence between 6 cm radio continuum sources and young star clusters in the Antennae galaxies indicates that 85 % of the strong thermal sources have optical counterparts, once the optical image is shifted 1.2 arcsec to the southwest. A sample of 37 radio-optical matches are studied in detail showing correlations between radio properties and a variety of optical characteristics. There is a strong correlation between the radio flux and the intrinsic optical brightness. In particular, the brightest radio source is also the intrinsically brightest optical cluster (WS80). It is also the most extincted cluster in the sample, the strongest CO source and the strongest 15 micron source . Furthermore, the brightest ten radio sources are all amongst the youngest clusters with ages in the range 0 - 4 Myr and extinctions from A_V = 0.5 to 7.6 mag (with a median value of 2.6 mag). Only a few of the very red clusters originally discovered by Whitmore & Schweizer are radio sources, contrary to earlier suggestions. Finally, a new hybrid method of determining cluster ages has been developed using both UBVI colors and H_alpha equivalent widths to break the age-reddening degeneracy.Comment: 51 pages, 13 postscript figures, LaTex. To appear in the Astronomical Journal, 124, 2002, Septembe

Cavity Reactor Engineering Mockup Critical Experiment

Critical mass of uranium 235 for stainless steel lined cavities in nuclear research and test reactors with heavy water reflecto

Primordial magnetic fields and nonlinear electrodynamics

The creation of large scale magnetic fields is studied in an inflationary universe where electrodynamics is assumed to be nonlinear. After inflation ends electrodynamics becomes linear and thus the description of reheating and the subsequent radiation dominated stage are unaltered. The nonlinear regime of electrodynamics is described by lagrangians having a power law dependence on one of the invariants of the electromagnetic field. It is found that there is a range of parameters for which primordial magnetic fields of cosmologically interesting strengths can be created.Comment: 21 pages, 3 figure

Can be gravitational waves markers for an extra-dimension?

The main issue of the present letter is to fix specific features (which turn out being independent of extradimension size) of gravitational waves generated before a dimensional compactification process. Valuable is the possibility to detect our prediction from gravitational wave experiment without high energy laboratory investigation. In particular we show how gravitational waves can bring information on the number of Universe dimensions. Within the framework of Kaluza-Klein hypotheses, a different morphology arises between waves generated before than the compactification process settled down and ordinary 4-dimensional waves. In the former case the scalar and tensor degrees of freedom can not be resolved. As a consequence if were detected gravitational waves having the feature here predicted (anomalous polarization amplitudes), then they would be reliable markers for the existence of an extra dimension.Comment: 5 pages, two figure, to appear on Int. Journ. Mod. Phys.

The Geoff Egan Memorial Lecture 2011. Artefacts, art and artifice: reconsidering iconographic sources for archaeological objects in early modern Europe

A first systematic analysis of historic domestic material culture depicted in contemporaneous Western painting and prints, c.1400-1800. Drawing on an extensive data set, the paper proposes to methodologies and hermeneutics for historical analysis and archaeological correspondence