properties of low-index laser materials (open access)

properties of low-index laser materials

Measurements of n/sub 2/ for a large class of oxide and fluoride crystals and glasses have been made using 100-ps, 1.06-..mu..m laser pulses and time-resolved interferometry. Values of n/sub 2/ for various glasses are summarized.
Date: May 9, 1980
Creator: Weber, M. J.
Object Type: Report
System: The UNT Digital Library
Analytical methods of electrode design for a relativistic electron gun (open access)

Analytical methods of electrode design for a relativistic electron gun

The standard paraxial ray equation method for the design of electrodes for an electrostatically focused gun is extended to include relativistic effects and the effects of the beam's azimuthal magnetic field. Solutions for parallel and converging beams are obtained and the predicted currents are compared against those measured on the High Brightness Test Stand. 4 refs., 2 figs.
Date: May 9, 1985
Creator: Caporaso, G.J.; Cole, A.G. & Boyd, J.K.
Object Type: Article
System: The UNT Digital Library
Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations (open access)

Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations

A conceptual heat transfer loop and balance of plant design for the Pulse*Star Inertial Confinement Fusion Reactor has been investigated and results are presented. The Pulse*Star reaction vessel, a perforated steel bell jar approximately 11 m in diameter, is immersed in Li/sub 17/Pb/sub 83/ coolant which flows through the perforations and forms a 1.5 m thick plenum of droplets around an 8 m diameter inner chamber. The reactor and associated pumps, piping, and steam generators are contained within a 17 m diameter pool of Li/sub 17/Pb/sub 83/ coolant to minimize structural requirements and occupied space, resulting in reduced cost. Four parallel heat transfer loops with flow rates of 5.5 m/sup 3//s each are necessary to transfer 3300 MWt of power. The steam generator design was optimized by finding the most cost-effective combination of heat exchanger area and pumping power. Power balance calculations based on an improved electrical conversion efficiency revealed a net electrical output of 1260 MWe to the bus bar and a resulting net efficiency of 39%. Suggested balance-of-plant layouts are also presented.
Date: May 9, 1984
Creator: McDowell, M. W. & Murray, K. A.
Object Type: Report
System: The UNT Digital Library
Numerical simulation of an accelerator injector (open access)

Numerical simulation of an accelerator injector

Accelerator injector designs have been evaluated using two computer codes. The first code self consistently follows relativistic particles in two dimensions. Fields are obtained in the Darwin model which includes inductive effects. This code is used to study cathode emission and acceleration to full injector voltage. The second code transports a fixed segment of a beam along the remainder of the beam line. Using these two codes the effects of electrode configuration on emittance, beam quality and beam transport have been studied.
Date: May 9, 1985
Creator: Boyd, J.K.; Caporaso, G.J. & Cole, A.G.
Object Type: Article
System: The UNT Digital Library
Brightness measurements on the Livermore high brightness test stand (open access)

Brightness measurements on the Livermore high brightness test stand

Several techniques using small radius collimating pipes with and without axial magnetic fields to measure the brightness of an extracted 1 - 2 kA, 1 - 1.5 MeV electron beam will be described. The output beam of the High Brightness Test Stand as measured by one of these techniques is in excess of 2 x 10/sup 5/ amp/cm/sup 2//steradian. 5 refs., 4 figs.
Date: May 9, 1985
Creator: Caporaso, G.J. & Birx, D.L.
Object Type: Article
System: The UNT Digital Library
Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria (open access)

Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria

Calculations of non-inductive current drive typically have been used with model MHD equilibria which are independently generated from an assumed toroidal current profile or from a fit to an experiment. Such a method can lead to serious errors since the driven current can dramatically alter the equilibrium and changes in the equilibrium B-fields can dramatically alter the current drive. The latter effect is quite pronounced in LH current drive where the ray trajectories are sensitive to the local values of the magnetic shear and the density gradient. In order to overcome these problems, we have modified a LH simulation code to accommodate elongated plasmas with numerically generated equilibria. The new LH module has been added to the ACCOME code which solves for current drive by neutral beams, electric fields, and bootstrap effects in a self-consistent 2-D equilibrium. We briefly describe the model in the next section and then present results of a study of LH current drive in ITER. 2 refs., 6 figs., 2 tabs.
Date: May 9, 1989
Creator: Blackfield, D. T.; Devoto, R. S.; Fenstermacher, M. E.; Bonoli, P. T.; Porkolab, M. & Yugo, J.
Object Type: Article
System: The UNT Digital Library
New concepts for drift pumping a thermal barrier with rf (open access)

New concepts for drift pumping a thermal barrier with rf

Pump neutral beams, which are directed into the loss cone of the TMX-U plugs, are normally used to pump ions from the thermal barriers. Because these neutral beams introduce cold gas that reduces pumping efficiency, and require a straight line entrance and exit from the plug, alternate methods are being investigated to provide barrier pumping. To maintain the thermal barrier, either of two classes of particles can be pumped. First, the collisionally trapped ions can be pumped directly. In this case, the most promising selection criterion is the azimuthal drift frequency. Second, the excess sloshing-ion density can be removed, allowing the use of increased sloshing-beam density to pump the trapped ions. The selection mechanism in this case is the Doppler-shifted ion-cyclotron resonance of the high-energy sloshing-ions (3 keV less than or equal to U/sub parallel/ less than or equal to 10 keV).
Date: May 9, 1985
Creator: Barter, J.D.; Baldwin, D.; Chen, Y. & Poulsen, P.
Object Type: Article
System: The UNT Digital Library
Neutron flux, spectrum, and dose equivalent measurements for a 4500-W(th) /sup 238/PuO/sub 2/ general purpose heat source (open access)

Neutron flux, spectrum, and dose equivalent measurements for a 4500-W(th) /sup 238/PuO/sub 2/ general purpose heat source

The total emission rate is (4.5 +- 0.4) 10/sup 7/ n/s, and the average neutron energy is (1.64 +- 0.07) MeV. The factor for converting from neutron fluence to dose equivalent for this spectrum is (3.10 +- 0.24) 10/sup -5/ mRem/n-cm/sup -2/. The factor for converting from neutron fluence to tissue absorbed dose is (3.18 +- 0.26) 10/sup -6/ mRad/n-cm/sup -2/.
Date: May 9, 1985
Creator: Anderson, M.E.
Object Type: Report
System: The UNT Digital Library
Nuclear-data needs for inertial-confinement fusion (ICF) (open access)

Nuclear-data needs for inertial-confinement fusion (ICF)

Our survey was limited to ICF programs in the United States. It included researchers in laser and heavy ion fusion, target design, target diagnostics, and conceptual reactor design. We asked each of these people to read the current data needs for magnetic fusion energy and to comment on additional data that they require.
Date: May 9, 1983
Creator: Haight, R. C. & Motz, H. T.
Object Type: Article
System: The UNT Digital Library
Bremsstrahlung from high Z impurities in hot plasmas (open access)

Bremsstrahlung from high Z impurities in hot plasmas

This is a study of the effect of core electron and plasma screening on Bremsstrahlung from high-Z impurities in hot plasmas. 3 refs., 7 figs., 1 tab.
Date: May 9, 1988
Creator: DeWitt, H.; Rogers, F. & Iglesias, C.
Object Type: Report
System: The UNT Digital Library
Neptunium separations (open access)

Neptunium separations

Two procedures for the separation of Np are presented; the first involves separation of /sup 239/Np from irradiated /sup 238/U, and the second involves separation of /sup 237/Np from a solution representing that from a dissolved fuel element.
Date: May 9, 1983
Creator: Wild, John F.
Object Type: Report
System: The UNT Digital Library
Gas chromatographic separation of hydrogen isotopes using metal hydrides (open access)

Gas chromatographic separation of hydrogen isotopes using metal hydrides

A study was made of the properties of metal hydrides which may be suitable for use in chromatographic separation of hydrogen isotopes. Sixty-five alloys were measured, with the best having a hydrogen-deuterium separation factor of 1.35 at 60/sup 0/C. Chromatographic columns using these alloys produced deuterium enrichments of up to 3.6 in a single pass, using natural abundance hydrogen as starting material. 25 references, 16 figures, 4 tables.
Date: May 9, 1984
Creator: Aldridge, Frederick T.
Object Type: Report
System: The UNT Digital Library
Ground motion - some relative phase measurements in the PEP tunnel (open access)

Ground motion - some relative phase measurements in the PEP tunnel

The spatial as well as the temporal characteristics of ground motion are of interest when one attempts to evaluate orbit distortions resulting from time varying quadrupole displacements. In other words, one needs to know the spatial correlations of quad displacements along the orbits path. A correlation with the betatron wavelength would be, for example, potentially more dangerous than from say purely statistically uncorrelated quad motions. The space versus time relationship of ground motion is, of course, related by the effective velocity of sound in the supporting medium. The medium consists of the ground itself, the tunnel floor and the magnet support structure - the latter two having perhaps transmission line characteristics of their own. The question therefore is: What values of velocity should one use for the various types of disturbances that will be encountered in practice. This note describes the results of a minimal experiment designed to answer two questions:(a) Is it at all possible to measure correlations in an existing tunnel with simple equipment. (b) Are the results consistent with the known geophysical characteristic of the site. The answer to both questions, we believe, is surprisingly, yes.
Date: May 9, 1984
Creator: Fischer, G.E. & Werner, K.
Object Type: Report
System: The UNT Digital Library