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Thin-thick quadrature frequency conversion

Description: The quadrature conversion scheme is a method of generating the second harmonic. The scheme, which uses two crystals in series, has several advantages over single-crystal or other two crystal schemes. The most important is that it is capable of high conversion efficiency over a large dynamic range of drive intensity and detuning angle.
Date: February 7, 1985
Creator: Eimerl, D.
Partner: UNT Libraries Government Documents Department
open access

Difficulties with inferring neutron cross sections from charged-particle reactions

Description: We have investigated problems associated with inferring cross sections for neutron reactions on unstable nuclei in the mass-90 region from charged-particle reactions on nearby stable targets. We conclude that effects due to precompound evaporation, isospin, and multiple reaction paths severely limit the circumstances under which charged-particle studies may be directly and easily converted to neutron cross sections of useful accuracy. 4 refs., 2 figs.
Date: May 7, 1985
Creator: Gardner, D. G. & Gardner, M. A.
Partner: UNT Libraries Government Documents Department
open access

Improvements in the weldability of a superconductor sheath material

Description: This paper investigates the effects of chemistry and heat treatment variation on the 4-K tensile properties of A-286, a candidate sheath material for force-cooled superconductors. Currently, full use of A-286 and similar superalloys is limited by the observed low yield and ultimate tensile strengths in the welded and aged condition. The low strength is shown to be associated with the formation of precipitate-free zones as a result of alloying-element segregation during weld pool solidification.… more
Date: August 7, 1985
Creator: Summers, L.T. & Morris, J.W. Jr.
Partner: UNT Libraries Government Documents Department
open access

Calculational tools for the evaluation of nuclear cross-section and spectra data

Description: A technique based on discrete energy levels rather than energy level densities is presented for nuclear reaction calculations. The validity of the technique is demonstrated via theoretical and experimental agreement for cross sections, isomer-ratios and gamma-ray strength functions. 50 refs., 7 figs. (WRF)
Date: May 7, 1985
Creator: Gardner, M.A.
Partner: UNT Libraries Government Documents Department
open access

Creep of 304 LN and 316 L stainless steels at cryogenic temperatures

Description: Creep behavior of Type 304 LN plate and 316 L shielded-metal-arc (SMA)-deposited stainless weld metal was investigated at 4/sup 0/K. Testing was performed at constant load in a creep machine with a cryostat designed for long-term stability. Both transient and steady-state creep were observed during tests lasting over 2000 hours. Steady-state creep rates were much greater than expected from extrapolations of 300-K creep data. Creep rates on the order of 10/sup -10/ s/sup -1/ were observed at str… more
Date: August 7, 1985
Creator: Roth, L. D.; Manhardt, A. E.; Dalder, E. N. C. & Kershaw, R. P., Jr.
Partner: UNT Libraries Government Documents Department
open access

New harmonic materials: index engineering. Thin-thick quadrature frequency conversion

Description: The quadrature conversion scheme is a method of generating the second harmonic. The scheme, which uses two crystals in series, has several advantages over single-crystal or other two crystal schemes. The most important is that it is capable of high conversion efficiency over a large dynamic range of drive intensity and detuning angle. Consider a pair of KDP crystals cut for type-II phase matching. In the quadrature scheme, the optic axes of the crystals are arranged so that the plans containing… more
Date: February 7, 1985
Creator: Eimerl, D.
Partner: UNT Libraries Government Documents Department
open access

Inversion approach for thermal data from a convecting hydrothermal system. Revision 1

Description: Hydrothermal systems are often studied by collecting thermal gradient data and temperature-depth curves. These data contain important information about the flow field, the evolution of the hydrothermal system, and the location and nature of the ultimate heat sources. Thermal data are conventionally interpreted by the ''forward'' method; the thermal field is calculated based on selected initial conditions and boundary conditions such as temperature and permeability distributions. If the calculat… more
Date: June 7, 1985
Creator: Kasameyer, P.; Younker, L. & Hanson, J.
Partner: UNT Libraries Government Documents Department
open access

Importance of level structure in nuclear reaction cross-section calculations. Revision 1

Description: It is shown that level-density expressions cannot adequately represent or substitute for level structure information when making calculations of the Hauser-Feshbach type for cross sections or isomer-ratios for nuclei in the first few MeV above their ground state. It is stated that such discrete level information should include both experimentally confirmed and theoretically predicted levels. The utility of discrete level information to optimize level density calculations, to compute isomer rati… more
Date: November 7, 1985
Creator: Gardner, M. A. & Gardner, D. G.
Partner: UNT Libraries Government Documents Department
open access

Preliminary results on open accelerating structures

Description: In this paper we consider periodic structures consisting of rows of spherical conductors. In a plasma linac, these spherical conductors would be formed from liquid droplets on whose surfaces a plasma would be formed. For this paper, the field configurations have been investigated using copper spheres approximately 11 cm diameter and microwave radiation of approximately 30 cm wavelength. No suitable accelerating mode was found for relativistic particles using a single row of spheres, but with tw… more
Date: January 7, 1985
Creator: Palmer, R. B. & Giordano, S.
Partner: UNT Libraries Government Documents Department
open access

Resolvability of positron decay channels

Description: Many data analysis treatments of positron experiments attempt to resolve two or more positron decay or exist channels which may be open simultaneously. Examples of the need to employ such treatments of the experimental results can be found in the resolution of the constituents of a defect ensemble, or in the analysis of the complex spectra which arise from the interaction of slow positrons at or near the surfaces of solids. Experimental one- and two-dimensional angular correlation of annihilati… more
Date: March 7, 1985
Creator: Fluss, M.J.; Howell, R.H.; Rosenberg, I.J. & Meyer, P.
Partner: UNT Libraries Government Documents Department
open access

Same-Sign Dilepton Production by Neutrinos

Description: There has been considerable experimental work on same-sign dilepton production in neutrino interactions over the past 10 years. However, the situation is still unclear. Most experiments do have evidence for an excess of candidates but there is a lack of independent statistically significant results. Present experiments at the Tevatron may provide important new information. However the recent revision of older results and the lower rates from recent experiments indicate that real progress will b… more
Date: November 7, 1985
Creator: Murtagh, Michael J.
Partner: UNT Libraries Government Documents Department
open access

Recent developments in thermoluminescence kinetics: applications to other thermally stimulated processes

Description: Recent thermoluminescence (TL) studies indicate that many kinetic properties are not in accord with the well known 1st and 2nd order TL kinetic equations. For example, the usual equations do not describe: (1) the shape of certain single glow peaks. (2) The shape of glow peaks in many glow curves containing more than one glow peak. (3) The dependence of the peak temperature, the FWHM, the shape, and other properties on the pre-measurement dose. However, the properties of some single glow peaks a… more
Date: August 7, 1985
Creator: Levy, P.W.
Partner: UNT Libraries Government Documents Department
open access

High Brightness Test Stand

Description: The High Brightness Test Stand is a 2 MeV, less than or equal to 10 kA electron accelerator module. This accelerator module, designed as an upgrade prototype for the Advanced Test Accelerator (ATA), combines solid state nonlinear magnetic drives with state-of-the-art induction linac technology. The facility serves a dual role, as it not only provides a test bed for this new technology, but is used to develop high brightness electron optics. We will both further describe the accelerator, as well… more
Date: August 7, 1985
Creator: Birx, D. L.; Caporaso, G. J.; Boyd, J. K.; Hawkins, S. A.; Poor, S. E.; Reginato, L. L. et al.
Partner: UNT Libraries Government Documents Department
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