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Application of fast infrared detectors to detonation science (open access)

Application of fast infrared detectors to detonation science

Infrared radiometers have been used to make time-resolved emission measurements of shocked explosives. Instruments of moderate time resolution were used to estimate temperatures in shocked but not detonated explosives. The heterogeneity of the shock-induced heating was discovered in pressed explosives by two-band techniques, and the time-resolved emittance or extent of hot spot coverage indicated a great dependence on shock pressures. Temperatures in moderately shocked organic liquids were also measured. Faster response radiometers with 5 ns rise times based on InSb and HgCdTe photovoltaic detectors were constructed and tested. Preliminary data on reactive shocks and detonations reveal a resolution of the heating in the shock wave and the following reaction.
Date: July 28, 1982
Creator: Von Holle, W. G. & McWilliams, R. A.
System: The UNT Digital Library
Production of glass balloons for laser targets (open access)

Production of glass balloons for laser targets

An apparatus for producing small quantities of glass balloons for use as laser fusion targets is described. To produce precise quantities of the ingredients of one glass balloon, a jet of an aqueous solution of the glass constituents and a blowing agent is metered into uniformly sized drops by Rayleigh breakup. A small fraction of these uniform drops is then passed through an oven where the water is evaporated, the remaining solid material is fused into glass, and a blowing agent decomposes or water of hydration evolves as a vapor to blow the drop into a balloon. Photographs of the resulting glass balloons are presented.
Date: September 28, 1982
Creator: Hendricks, C.D. & Dressler, J.L.
System: The UNT Digital Library
Linear theory radial and nonradial pulsations of DA dwarf stars (open access)

Linear theory radial and nonradial pulsations of DA dwarf stars

The Los Alamos stellar envelope and radial linear non-adiabatic computer code, along with a new Los Alamos non-radial code are used to investigate the total hydrogen mass necessary to produce the non-radial instability of DA dwarfs. (GHT)
Date: July 28, 1982
Creator: Starrfield, S.; Cox, A.N.; Hodson, S. & Pesnell, W.D.
System: The UNT Digital Library
Materials processing in space: ICF target fabrication implications (open access)

Materials processing in space: ICF target fabrication implications

During the last quarter of 1982, the Novette laser will become operational at Lawrence Livermore National Laboratory. The primary characteristics of the Novette laser are shown. In many ways, the new laser will serve as a proving ground and test bed for the Nova laser which is also under construction and should be operational in early 1985. Tables provide the Nova operational characteristics. The advent of the two new lasers, Novette and Nova, will make it possible to study many new and exciting aspects of laser-target interactions and of many implosion physics experiments which have previously not been possible. Some of the most interesting and exciting work will be the exploration of the parameters critical to the ignition of a significant thermonuclear burn in the deuterium-tritium fuel in the targets.
Date: April 28, 1982
Creator: Hendricks, C.D.
System: The UNT Digital Library
Electron energy distributions, vibrational population distributions, and negative-ion concentrations in hydrogen discharges (open access)

Electron energy distributions, vibrational population distributions, and negative-ion concentrations in hydrogen discharges

We consider the negative ion concentrations in hydrogen discharges caused by electron excitation and dissociative attachment processes. The principal formation and destruction processes are discussed for electron densities in the range 10/sup 8/ to 10/sup 13/ electrons cm/sup -3/. Expressions are developed for calculating the high energy portion of the electron energy distribution in the discharge; using these energy distributions the electron excitation rates are evaluated. At low densities, the vibrational distribution arises from singlet electronic excitations and triplet excitations through the /sup 3/..pi../sub u/ state, in equilibrium with wall de-excitation processes. At high densities singlet excitations predominate in equilibrium with atom-molecule de-excitation processes. Possibilities for negative ion generation in a two-chamber tandem system are discussed in which the vibrational excitation occurs in a high power, high electron temperature discharge, kT/sub e/ = 5 eV, and dissociative attachment occurs in a low temperature kT/sub e/ = 1 eV, plasma chamber.
Date: June 28, 1982
Creator: Hiskes, J.R. & Karo, A.M.
System: The UNT Digital Library
Application of Two-time Methods in Stellar Pulsations (open access)

Application of Two-time Methods in Stellar Pulsations

The method of two-time expansions is extended to include the effects of the outer, non-adiabatic layers in stellar pulsation. The evolution of pulsating stellar models can be examined, including the approach to limit cycle behavior. The method is demonstrated by a calculation of the eigenvectors for a ..beta.. Cepheid model. It is argued that the method is promising as a practical tool for treating the approach to limiting oscillations, as well as resonant and multimode behavior.
Date: July 28, 1982
Creator: Pesnell, W. Dean; Regev, Oded & Buchler, J. Robert
System: The UNT Digital Library