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X-ray detector calibrations in the 280-eV to 100-keV energy range (open access)

X-ray detector calibrations in the 280-eV to 100-keV energy range

The absolute sensitivity for several different types of radiation detectors has been measured using x-rays in the energy range of 280 eV to 100 keV. The photons in this energy range are produced using three separate x-ray-generating facilities. The detectors include a silicon semiconductor, two photoelectric diode detectors employing aluminum and gold photocathodes, and three detectors incorporating plastic scintillators and photodiodes. The plastic scintillators were MEL-150C, Pilot B, and NE102.
Date: April 21, 1976
Creator: Gaines, J. L.; Kuckuck, R. W. & Ernst, R. D.
System: The UNT Digital Library
Picosecond x-ray spectral studies (open access)

Picosecond x-ray spectral studies

Temporally and spectrally resolved x-ray emission is an important diagnostic tool for the study of target heating and compression induced by sub-nanosecond laser pulses. The use of the Livermore 15 psec x-ray streak camera to record x-ray emissions in the 1-10 keV range is described. In particular, significant progress is reported during the past year in defining the camera as a quantitative diagnostic instrument, and its implementation for multi-channel, time resolved K-edge filter measurements. Data will be presented which describe x-ray emission from a laser imploded 87 ..mu..m diameter glass shell. Channels centered at 2.6, 4.0 and 5.3 keV provide temporal information which is related to the absorption and compression phases of laser heating. The relative spectral content is found to be in agreement with standard, time integrated measurements.
Date: July 21, 1976
Creator: Attwood, D. T. & Coleman, L. W.
System: The UNT Digital Library
Plasma flows in the conduction region of a spherical laser target (open access)

Plasma flows in the conduction region of a spherical laser target

Analytic solutions are dervied for plasma flows in a spherical laser target, emphasizing the region which lies between the ablation surface and the critical density surface. Electron thermal conductivity dominates the heat transport in this zone. Both classical electron thermal conduction and flux-limited conduction are treated in which the finite electron thermal velocity provides an upper bound to the heat flux. These analytic solutions are compared with computational results from 1-D hydrodynamics calculations. Finally, the implications of these solutions for growth rates of plasma instabilities in the conduction region are considered.
Date: October 21, 1976
Creator: Max, C. E.; McKee, C. F. & Mead, W. C.
System: The UNT Digital Library
Theoretical tool movement required to diamond turn an off-axis paraboloid on axis (open access)

Theoretical tool movement required to diamond turn an off-axis paraboloid on axis

Current techniques for manufacturing off-axis paraboloids are both expensive and insufficiently accurate. An alternative method, turning the workpiece about its axis on a diamond-turning machine, is presented, and the equations describing the necessary tool movement are derived. A discussion of a particular case suggests that the proposed technique is feasible.
Date: July 21, 1976
Creator: Thompson, D. C.
System: The UNT Digital Library
Fast-neutron detector for use as a criticality monitor (open access)

Fast-neutron detector for use as a criticality monitor

To increase the reliability of the criticality monitoring system in a diagnostic chemistry area and to reduce the number of false alarms, a new monitoring system was built using a fast-neutron detector. This paper outlines the design requirements, describes the plastic scintillation detector system as it was built, and reports on the results of several months of operation. The new monitor has proven much more useful than the gamma-detector system it replaced.
Date: September 21, 1976
Creator: Friesen, R. D.
System: The UNT Digital Library
Fission fragment simulation of fusion neutron radiation effects on bulk mechanical properties (open access)

Fission fragment simulation of fusion neutron radiation effects on bulk mechanical properties

This research demonstrates the feasibility of using homogeneously-generated fission fragments to simulate high-fluence fusion neutron damage in niobium tensile specimens. This technique makes it possible to measure radiation effects on bulk mechanical properties at high damage states, using conveniently short irradiation times. The primary knock-on spectrum for a fusion reactor is very similar to that produced by fission fragments, and nearly the same ratio of gas atoms to displaced atoms is produced in niobium. The damage from fission fragments is compared to that from fusion neutrons and fission reactor neutrons in terms of experimentally measured yield strength increase, transmission electron microscopy (TEM) observations, and calculated damage energies.
Date: September 21, 1976
Creator: Van Konynenburg, R. A.; Mitchell, J. B.; Guinan, M. W.; Stuart, R. N. & Borg, R. J.
System: The UNT Digital Library
Hydrogen--deuterium exchange in water vapor: the mass spectrometric sensitivities and the equilibrium constant (open access)

Hydrogen--deuterium exchange in water vapor: the mass spectrometric sensitivities and the equilibrium constant

The equilibrium constant, K/sub HDO/, for the reaction H/sub 2/O + D/sub 2/O = 2HDO can be expressed as an intensity ratio, I, measured mass spectrometrically, times a sensitivity ratio, S, measured in mass spectrometric calibration experiments. The latter is difficult to measure and previously was assumed to be unity. The 2.4 percent discrepancy between K's from theoretical calculations and direct mass spectrometric measurements might be explained by another value of S. An indirect measurement of S using a pulsed-molecular beam quadrupole mass filter that has a unique three-chamber, three-leak gas inlet system is reported. The results show the sensitivities are probably equal and therefore S = 1. Systematic errors were found in the procedure, however, which precluded an unambiguous test of the theory.
Date: April 21, 1976
Creator: Pyper, J. W.; Dupzyk, R. J.; Friesen, R. D.; Bernasek, S. L.; May, C. A.; Echeverria, A. W. et al.
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 the blowing agent decomposes to blow the drop into a balloon. An analysis is made of the heat flow process and photographs of the resulting glass balloons are presented.
Date: October 21, 1976
Creator: Hendricks, C. D. & Dressler, J. L.
System: The UNT Digital Library
Ultraviolet probing of laser produced plasmas with picosecond pulses (open access)

Ultraviolet probing of laser produced plasmas with picosecond pulses

Technical photography, through such means as interferometry, Faraday rotation, and simple shadowgraphs, can provide significant data for understanding the absorption and transport of energy within laser produced plasmas. For plasmas produced by intense, sub-nanosecond Nd laser pulses, one is required to study electron densities in the 10/sup 20/ to 10/sup 21/ e/cc range, with density contour velocities of 10/sup 6/ to 10/sup 7/ cm/sec, and axial scale lengths of 1-20 ..mu..m. The relationship between these plasma parameters and the requisite photographic system is described. It is concluded that the system requires a probe wavelength in the middle ultraviolet, a pulse duration in the 10-100 picosecond regime, and large numerical aperture optics corrected for spherical aberrations. Results obtained at 2660 A with holographic microinterferometry, Faraday rotation, and shadowgraphs are presented.
Date: July 21, 1976
Creator: Attwood, D. T. & Coleman, L. W.
System: The UNT Digital Library
Design of a new low momentum kaon beam for the AGS (open access)

Design of a new low momentum kaon beam for the AGS

The low momentum beam described is to be a unique source of antiprotons as well as kaons. The discussion covers (1) choice of production angle; (2) secondary beams; (3) the use of sector dipole magnets for minimizing aberrations; (4) beam bending magnets; (5) beam separators; and (6) beam acceptance. (PMA)
Date: June 21, 1976
Creator: Lazarus, D M
System: The UNT Digital Library
Simplified scheme or radioactive plume calculations (open access)

Simplified scheme or radioactive plume calculations

A simplified mathematical scheme to estimate external whole-body $gamma$ radiation exposure rates from gaseous radioactive plumes was developed for the Rio Blanco Gas Field Nuclear Stimulation Experiment. The method enables one to calculate swiftly, in the field, downwind exposure rates knowing the meteorological conditions and $gamma$ radiation exposure rates measured by detectors positioned near the plume source. The method is straightforward and easy to use under field conditions without the help of mini-computers. It is applicable to a wide range of radioactive plume situations. It should be noted that the Rio Blanco experiment was detonated on May 17, 1973, and no seep or release of radioactive material occurred. (auth)
Date: November 21, 1976
Creator: Gibson, T. A. & Montan, D. N.
System: The UNT Digital Library