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An Automated Supernova Search and the Design Strategy

Description: The design considerations for an automated supernova search are reviewed. If supernova are to be found a week after explosion well before light maximum of both Types I and II, and if a rate of finding of 52 per year is justified, then one needs to keep roughly 5000 galaxies under surveillance out of a full set of 15,000 galaxies at approx. =50 Mpc distance. For detection at 1% of Type I maximum light requires a 30-inch telescope, 10 photoelectrons per pixel threshold, a 128 x 128 pixel photodetector operating with a 3-second integration time, and 2 seconds to slew and settle approx. =1/sup 0/. A system designed to perform this function in real-time is described. 7 refs.
Date: January 1, 1987
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Galactic Origin of Cosmic Rays I

Description: The theoretical basis for the supernova envelope shock origin of cosmic rays is reviewed. The theoretical explanation of the SN Type I light curve requires the ejection of a relativistic mass fraction. The criterion of the adiabatic decelleration by Alfven wave trapping neither applies in theory, when ..beta.. > 1, or practice, the Starfish high altitude nuclear explosion experiment. Arguments of delayed acceleration due to K-capture are not applicable to SN ejecta because a period of prompt recombination exists before subsequent stripping in propagation.
Date: January 1, 1981
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Galactic Origin of Cosmic Rays II

Description: The CR acceleration due to shocks in the ISM depends upon multiple crossings approx. = c/3 v/sub Alfven/ approx. = 10/sup 4/ per e-fold energy gain. The up-stream scattering required to produce this barrier is Alfven wave turbulence. When the ratio (CR pressure)/(B/sup 2//8..pi..) identical = ..beta.. > 1, the streaming velocity theoretically and observationally becomes >> v/sub Alfven/ and, hence, no effective up-stream barrier is likely to exist. If all ISM shock acceleration is limited to ..beta.. approx. << 1 and the average galactic CR conditions is ..beta.. approx. = 1, then shocks in the ISM are unlikely to supply the necessary acceleration. This is particularly so for high energy CR's accelerated early in the remnant history where ..beta.. must be large and the number of e-folds required are large. High energy CR's can be produced by the shock breaking out of the envelope into the magnetosphere of the SN star for E approx. > 10/sup 13/ to 10/sup 14/ eV. It is usually assumed that the energy dependent escape from the Galaxy E approx. > 10/sup 15/ eV produces a steeper spectrum from 10/sup 15/ to 10/sup 18/ eV. Above this energy SN's in all galaxies fill the meta galaxy with CR's with a flatter slope. Conversely, an external source that attempts to fill the Galaxy from the outside must have a still steeper spectrum ..delta..GAMMA approx. = -.75 to penetrate the diffusive barrier of our galaxy yet maintain the observed slope. This is unlikely since the energy density at 10/sup 15/ eV in the meta galaxy would be between 10/sup -1/ to 10/sup -2/ of CR's in this galaxy or of the order of 10/sup 3/ of the energy density of particles and fields in the IGM.
Date: January 1, 1981
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Ground Based Automated Telescope

Description: Recommendation that a ground-based automated telescope of the 2-meter class be built for remote multiuser use as a natural facility. Experience dictates that a primary consideration is a time shared multitasking operating system with virtual memory overlayed with a real time priority interrupt. The primary user facility is a remote terminal networked to the single computer. Many users must have simultaneous time shared access to the computer for program development. The telescope should be rapid slewing, and hence a light weight construction. Automation allows for the closed loop pointing error correction independent of extreme accuracy of the mount.
Date: January 1, 1980
Creator: Colgate, Stirling A. & Thompson, WIlliam
Partner: UNT Libraries Government Documents Department
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Supernova Explosions: The Role of a Rayleigh-Taylor Instability

Description: A two dimensional hydrodynamic study indicates that convectively unstable gradients which develop during core collapse and bounce give rise to large scale core overturn. It is also shown that the concomitant release of neutrinos can deposit large amounts of energy and momentum in the infalling envelope and give rise to a powerful supernova explosion.
Date: January 1, 1980
Creator: Buchler, J. Robert; Livio, Mario & Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Light Curve of Type I Supernovae

Description: Calculations of the intermediate and late time luminosity of type I supernovae based on 100% efficiency for optical emission of energy deposited by the Ni/sup 56/ decay chain give good agreement with observations provided M/sub ej/ v/sup -2/ = (2.2 +- 0.5) x 10/sup 17/ M. s/sup 2/ cm/sup -2/ where M/sub ej/ is the ejected mass an v is the expansion velocity. Account must be taken of the escape of both gamma rays and positrons. These two escape processes as well as the early luminosity peak as calculated by Colgate and McKee are all consistent with the same value of M/sub ej//v/sup 2/.
Date: January 1, 1980
Creator: Colgate, Stirling A.; Petschek, A. G. & Kriese, John T.
Partner: UNT Libraries Government Documents Department
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Regenerator optimization for Stirling cycle refrigeration

Description: A cryogenic regenerator for a Stirling cycle is designed using a fractional loss or entropy gain as the criterion of performance. The gas losses are treated separately from heat storage medium losses. For the optimum channel flow nonturbulent design, the maximization of heat transfer from the gas to the wall and the minimization of entropy production by friction leads to a gas flow velocity criterion of sound speed times loss fraction. This velocity with a given frequency leads to a Stirling cycle dead volume ratio and consequently a channel of specified length and width. The thermal properties of the channel wall must then accommodate this cyclic heat flow without substantially increasing the loss fraction. It is found that stainless steel or plastics are adequate for 30 to 300 K, but that lower temperature stages 4 to 30 K require either a special lead alloy of moderate conductivity or a segmented anisotropic construction of alternate highly conducting lead layers and alternate insulating glass or epoxy fiber glass spacers. An overall efficiency of {congruent} 50% of Carnot is predicted at a frequency of 30 Hz and a pressure of one atmosphere.
Date: August 1, 1993
Creator: Colgate, Stirling A. & Petschek, Albert G.
Partner: UNT Libraries Government Documents Department
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A Description of a Shock Wave in Free Particle Hydrodynamics with Internal Magnetic Fields

Description: Abstract: "The structure of an extremely strong magnetohydrodynamic shock is discussed in the limit of no particle collisions. It is tentatively concluded that the shock transition takes place through the mechanism of a strong electric field produced by charge separation. The pressure in the shocked plasma is due primarily to a very high electron temperature. The ions, on the other hand, undergo an irreversible temperature change of only 3."
Date: February 19, 1957
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Initial Conditions for the Dynamic Pinch

Description: Abstract: "The experimental formation of the dynamic pinch has been an art based upon available electrical condensers, available glass and quartz tubing and an empirically determined gas pressure range. This report attempts to correlate some of this empirical information with the processes of ionization, insulator wall heating, magnetic field penetration, and shock hydrodynamics."
Date: March 1957
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Liquid-Sodium Instability Experiment : Part I

Description: Abstract: "A magnetohydrodynamic model of a plasma-magnetic field instability, using liquid sodium, has been observed. The growth rate and wave length of the Taylor-type acceleration instability was observed to be in agreement with the theory of Kruskal and Schwarzschild."
Date: September 30, 1955
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Liquid-Sodium Instability Experiment : Part II

Description: Abstract: "A magnetohydrodynamic model of plasma-magnetic field instabilities, using liquid sodium, has been observed. The growth of flutes in the mirror geometry was observed for the case of [beta] = NKT/H²/8w = 1."
Date: September 30, 1955
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Neutron Production in the Pinch Due to Instability Breakup

Description: Abstract: "The neutrons from the linear pinch in Berkeley have been shown to originate from deuteron collisions with a large net center-of-mass velocity in one direction along the axis of the pinch tube. The interpretation of this result is that the neutron production associated with the pinch is non-thermonuclear in origin. The object of this paper is to review the experimental evidence and discuss a possible source of the neutron production."
Date: May 12, 1956
Creator: Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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Small-Scale Instabilites of the Pinch and a Suggested Remedy: The Levitron

Description: Report discussing "experimental results on the classical stabilized pinch," "the usefulness of the Levitron in Stellarator-type operation," and "practical details of the levitation process." A configuration is presented which involves a "toroidal pinch tube inside which a rigid toroidal conductor is levitated by means of an induced magnetic field." Additionally, "an alternative scheme is considered, where the toroidal core is suspended from current-carrying wires, but this approach does not appear promising."
Date: September 1958
Creator: Colgate, Stirling A. & Furth, H. P.
Partner: UNT Libraries Government Documents Department
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Large Toroidal Stabilized Pinch Proposal

Description: This report focuses on the study of the stabilized pinch program made to increase the plasma temperature and improve the plasma conductivity and containment. One method proposed is the usage of a large toroidal stabilized pinch, which is described here.
Date: January 29, 1958
Creator: Colgate, Stirling A. & Furth, H. P.
Partner: UNT Libraries Government Documents Department
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Collapse : The Shock Heating of a Plasma

Description: There have been numerous independent suggestions to use high speed shocks to heat deuterium gas to thermonuclear temperature (E. Teller, R.R. Wilson, H. Grad, W. Marshall)², and extensive experimental work in this field is being carried on by, e.g., Kolb³, and S. Janes⁴. Our own work in this field has been directed towards a fundamental understanding of the strong shock process in the limit of no particle collision, to find out if within this limit the ion heating following the passage of the shock is large enough to give rise to a thermonuclear reaction.
Date: March 7, 1958
Creator: Colgate, Stirling A. & Wright, R. E.
Partner: UNT Libraries Government Documents Department
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Boundary-layer formation in the pinch

Description: From abstract: "A study is made of various processes that occur prior to the pinch effect when an electric field is applied to a deuterium gas. The variables of the problem are percentage of ionization, the electron and ion temperatures, the resistivity of the gas, and the current density."
Date: August 10, 1959
Creator: Killeen, John; Gibson, Gordon & Colgate, Stirling A.
Partner: UNT Libraries Government Documents Department
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The Hard-Core Pinch. I

Description: This report analyzes a linear, hard-core pinch tube built to examine tubes afflicted by small-scale instabilities evident from many observations.
Date: July 31, 1959
Creator: Birdsall, D. H.; Colgate, Stirling A. & Furth, Harold P.
Partner: UNT Libraries Government Documents Department
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The Hard-Core Pinch. II

Description: This report describes a toroidal version of the hard-core pinch and the additional information it can obtain to what the analogous linear pinch can get.
Date: July 31, 1959
Creator: Birdsall, D. H.; Colgate, Stirling A. & Furth, Harold P.
Partner: UNT Libraries Government Documents Department
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