1,779 Matching Results

Search Results

Advanced search parameters have been applied.

Neutrons from High Current Gaseous Discharges

Description: Abstract: "Experiments on the neutrons produced in a high-current pulse discharge in deuterium are described. With 15 kv applied to a straight discharge tube 30 cm in length neutrons are produced at ~1.4 [mu]sec after gas break-down in a pulse 0.1 [mu]sec in length. The yield, 10-7 - 10-8 neutrons per discharge, is quite sensitive to gas purity and discharge tube wall material. The axial asymmetry in neutron energy indicates that the neutrons were produced in reactions whose center of mass moves preferentially towards the cathode. Several mechanisms for the production of these neutrons are discussed."
Date: 1957
Creator: Dunaway, Robert E.
Partner: UNT Libraries Government Documents Department

Relative importance of various sources of defect-producing hydrogen introduced into steel during application of vitreous coatings

Description: "When porcelain enamels or vitreous-type ceramic coatings are applied to ferrous metals, there is believed to be an evolution of hydrogen gas both during and after the firing operation. At elevated temperatures rapid evolution may result in blistering while if hydrogen becomes trapped in the steel during the rapid cooling following the firing operation gas pressures may be generated at the coating-metal interface and flakes of the coating literally blown off the metal. To determine experimentally the relative importance of the principal sources of the hydrogen causing the defects, a procedure was devised in which heavy hydrogen (deuterium) was substituted in turn for regular hydrogen in each of five possible hydrogen-producing operations in the coating process" (p. 269).
Date: July 12, 1951
Creator: Moore, Dwight G.; Mason, Mary A. & Harrison, William N.
Partner: UNT Libraries Government Documents Department

Relative importance of various sources of defect-producing hydrogen introduced into steel during application of vitreous coatings

Description: Report presenting a study in which heavy hydrogen (deuterium) was substituted in turn for regular hydrogen in each of five possible hydrogen-producing operations in the coating process. The gas that evolved when coated steel specimens fishscaled after firing was collected and analyzed with the mass spectrometer.
Date: February 1952
Creator: Moore, Dwight G.; Mason, Mary A. & Harrison, William N.
Partner: UNT Libraries Government Documents Department

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

Distribution Coefficient of D₂O Between Triethylamine and Water

Description: Summary: "Water containing 1.8% D2O was distributed between the two liquid phases formed with triethylamine at 20 and 35 C. The triethylamine was removed from each phase by aseotropic distillation with benzene before analyzing the water by determining its density with a quartz float. The ratios of the concentrations of the D2O in the water layer to that in the amino layer were 1.007 and 1.004 at 20 and 35, respectfully. The differences from unity are about the same as the errors of analysis."
Date: August 31, 1943
Creator: Carlson, H. C.
Partner: UNT Libraries Government Documents Department

Cyclotron Resonance Heating of a Deuterium Plasma

Description: Abstract: "The energy gained by a deuterium plasma, from a three megacycle per second radiofrequency field, was studied experimentally. A static magnetic field, in the form of a "mirror", was used. The coil of an rf resonant circuit, placed at the center of the machine produced a time-varying magnetic field parallel to the static field. This, in turn, induced an electrical field, in an azmuthal direction, which acted on the ions. When this was in synchronism with the cyclotron frequency, the ions could pick up energy. At this resonance the light intensity from the plasma increased markedly. This effect was used as evidence for the transfer of energy to the ions."
Date: October 28, 1957
Creator: Chambers, Edmund S.; Lamb, William A. S. & Kippenhan, Dean O.
Partner: UNT Libraries Government Documents Department

A button source of plasma

Description: From abstract: " This report describes the construction of a plasma source that projects deuterium and titanium ions and eletrons at speeds up to 2 x 10^7 cm/sec."
Date: April 24, 1956
Creator: McIntosh, Virgil G. & Bostick, W. H.
Partner: UNT Libraries Government Documents Department

NMR DOUBLE QUANTUM SPIN DECOUPLING IN SOLIDS

Description: The problem of spin decoupling spin I = 1 nuclei with large quadrupolar splittings {omega}{sub Q} (e.g. deuterium) from dilute S spins via double quantum transitions is dealt with. The normal two spin-1/2 single quantum decoupling problem (I = 1/2, S = 1/2) is first dealt with as a reminder of the coherent averaging approach and to understand the dependence of the S resonance linewidth on the I rf field intensity ({omega}{sub 1}) and resonance offset ({Delta}{omega}). The double quantum problem (I = 1, S = 1/2) is then treated analogously by introducting fictitious spin-1/2 operators for the I double quantum transition. The decoupling condition is found to be very sensitive to the spin-I resonance condition and to go as {approx} 1/4 with the spin I rf field intensity at resonance in the double quantum regime ({omega}{sub 1} << {omega}{sub Q}). Experimental examples on heavy ice, dimethyl-sulfoxide-d{sub 6} and benzene-d{sub 6} are presented verifying the quantitative theoretical predictions. Extensions to higher order multiple quantum effects for spin I > I and for several coupled spin-1/2 nuclei are discussed.
Date: October 1, 1977
Creator: Pines, A.; Vega, S. & Mehring, M.
Partner: UNT Libraries Government Documents Department

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

The Angular Distribution and Total Flux of Neutrons Obtained from the Deuterium-Tritium Reaction

Description: Mono-energetic neutrons have been produced with the low-voltage Cockroft-Walton accelerator at North Texas State College using two different reactions. It is the purpose of this paper to report the angular distribution and total flux of the neutrons obtained from the T(D,n) reaction.
Date: 1956
Creator: Duggan, Jerome L.
Partner: UNT Libraries

Equation of State measurements of hydrogen isotopes on Nova

Description: High intensity lasers can be used to perform measurements of materials at extremely high pressures if certain experimental issues can be overcome. We have addressed those issues and used the Nova laser to shock-compress liquid deuterium and obtain measurements of density and pressure on the principal Hugoniot at pressures from 300 kbar to more than 2 Mbar. The data are compared with a number of equation of state models. The data indicate that the effect of molecular dissociation of the deuterium into a monatomic phase may have a significant impact on the equation of state near 1 Mbar.
Date: November 1, 1997
Creator: Collins, G. W., LLNL
Partner: UNT Libraries Government Documents Department

Report on the deuterium retention in CVD coated W on SiC in support of the Ultramet Company’s Small Business Innovation Research (SBIR) project: SOW DE-FG02-07ER84941

Description: A tungsten (W) coated (0.0005-inch thickness) silicon carbide (SiC) (1.0-inch diameter and 0.19-inch thickness) sample was exposed to a divertor relevant high-flux (~1022 m-2s-1) deuterium plasma at 200 and 400°C in the Idaho National Laboratory’s (INL’s) Tritium Plasma Experiment (TPE), and the total deuterium retention was subsequently measured via the thermal desorption spectroscopy (TDS) method. The deuterium retentions were 6.4x1019 m-2 and 1.7x1020 m-2, for 200 and 400°C exposure, respectively. The Tritium Migration Analysis Program (TMAP) was used to analyze the measured TDS spectrum to investigate the deuterium behavior in the W coated SiC, and the results indicated that most of the deuterium was trapped in the W coated layer even at 400°C. This thin W layer (0.0005-inch ~ 13µm thickness) prevented deuterium ions from bombarding directly into the SiC substrate, minimizing erosion of SiC and damage creation via ion bombardment. The shift in the D desorption peak in the TDS spectra from 200 C to 400°C can be attributed to D migration to the bulk material. This unexpectedly low deuterium retention and short migration might be due to the porous nature of the tungsten coating, which can decrease the solution concentration of deuterium atoms.
Date: June 1, 2012
Creator: Shimada, Masashi
Partner: UNT Libraries Government Documents Department

Hydrogen Isotope Exchange Properties of Porous Solids Containing Hydrogen

Description: Porous solids such as activated alumina, silica and molecular sieves generally contain significant amounts of hydrogen atoms in the form of H2O or OH even at high temperature and low humidity environment. A significant amount of this hydrogen is available for reversible isotopic exchange. This exchange reaction is slow under normal conditions and does not render itself to practical applications. But if the exchange kinetics is improved this reaction has the potential to be used for tritium removal from gas streams or for hydrogen isotopic separation.The use of catalysts to improve the exchange kinetics between hydrogen isotope in the gas phase and that in the solid phase was investigated. Granules of alumina, silica and molecular sieve were coated with platinum or palladium as the catalyst. The granules were packed in a 2-cm diameter column for isotope exchange tests. Gas streams containing different concentrations of deuterium in nitrogen or argon were fed through the protium saturated column. Isotope concentration in column effluent was monitored to generate isotope break-through curves. The curves were analyzed to produce information on the kinetics and capacity of the material. The results showed that all materials tested provided some extent of isotope exchange but some were superior both in kinetics and capacity. This paper will present the test results.
Date: August 18, 2004
Creator: HEUNG, LEUNGK.
Partner: UNT Libraries Government Documents Department

COMPARISON OF AIR AND DEUTERIUM ON PINCH WELD BOND APPEARANCE

Description: The effect that air and deuterium internal atmospheres have on the pinch weld bond quality was evaluated by conducting a scoping study using type 304L stainless steel LF-7 test stems that were fabricated for an associated study. Welds were made under cool, yet nominal conditions to exacerbate the influence of the atmosphere. The bond quality of the welds was directly related to the internal atmosphere with the air atmosphere welds being of lower quality than the deuterium atmosphere welds for nominally identical welding conditions.
Date: October 11, 2005
Creator: Korinko, P
Partner: UNT Libraries Government Documents Department