Abstract: A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photolysis, photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photolysis, photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium.

Abstract: The novel compound plutonium pentafluoride may be prepared by the photodissociation of gaseous plutonium hexafluoride. It is a white solid of low vapor pressure, which consists predominantly of a face-centered cubic structure with a.sub.o =4.2709.+-.0.0005 .ANG..

Abstract: A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Abstract: Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO.sub.2 laser light may be used to highly enrich .sup.34 S in natural SF.sub.6 and .sup.11 B in natural BCl.sub.3.

Abstract: Very smooth polymeric coatings or films graded in atomic number and density an readily be formed by first preparing the coating or film from the desired monomeric material and then contacting it with a fluid containing a metal or a mixture of metals for a time sufficient for such metal or metals to sorb and diffuse into the coating or film. Metal resinate solutions are particularly advantageous for this purpose. A metallic coating can in turn be produced on the metal-loaded film or coating by exposing it to a low pressure plasma of air, oxygen, or nitrous oxide. The process permits a metallic coating to be formed on a heat sensitive substrate without the use of elevated temperatures.

Abstract: A method of boron isotope enrichment involving the isotope preferential photolysis of (2-chloroethenyl)dichloroborane as the feed material. The photolysis can readily be achieved with CO.sub.2 laser radiation and using fluences significantly below those required to dissociate BCl.sub.3.

Abstract: The thermostatically controlled valve is of a type wherein the flow of fluid is increased when the temperature of the fluid is in a low to medium range and decreased as the temperature of the fluid exceeds a desired range. In a preferred embodiment, it makes use of a poppet valve assembly. It is particularly useful to control the temperature at which vaporization occurs in a liquid propane vaporizer utilized in the fuel system of an internal combustion engine.

Abstract: A method of growing single crystals of beta SiC from solution using molten lithium as a solvent for polycrystalline SiC feed material. Reasonable growth rates are accomplished at temperatures in the range of about 1330.degree. C. to about 1500.degree. C.

Abstract: By fluorinating diamond grit, the grit may be readily bonded into a fluorocarbon resin matrix. The matrix is formed by simple hot pressing techniques. Diamond grinding wheels may advantageously be manufactured using such a matrix. Teflon fluorocarbon resins are particularly well suited for using in forming the matrix.

Abstract: A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Abstract: A low voltage, electrically actuated, nonprimary explosive detonator is disclosed wherein said detonation is achieved by means of an explosive train in which a deflagration-to-detonation transition is made to occur. The explosive train is confined within a cylindrical body and positioned adjacent to low voltage ignition means have electrical leads extending outwardly from the cylindrical confining body. Application of a low voltage current to the electrical leads ignites a self-sustained deflagration in a donor portion of the explosive train which then is made to undergo a transition to detonation further down the train.

Abstract: In XeBr lasers which make use of HBr as the source of bromine, it has been found that the working life of the laser is limited because of dissociation of the HBr in the lasing region to form H.sub.2 and Br.sub.2. Accordingly, apparatus is disclosed for substantially improving the working time of the XeBr laser wherein means are provided for recombining H.sub.2 and Br.sub.2 into HBr and for continuously circulating the gaseous working medium from the lasing region through the recombination region.

Abstract: Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

Abstract: A method of initiating a rapid pH change in a solution by irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

Abstract: Micro concentrations of .sup.68 Ga in secular equilibrium with .sup.68 Ge in strong aqueous HCl solution may readily be separated in ionic form from the .sup.68 Ge for biomedical use by evaporating the solution to dryness and then leaching the .sup.68 Ga from the container walls with dilute aqueous solutions of HCl or NaCl. The chloro-germanide produced during the evaporation may be quantitatively recovered to be used again as a source of .sup.68 Ga. If the solution is distilled to remove any oxidizing agents which may be present as impurities, the separation factor may easily exceed 10.sup.5. The separation is easily completed and the .sup.68 Ga made available in ionic form in 30 minutes or less.

Abstract: The ammonium salt of 3,5-dinitro-1,2,4-triazole has utility as a chemical explosive. In accordance with the present invention, it may readily be produced by solvent extraction using high-molecular weight, water-insoluble amines followed by amination with anhydrous ammonia gas. The aqueous reaction mixture produced in the synthesis of the parent compound, 3,5-dinitro-1,2,4-triazole, is quite suitable--and indeed is preferred--for use as the feed material in the process of the invention.

Abstract: Hydrogen isotope separation is achieved by either (a) dissolving a hydrogen-bearing feedstock compound in a liquid solvent, or (b) liquefying a hydrogen-bearing feedstock compound, the liquid phase thus resulting being kept at a temperature at which spectral features of the feedstock relating to a particular hydrogen isotope are resolved, i.e., a clear-cut isotope shift is delineated, irradiating the liquid phase with monochromatic radiation of a wavelength which at least preferentially excites those molecules of the feedstock containing a first hydrogen isotope, inducing photochemical reaction in the excited molecules, and separating the reaction product containing the first isotope from the liquid phase.

Abstract: Bulk coatings of Nb.sub.3 Ge with high superconducting transition temperatures bonded to metallic substrates and a chemical vapor deposition method for producing such coatings on metallic substrates are disclosed. In accordance with the method, a Nb.sub.3 Ge coating having a transition temperature in excess of 21.5 K may be tightly bonded to a copper substrate.

Abstract: An optical parametric oscillator is disclosed in which the resonant radiation is separated from the pump and output radiation so that it can be manipulated without interfering with them. Thus, for example, very narrow band output may readily be achieved by passing the resonant radiation through a line narrowing device which does not in itself interfere with either the pump radiation or the output radiation.

Abstract: By use of an appropriate thermoplastic rubber as the binder, the thermal stability and thermal stress characteristics of plastic-bonded explosives may be greatly improved. In particular, an HMX-based explosive composition using an oil-extended styrene-ethylenebutylene-styrene block copolymer as the binder exhibits high explosive energy and thermal stability and good handling safety and physical properties.