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Formation of ions in mass spectrometers by ion-molecule reactions
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Classified Abstracts 266~276 even temperature distribution obtained enhances the formation of a strong and stable iron-tin alloy. (Author, modified) Anon., New Scientist, 9 (218), 19 Jan. 1961, 157. 37
266. Magnetle treatment of hot steel. Anon., New Scientist, 9 (222), 16 Feb. 1961, 408.
appeared on the quartz surface. The silica glass concentration was over 25 per cent, and the heating temperature was above about 1600°C. It is recognized that H~O is discharged from quartz during the process of deformation of the quartz lattice by heat. H20 content in the quartz used in this experiment was probably less than 0.1 per cent. (Author) Y. Moriya, Vacuum, 11 (3), May 1961, 158-172.
37 267. IHigh temperature] coatings for gas turbines. Anon., New Scientist, 10 (239), 15 June 1961, 649.
37 : 30 Vacuum evaporation of Cu, Ag, Sn, Fe and Cr from a TiC heater. See Abstr. No. 231.
37
268. Industrial uses of the platinum metals. A. G. Dowson, New Scientist, 10 (241), 29 June 1961, 796-799. 37 269. Vacuum melting challenged. [A new method for metal purification.] Great Britain. An alternative method is reported for removing volatile impurities from metals; it is suggested that this can replace existing vacuum processes. The method consists of combining an inert gas with an electric arc to produce a hot plasma which impinges on the surface of the molten metal. Extremely high local temperatures are produced and the volatile impurities are carried away. (Author, modified) Anon., New Scientist, 11 (243), 13 July 1961, 94. 37 270. A survey of oxygen steelmaking. D. Garmonsway, New Scientist, 11 (244), 20 July 1961, 153-155. 37 271. Carbon monoxide purge. ~Removal of volatile impurities from molten steel by bubbling.] West Germany. A process for gas bubbling is reported which is an alternative to the purification of steel under vacuum. Carbon monoxide obtained from coke ovens is led into a combustion chamber immediately beneath the vessel of molten steel and burnt in oxygen to form carbon monoxide. The hot gas is then forced into the column of molten steel by passing it through fine bore refractory nozzles in the vessel's base. The impurities are removed with the production of carbon monoxide. Greater efficiency results if halogen compounds are introduced with the gas. (Author, modified) Anon., New Seientist, 11 (245), 27 July 1961, 222. 37 272. Ultra pure tungsten. Great Britain. A special technique is reported by means of which tungsten single crystals with a purity of up to 99.9975 per cent can be produced. The crystals are produced in rods 10in. long and 0.2 in. in diameter and are ductile down to --330°F. Anon., New Scientist, 12 (258), 26 Oct. 1961, 240. 37 273. Vacuum sintering of quartz powder and phase transformation of quartz. Japan. The process of the phase transformation of quartz to silica glass in the range of heating time 10-120 min at the pressure of 10 -~ Torr is as follows : at the heating temperature below about 1700°C, quartz -+ silica glass -+ cristobalite ; at the heating temperature above about 1700°C, quartz --~ silica glass. Quartz transforms to silica glass from the surface of the quartz crystal. Since the surface of the material in general has no definite structure, the transformation temperature of quartz to silica glass ought to be considered not definite. The experiment using --60 mesh quartz powder indicated that sintering was produced by the surface tension of silica glass which
38.
Distillation, Organic Chemistry, Isotopic Gas Analysis
38 274. Mass spectrometric study on the evaporation of volatile components in polyethylene. K. Nakagawa, J. Phys. Soc. Japan, 16 (4), April 1961, 741-745. 38 275. Formation of ions in mass spectrometers by ion-molecule reactions. Great Britain. A wide range o f organic compounds containing oxygen or nitrogen atoms produce prominent peaks at masses greater than those of the parent molecules when introduced into a mass spectrometer. The heights of these peaks have been examined as a function of sample pressure and the number and energy of the bombarding electrons. The most prominent peak formed by ion-molecule reaction in any spectrum is generally that at mass (p + 1), where p represents the mass of the " parent " or molecular ion, and it has been found that the ratio (p + 1)/p reaches a maximum value at electron energies close to the ionization energy of the molecules being studied. In any group of isomers (such as the isomeric C7 ketones) the ratio (p + 1)/p is a minimum for the symmetrical isomer and increases with the degree of asymmetry. The mechanics of the collision process between an ion and a neutral molecule and the lifetime of the complex formed are discussed, restrictions on energy transfer due to symmetry are considered, and the effect of bond orbital character assessed. (Authors) J. H. Beynon, G. R. Lester, A. Saunders and A. E. Williams, Trans. Faraday Soc., 57 (8), Aug. 1961, 1259-1274. 38:16:30:47 The creation and maintenance of clean liquid metal surfaces. See Abstr. No. 166. 38 : 30 Vacuum distillation source image formation by surface sensitization. See Abstr. No. 230. 38:44 Cracking of high vacuum grease and wax vapours on hot platinum. See Abstr. No. 288.
39.
Miscellaneous Applications
39 276. Clean semiconductors. U.S.S.R. A study has been made of the contamination of semiconducting material, such as germanium and silicon, with special reference to the etching reagents used. It has been shown, by using radioactive atoms, that in every square centimetre of surface there are likely to be between 1013-1017 ions, and that the ions of phosphorus, silver and gold, at least, are retained in proportion to their concentrations in the etching reagent. Certain ions are also absorbed from rinsing water. It is suggested that washing semiconductors with complexing reagents and then with organic solvents removes contaminants. (Author, modified) Anon., New Scientist, 12 (257), 19 Oct. 1961, 171.
Classified Abstracts 266~276 even temperature distribution obtained enhances the formation of a strong and stable iron-tin alloy. (Author, modified) Anon., New Scientist, 9 (218), 19 Jan. 1961, 157. 37
266. Magnetle treatment of hot steel. Anon., New Scientist, 9 (222), 16 Feb. 1961, 408.
appeared on the quartz surface. The silica glass concentration was over 25 per cent, and the heating temperature was above about 1600°C. It is recognized that H~O is discharged from quartz during the process of deformation of the quartz lattice by heat. H20 content in the quartz used in this experiment was probably less than 0.1 per cent. (Author) Y. Moriya, Vacuum, 11 (3), May 1961, 158-172.
37 267. IHigh temperature] coatings for gas turbines. Anon., New Scientist, 10 (239), 15 June 1961, 649.
37 : 30 Vacuum evaporation of Cu, Ag, Sn, Fe and Cr from a TiC heater. See Abstr. No. 231.
37
268. Industrial uses of the platinum metals. A. G. Dowson, New Scientist, 10 (241), 29 June 1961, 796-799. 37 269. Vacuum melting challenged. [A new method for metal purification.] Great Britain. An alternative method is reported for removing volatile impurities from metals; it is suggested that this can replace existing vacuum processes. The method consists of combining an inert gas with an electric arc to produce a hot plasma which impinges on the surface of the molten metal. Extremely high local temperatures are produced and the volatile impurities are carried away. (Author, modified) Anon., New Scientist, 11 (243), 13 July 1961, 94. 37 270. A survey of oxygen steelmaking. D. Garmonsway, New Scientist, 11 (244), 20 July 1961, 153-155. 37 271. Carbon monoxide purge. ~Removal of volatile impurities from molten steel by bubbling.] West Germany. A process for gas bubbling is reported which is an alternative to the purification of steel under vacuum. Carbon monoxide obtained from coke ovens is led into a combustion chamber immediately beneath the vessel of molten steel and burnt in oxygen to form carbon monoxide. The hot gas is then forced into the column of molten steel by passing it through fine bore refractory nozzles in the vessel's base. The impurities are removed with the production of carbon monoxide. Greater efficiency results if halogen compounds are introduced with the gas. (Author, modified) Anon., New Seientist, 11 (245), 27 July 1961, 222. 37 272. Ultra pure tungsten. Great Britain. A special technique is reported by means of which tungsten single crystals with a purity of up to 99.9975 per cent can be produced. The crystals are produced in rods 10in. long and 0.2 in. in diameter and are ductile down to --330°F. Anon., New Scientist, 12 (258), 26 Oct. 1961, 240. 37 273. Vacuum sintering of quartz powder and phase transformation of quartz. Japan. The process of the phase transformation of quartz to silica glass in the range of heating time 10-120 min at the pressure of 10 -~ Torr is as follows : at the heating temperature below about 1700°C, quartz -+ silica glass -+ cristobalite ; at the heating temperature above about 1700°C, quartz --~ silica glass. Quartz transforms to silica glass from the surface of the quartz crystal. Since the surface of the material in general has no definite structure, the transformation temperature of quartz to silica glass ought to be considered not definite. The experiment using --60 mesh quartz powder indicated that sintering was produced by the surface tension of silica glass which
38.
Distillation, Organic Chemistry, Isotopic Gas Analysis
38 274. Mass spectrometric study on the evaporation of volatile components in polyethylene. K. Nakagawa, J. Phys. Soc. Japan, 16 (4), April 1961, 741-745. 38 275. Formation of ions in mass spectrometers by ion-molecule reactions. Great Britain. A wide range o f organic compounds containing oxygen or nitrogen atoms produce prominent peaks at masses greater than those of the parent molecules when introduced into a mass spectrometer. The heights of these peaks have been examined as a function of sample pressure and the number and energy of the bombarding electrons. The most prominent peak formed by ion-molecule reaction in any spectrum is generally that at mass (p + 1), where p represents the mass of the " parent " or molecular ion, and it has been found that the ratio (p + 1)/p reaches a maximum value at electron energies close to the ionization energy of the molecules being studied. In any group of isomers (such as the isomeric C7 ketones) the ratio (p + 1)/p is a minimum for the symmetrical isomer and increases with the degree of asymmetry. The mechanics of the collision process between an ion and a neutral molecule and the lifetime of the complex formed are discussed, restrictions on energy transfer due to symmetry are considered, and the effect of bond orbital character assessed. (Authors) J. H. Beynon, G. R. Lester, A. Saunders and A. E. Williams, Trans. Faraday Soc., 57 (8), Aug. 1961, 1259-1274. 38:16:30:47 The creation and maintenance of clean liquid metal surfaces. See Abstr. No. 166. 38 : 30 Vacuum distillation source image formation by surface sensitization. See Abstr. No. 230. 38:44 Cracking of high vacuum grease and wax vapours on hot platinum. See Abstr. No. 288.
39.
Miscellaneous Applications
39 276. Clean semiconductors. U.S.S.R. A study has been made of the contamination of semiconducting material, such as germanium and silicon, with special reference to the etching reagents used. It has been shown, by using radioactive atoms, that in every square centimetre of surface there are likely to be between 1013-1017 ions, and that the ions of phosphorus, silver and gold, at least, are retained in proportion to their concentrations in the etching reagent. Certain ions are also absorbed from rinsing water. It is suggested that washing semiconductors with complexing reagents and then with organic solvents removes contaminants. (Author, modified) Anon., New Scientist, 12 (257), 19 Oct. 1961, 171.