Classified abstracts 595--602

.charge carriers in the film. Thickness measurements can be carried out either on oblique sections after staining or by interference methods. The electrical resistance is measured with the help of either 4 or 5 probes whilst concentration and mobility of charge carriers are either determined on films separated from the substrate or two-layer structures are used. These experiments involve high frequency measurements of the impedance and capacitance of the films. The last section of the review deals with film defects, X-ray analysis and optical (microscopical) methods. Iu A Kontsecoi, Pribory i Tekh Eksper, (1), 1965, 5-I6, (in Russian)

33 : 56 595. Very-high-current density electron beams. (USA) A beam from an electron gun is first made to converge in the usual way by electrostatic fields to a compression ratio of 300:1. It then enters the field of a short magnetic lens causing further compression to a total of 1350:1. The current density achieved is 2500 A cm -2 and the beam diameter 0.013 in. L Kikushima and C C Johnson, Proc 1EEE, 52, Jan 1964, 12.

33 : 38 596. Chemical synthesis with ion beams. (USA) A method of chemical synthesis by gas phase ion-molecule reac- tions analogous to known liquid phase reactions is described. The

synthesis of nitrobenzene by the reaction of NO2 + and benzene is reported. The interaction of a beam of NO~ + ions with max imum energies of 1 eV with gaseous benzene gave nitrobenzene in high yield. A 1-ma. ion current consisting of 99 per cent NO~ + was formed by electron impact with nitrogen dioxide in a concentric dual-anode magnetron. (Author) S Singer et al, J Phys Chem, 69, March 1965, 799-803.

33 597. The production of molecular beams in the mass spectrometer. (USA) B P Burtt and J M HeNs, J Phys Chem, 68, Dee 1964, 3905-3907.

33 : 4l 598. Analysis of the ionization of caesium in tungsten capillaries. ( USA ) A T Forrester, J Chem Phys, 42 (3), Feb 1965, 972-980.

34. H i g h a l t i t u d e a n d s p a c e t e c h n o l o g y 34

599. Space chamber tests on satellites. (Germany) In order to ensure proper functioning of a satellite, all individual components and subsequently the complete satellite should be tested under environmental conditions. Whilst tests of components present no undue difficulties, an exact reproduction of environ- mental conditions for the complete satellite is generally not possible. The author estimates the degree of uncertainty introduced by these necessary approximations, especially as regards temperature condi- tions. The main difficulty concerns the establishment of optically black conditions inside the test chamber and introducing simulated solar and earth radiations of the correct quality. Possible solutions based mainly on American practice are reviewed. M Wutz, Vakuum Techn, 14 (2), March 1965, 33-40, (in German).

37. Metallurgy, inorganic chemistry, analytical chemistry

37 A master set of ion sources for mass spectrometers. See abstract number 546.

37 Novel ion counter of maximum sensititivy and unlimited life as aid in high vacuum techniques. See abstract number 571.

37 Electroplated coatings. See abstract number 589.

37 -600. The chemi-luminescent reaction of oxygen atoms with sulphur monoxide at low pressures. (USA) The reaction of oxygen atoms with sulphur monoxide results in a visible blue emission, extending into the ultraviolet. The reaction was studied in the low pressure region up to a total pressure of 20 where the emission was found to be due to the simple two-body reaction, SO + O -+ SO2 + hv, analogous to the two-body reac- tion of nitric oxide and oxygen atoms. The rate coefficient for this reaction was estimated as 7 × 10 -1~ cm3/molecule sec. The SO was produced by reaction with O atoms via COS + O -+ CO +

SO. This reaction could also be used under certain conditions to titrate the oxygen atoms to obtain a quantitative measure of the oxygen a tom concentration. (Author) T R Rolfes et al, J Phys Chem, 69, March 1965, 849-853.

38. Distillation, organic chemistry, isotopic gas analysis

38 601. Specific rearrangements in the mass spectra of short chain esters. (USA) D R Black et al, JPhys Chem, 68, May 1964, 1237-1240.

38 602. Reaction of tritium atoms with films of solid ethylene. Dispro- portionation and combination of ethyl radicals at 63°K. (USA) Films of solid ethylene at 63°K were bombarded with trit ium atoms. Products (ethylene, ethane, and butane) of disproportiona- tion and combination reactions of ethyl radicals were observed. Conditions were selected under which the only apparent reactions of ethyl radicals were disproportionation and combination. Under these conditions, no contribution from tritium a tom addition to ethyl or product ethylene was evident. A disproportionation to combination ratio (k~/kc) of 0.77 ± 0.03 was observed for C~H4T+ C2H~T, and a ratio of 0.83 =i= 0.04 was observed for C2H4T + C2H~. Two methods of calculating the trit ium isotope effect in the disproportionation of ethyl radicals gave k~/kT = 1.7 ~ 0.7 and k~/kT = 2.3 ___ 0.5. These small primary kinetic isotope effects are consistent with the mechanism discussed by Bradley and Rabinovitch that involves a "loose" transition state for dispropor- tionation in which little or no binding occurs. (Author) K W Watkins and H C Moser, J Phys Chem, 69, March 1965, 1040 1044.

38 Chemical synthesis with ion beams. See abstract number 596.

IV. Materials and techniques used in vacuum technology

40. Gases and vapours 40

Fluctuation of the hydrogen partial pressure in a receiver evacuated by means of an oil vapour pump. See abstract number 515.

40 Approximate formulae for the viscosity and thermal conductivity of gas mixtures. See abstract number 519.

40 Gaseous diffusion. The systems He-Ar, Ar-Xe and He-Xe. See abstract number 535.

40 Excitation of methane, ethane, ethylene, propylene, acetylene, propyne and 1-butyne by low energy electron beams. See abstract number 551.

40 Ionization and excitation of argon with alpha particles. See abstract number 552.

40 Reactions of 12-135 eV H2 + ions with Ar. See abstract number 553.

40 Relative intensities of Lyman-Birge-Hopfield bands in electron impact spectrum of nitrogen. See abstract number 554.

4O Conversion of ion types in nitrogen. See abstract number 556.

40 Study of collision effects between the constituents of a mixture of helium and nitrogen gases when excited by a 10 keV electron beam. See abstract number 557.

4O Hydrogen and helium bubble chambers. See abstract number 610.

41. Metals and alloys

Thermal desorption of Sr from W. See abstract number 536. 41

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