Negative ions in sulphur dioxide

Classified abstracts 545-559 recombination rate in Xe and Ar stationary discharge plasma is measured in dependence on gas temperature. (USSR) K P Novikova, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,35. 18 545. Kinetic study of the ultraviolet continuum of argon. (Czechoslovakia) The evolution with time of the number of Ar excited states at irradiation of argon at pressures ranging from 100 to 700 torr by alphaparticles from Amz41 and leading to the emission at 210 nm maximum of the continuous emission, is measured. (France) A Birot et al, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,36. 18 546. Decay of the ultraviolet continuum radiation in rare gases. (Czechoslovakia) The temperature dependence of the decay of the ultraviolet continuum in the afterglow of a pulsed direct discharge in krypton and argon is investigated. A cylindrical discharge tube was provided with a LiF window. (Belgium) J Lenaerts and W Wieme, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973, 37. 18 547. Study of the decay of a pulsed photoionized plasma in an electronegative gas. (Czechoslovakia) Using a Langmuir probe, evolution of charge density has been observed in an electronegative gas plasma afterglow in the pressure range of 1.5 x 10e2 to 4 torr. The plasma was created by photoionizing radiation emitted by a laser plasma produced at ruby laser beam irradiation of lead target in vacuum. (France) J Bruneteau and E Fabre, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,40. 18 548, Influence of electron distribution function on dissociation in glow discharge. (Czechoslovakia) Using a spectroscopical method, it is experimentally shown that the number of effective electrons capable of chemical reactions in glow discharge plasma decreases with the concentration of the gases capable of a chemical reaction. The experiments were performed in Ar and Nz at pressures 2 and 4.5 torr. J Preis, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,42. 18 549. Spectroscopic diagnostic of a nitrogen reflex discharge. (Czechoslovakia) Using the spectroscopic diagnostics, the axial distribution of the relative intensity of the N2+ band and the radial distribution of Nz and NZ+ vibrational temperatures are measured in a reflex discharge in nitrogen at pressures ranging from 10m4 to 10mz torr. The reflex discharge was excited in a stainless steel tube 1 m long and with 10 cm diameter and immersed in magnetic field of 300 to 10,000 Gauss. (France) A Vicherat and S C Georges, Proc of 11th Znternat Conf on Phenom in toniz Gases, Prague 1973, 45. 18 550. The rate coefficient for the quenching reaction Na* + H, --f NaH + H. (Czechoslovakia) Using a Pirani gauge, removal of hydrogen from gas phase by excited sodium atoms according to the reaction Na* + Hz + NaH + H is measured in a vessel containing hydrogen at pressures less than 3 x 1O-2 torr and sodium vapour at pressure 8.9 x 10m5 torr and irradiated by resonance radiation. The experiments were performed in a glass system initially evacuated to 1Om6torr. A Netten, Proc of 11th Znternat Conf on Phenom in Ionized Gases, Prague 1973,46. 18 551. Study of the nitridation of magnesium in nitrogen dc glow discharge. (Czechoslovakia) Nitridation of magnesium is studied in a dc glow discharge in nitrogen at a pressure of 5 x 10-l torr in dependence on the position of magnesium in the discharge tube, its polarity and temperature. It is found that the contribution of thermal nitridation is inessential and the concentration of particles and their space distribution is decisive in the mechanism on nitridation. J Kodymova and L La&a, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973, 47. 178

18 552. Measurement of dissociation in CO, discharge by means of acoustic wave velocity. (Czechoslovakia) The velocity of the travelling sound wave was measured as a function of time in a plasma of discharge in CO, at an initial pressure of 2.6 torr and discharge current of 6 mA. It is shown that the method of measurement of acoustic wave velocity is useful for determination of the time development of gas composition and its temperature changes. L Pekarek et al, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,48. 18 553. Electron attachment in oxygen-carbon dioxide mixtures. (Czechoslovakia) The electron attachment coefficient and the real attachment coefficient are determined for oxygen from the measurement of the dependence of apparent attachment coefficient in mixtures of OS-COz on the CO, concentration. The current growth studies were carried out in an ultrahigh vacuum apparatus. (England) D A Price and J L Moruzz, Proc of 11th Internal Conf on Phenom bz Zoniz Gases, Prague 1973, 49. _ 18 554. Negative ions in sulphnr dioxide. (Czechoslovakia) Negative ion formation in SO, in swarm conditions is studied in a drift tube using a pulse technique for investigation of waveforms of electrons and ions and a mass analysis. A quadrupole mass spectrometer chamber with a pressure less than low4 torr was connected to the drift tube with a pressure above 10 torr by a set of 25 pm holes in the 15 pm nickel foil anode. (France) Y Le Coat et al, Proc of 11th Internat Conf on Phenom in Zoniz Gases, Prague 1973,52. 18 555. Chemical reactions in weakly ionized gases of hydrocarbons and perfluorocarbons. (Czechoslovakia) Chemical reactions of positive ions have been observed in gaseous CH,-CF, mixtures in an ion source of mass spectrometer at pressures up to 0.52 torr. (USA) E Heckel, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,55. 18 556. The time behaviour of electric field in column of a dc discharge in &H,-Ne Penning mixtures. (Czechoslovakia) The axial potential gradient is measured in a dc discharge in neon at a pressure of 1.6 torr and a small admixture of CsH6. The experimental results are discussed from the view point of the mechanism of glow discharge in which polymerization of a monomer occurs. (Germany) H Sabadil and H Deutsch, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973, 56. 18 557. Chemical processes in radio-frequency discharges at moderate pressures. (Czechoslovakia) The synthesis of HCN from N,-CH, mixtures, conversion of methane into acetylene and heterogeneous reduction of metal oxides of Cu, Ni, Pb and Zn in a hydrogen plasma have been investigated in detail in the pressure range of 5 to 75 torr. Chemical processes involved in radio-frequency discharges are discussed. (Italy) P Capezzuto et al, Proc of 11th Znternat Conf on Phenom in Ioniz Gases, Prague 1973, 57. 18 558. ArHg+-ions in the mercury-argon low pressure discharge-mass spectrometric analysis of the formation process. (Czechoslovakia) Using an extraction probe with mass spectrometric analysis, f&mation of Ar,+ and ArHg+ ions in a H&u low oressure discharge is investigated in dependence on discharge current in the range of 3 to 200 mA, mercury pressure 5 x 10m4 to 1.5 x 10-l torr and argon pressure 1 x 10m2 to 10 torr. (Germany) G Franck et al, Proc of 11th Znternat Conf on Phenom in Zoniz Gases, Prague 1973,lO. 18 559. Nonindependent discharge in nitrogen with volume ionization by ultraviolet radiation. (Czechoslovakia) It is experimentally shown that a nonindependent discharge may exist in nitrogen at high pressure at external ionization by ultraviolet