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1216. Production of quiescent discharge with high electron temperatures
Classified abstracts 1207-1221 18 1207. Plasma heating by an electron beam. (USSR) The energy distribution of ions during heating of the electron component in a plasma-beam system was experimentally investigated. V A Saenko and V A Zhdanov, Radiotekh Elektron, 13 (3), March 1968, 554-557 (in Russian). 18 1208. Plasma diagnostics by comman-mode RF probe. (USSR) A new method for rapid measurement of the electron temperature of plasma is described. Using this method, plasma from a discharge in mercury and helium at 10-3 to 3 x 10-z torr was investigated. V A Godyak and A A Kuzovnikov, Radiotekh Electron, 13 (3), March 1968, 557-560 (in Russian). 18 1209. The work function of alloys of rhenium with rare-earth metals of the yttrium group and gadolinium. (USSR) The following values of the work function were obtained at 1300°K (the number preceding the rare-earth symbol indicates the weight per cent): Re-4Y, 2.98 eV; Re-4.4Gd, 2.90 eV; Re-5Tb, 2.95 eV; Re-4Dy, 2.90 eV; Re-3Ho, 2.95 eV; Re-2.5 Er, 3.00eV; Re-3Tu, 2.85 eV; and Re-4Lu, 3.20 eV. Temperature coefficients 1 x 10-4 to 4 x 10-4 eV/grad were determined for the work functions in the range 1100 to 1500°K. S E Rozhkov and O K Knltashev, Radiotekh Elektron, 13 (3), March 1968, 570-571 (in Russian). 18 1210. Yttrium and lanthanum secondary electron emission. (USSR) The secondary electron emission coefficient, which has a maximum value of 0.93 at 350 eV for yttrium and 1.03 at 500 eV for lanthanum, and the nonelastic reflection coefficient were determined for primary beams of 200 to 3000 eV. L A Ermolaev and Yu K Tsupko, Radiotekh Elektron, 13 (3), March 1968, 571-573 (in Russian). 18 1211. Strata. (USSR) Literature on the formation of layers in the positive column of a gas discharge is reviewed. After a summary of previously published experimental data, the nature of the strata is discussed. A review of experimental and theoretical knowledge of magnetic strata is included. 140 references are given. A V Nedospasov, Uspekhi Fiz Nauk, 94 (3), March 1968, 439-462
(in Russian). 18 1212. The ionization waves (strata) in discharge plasma. (USSR) The phenomenological properties of ionization waves (strata) in different gases is reviewed with the main emphasis on artificially excited ionization waves with small amplitudes. 189 references are added. (Czechoslovakia) L Pekarek, Uspekhi Fiz Nauk, 94 (3), March 1968, 463-500 (in
Russian). 18 1213. Plasma instabilities excited by an azimuthal electron beam. (Czechoslovakia) The instabilities for which the longitudinal macroscopic velocity of the beam is of no importance are discussed. K Jongwirth, Czech J Phys, B18 (5), 1968, 629-634 (in English). 18:63 1214. International symposium on beam-plasma interactions. (Czechoslovakia) Brief details are given of the Symposium which was held in Prague, Czechoslovakia, in September 1967. The opening address and authors abstracts of all 28 presented papers are included. The invited review paper "Interaction of beams of charged particles with plasma", by Ya B Fainberg, is presented in full. M Seidl, Czech JPhys, BIB (5), 1968, 649-692 (in English). 18 1215. Afterglow spectrum of an rf mercury discharge. (USA) The short duration afterglow of an rf discharge in mercury has been investigated as a function of mercury temperature and rf power. The experimental cell was prepared on an oil diffusion pump system which gave a vacuum of 2 x 10-8 torr by outgassing the Pyrex cell at 400°C. The cell was filled with triply distilled mercury, which was vacuum distilled into the cell in two stages. The techniques and results are discussed. J A Auhrecht et al, J Opt Soc Amer, 58 (2), 1968, 196-203.
18 1216. Production of quiescent discharge with high electron temperatures. (USA) Collisionless steady state plasmas showing a remarkably low level of fluctuations have been generated in a mirror-geometry magnetic field by applying radio-frequency power to a coupling structure of a new design. This mode of plasma generation has been carried out, and plasmas with electron densities of 10z° to 1011 cm -3 with electron temperatures of 10 to 30 eV were produced in various gases at pressures as low as 10-5 torr. G Lisituno et al, Rev Sci Instrum, 39 (3), 1968, 295-297. " 18:30 1217. Calculation of ion bombarding energy and its distribution in rf sputtering. (USA) The energy distribution of bombarding ions was calculated with numerical integration by computer of the Mathieu-type equations of motions of ions and electrons in the cathode-fall region with various initial and boundary conditions. The self-biased component was found to be 0.99928 of one-half the peak-to-peak rf potential applied across the cathode dark space, which is in agreement with the value obtained from mobility considerations. The ion energy distribution was found to depend on the rf voltage and frequency, dark space distance, and the ratio of electron to ion mass. The effect of high electron temperature on the ion energy distribution was found to be very small. Trajectories of both ions and electrons in the cathode-fall region were calculated. R T C Tsui, Phys Rev, 168 (1), 5th April 1968, 107-113. 18:30 1218. Etlieient sputtering in a cold-cathode discharge in magnetron geometry. (USA) Efficient sputtering was achieved in a cold-cathode discharge in a magnetron geometry under a strong magnetic field. The sputtering may readily be applied to the production of thin film microcircuits. The sputtering mechanism is discussed in connection with the mode of discharge. K Wasa and S Hayakawa, Proc IEEE, 55 (12), Dec 1967, 2179-2180 18 1219. Binding and field desorption of individual tungsten atoms. (USA) The binding energy of individual tungsten atoms on different planes of a tungsten crystal has been explored by field desorption at 20°K. Ttmnelling, rather than evaporation over a Schottky saddle, is the limiting step under these conditions. The appropriate relations between desorption field and atomic binding are derived and tested by establishing the evaporation field for tungsten at 6.l V/A. Binding energies from desorption measurements on single adatoms are quoted for several planes. The work was carried out under ultrahigh vacuum conditions in a bakeable microscope. G Ehrlieh and C F Kirk, J Chem Phys, 48 (4), 15th February 1968, 1465-1482. 18 1220. Surface ionization. III. The first ionization potentials of the lanthanides. (USA) The surface ionization comparison technique was used to measure the first ionization potentials of the lanthanide elements. Values obtained were: La, 5.55=1=0.05 eV, Ce, 5.544-0.06, Pr, 5.404-0.05, Nd, 5.494-0.05, Sin, 5.614-0.05, Eu, 5.644-0.05, Gd, 6.164-0.05, Tb, 5.894-0.04, Dy, 5.824-0.03, Ho, 5.894-0.03, Er, 5.95+0.03, Tin, 6.034-0.04, Yb, 6.044-0.04 and Lu, 5.324-0.05. The IP of Pm is estimated to be 5.55 eV. The reference element used was silver. A tabulation of all known reported values is included, and comparisons are made. A single-focusing, magnetic mass spectrometer was used, with a polycrystalline tungsten ribbon for the ionizing surface. Operating pressure was less than 10-s torr. G R Hertel, J Chem Phys, 48 (5), 1st March 1968, 2053-2058. 18 1221. Gaseous ion recombination. V. (USA) This is a theoretical paper in which Pitaevski's formulation of the three-body ion-electron recombination rate constant based on the Fokker-Planck equation is modified so as to apply to the termolecular association of gaseous ions. The theory is expected to be valid when the collisional energy changes are small compared to the kinetic energy of the recombining ions. This occurs when the mass of the neutral is much less than the masses of the ions. B H Makan, J Chem Phys, 48 (6), 15th March 1968, 2069-2072. 531
(in Russian). 18 1212. The ionization waves (strata) in discharge plasma. (USSR) The phenomenological properties of ionization waves (strata) in different gases is reviewed with the main emphasis on artificially excited ionization waves with small amplitudes. 189 references are added. (Czechoslovakia) L Pekarek, Uspekhi Fiz Nauk, 94 (3), March 1968, 463-500 (in
Russian). 18 1213. Plasma instabilities excited by an azimuthal electron beam. (Czechoslovakia) The instabilities for which the longitudinal macroscopic velocity of the beam is of no importance are discussed. K Jongwirth, Czech J Phys, B18 (5), 1968, 629-634 (in English). 18:63 1214. International symposium on beam-plasma interactions. (Czechoslovakia) Brief details are given of the Symposium which was held in Prague, Czechoslovakia, in September 1967. The opening address and authors abstracts of all 28 presented papers are included. The invited review paper "Interaction of beams of charged particles with plasma", by Ya B Fainberg, is presented in full. M Seidl, Czech JPhys, BIB (5), 1968, 649-692 (in English). 18 1215. Afterglow spectrum of an rf mercury discharge. (USA) The short duration afterglow of an rf discharge in mercury has been investigated as a function of mercury temperature and rf power. The experimental cell was prepared on an oil diffusion pump system which gave a vacuum of 2 x 10-8 torr by outgassing the Pyrex cell at 400°C. The cell was filled with triply distilled mercury, which was vacuum distilled into the cell in two stages. The techniques and results are discussed. J A Auhrecht et al, J Opt Soc Amer, 58 (2), 1968, 196-203.
18 1216. Production of quiescent discharge with high electron temperatures. (USA) Collisionless steady state plasmas showing a remarkably low level of fluctuations have been generated in a mirror-geometry magnetic field by applying radio-frequency power to a coupling structure of a new design. This mode of plasma generation has been carried out, and plasmas with electron densities of 10z° to 1011 cm -3 with electron temperatures of 10 to 30 eV were produced in various gases at pressures as low as 10-5 torr. G Lisituno et al, Rev Sci Instrum, 39 (3), 1968, 295-297. " 18:30 1217. Calculation of ion bombarding energy and its distribution in rf sputtering. (USA) The energy distribution of bombarding ions was calculated with numerical integration by computer of the Mathieu-type equations of motions of ions and electrons in the cathode-fall region with various initial and boundary conditions. The self-biased component was found to be 0.99928 of one-half the peak-to-peak rf potential applied across the cathode dark space, which is in agreement with the value obtained from mobility considerations. The ion energy distribution was found to depend on the rf voltage and frequency, dark space distance, and the ratio of electron to ion mass. The effect of high electron temperature on the ion energy distribution was found to be very small. Trajectories of both ions and electrons in the cathode-fall region were calculated. R T C Tsui, Phys Rev, 168 (1), 5th April 1968, 107-113. 18:30 1218. Etlieient sputtering in a cold-cathode discharge in magnetron geometry. (USA) Efficient sputtering was achieved in a cold-cathode discharge in a magnetron geometry under a strong magnetic field. The sputtering may readily be applied to the production of thin film microcircuits. The sputtering mechanism is discussed in connection with the mode of discharge. K Wasa and S Hayakawa, Proc IEEE, 55 (12), Dec 1967, 2179-2180 18 1219. Binding and field desorption of individual tungsten atoms. (USA) The binding energy of individual tungsten atoms on different planes of a tungsten crystal has been explored by field desorption at 20°K. Ttmnelling, rather than evaporation over a Schottky saddle, is the limiting step under these conditions. The appropriate relations between desorption field and atomic binding are derived and tested by establishing the evaporation field for tungsten at 6.l V/A. Binding energies from desorption measurements on single adatoms are quoted for several planes. The work was carried out under ultrahigh vacuum conditions in a bakeable microscope. G Ehrlieh and C F Kirk, J Chem Phys, 48 (4), 15th February 1968, 1465-1482. 18 1220. Surface ionization. III. The first ionization potentials of the lanthanides. (USA) The surface ionization comparison technique was used to measure the first ionization potentials of the lanthanide elements. Values obtained were: La, 5.55=1=0.05 eV, Ce, 5.544-0.06, Pr, 5.404-0.05, Nd, 5.494-0.05, Sin, 5.614-0.05, Eu, 5.644-0.05, Gd, 6.164-0.05, Tb, 5.894-0.04, Dy, 5.824-0.03, Ho, 5.894-0.03, Er, 5.95+0.03, Tin, 6.034-0.04, Yb, 6.044-0.04 and Lu, 5.324-0.05. The IP of Pm is estimated to be 5.55 eV. The reference element used was silver. A tabulation of all known reported values is included, and comparisons are made. A single-focusing, magnetic mass spectrometer was used, with a polycrystalline tungsten ribbon for the ionizing surface. Operating pressure was less than 10-s torr. G R Hertel, J Chem Phys, 48 (5), 1st March 1968, 2053-2058. 18 1221. Gaseous ion recombination. V. (USA) This is a theoretical paper in which Pitaevski's formulation of the three-body ion-electron recombination rate constant based on the Fokker-Planck equation is modified so as to apply to the termolecular association of gaseous ions. The theory is expected to be valid when the collisional energy changes are small compared to the kinetic energy of the recombining ions. This occurs when the mass of the neutral is much less than the masses of the ions. B H Makan, J Chem Phys, 48 (6), 15th March 1968, 2069-2072. 531