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Electron impact relative ionization cross sections and fragmentation of U, UO, UO2 and UO3
Classified abstracts 23-35 collective interaction of positive and negative hydrogen ion beams with currents up to 2 mA and energy of 13 keV in vacuum is experimentally investigated. It is shown that phase focusing of particles during development of beam instability results in strong nonlinear interaction between the beams and intense energy exchange between them occurs. M D Gabovich and A P Nayda, Zh Eksper Teor Fiz, 62 (I), Jan 1972, 183-188 (in Russian). 18 23. Influence of resonance radiation on the properties and parameters of caesium plasma. (USSR) Influence of resonance radiation generated in a power arc discharge in caesium vapour at 2 x 10 -x torr on the properties and parameters of the caesium plasma of a steady low-voltage arc discharge with hot cathode in caesium vapour at pressures lower than 2 x 10-1 torr is studied using a mass spectrometric method. N D Morgulis and A M Przhonskiy, Zh Tekh Fiz, 42 (2), Feb 1972, 344-348 (in Russian). 18 24. Physical processes in an impulse discharge in dielectric chambers. (USSR) Physical processes in an impulse discharge under conditions where sublimation of the discharge chamber walls (organic glass or fluoroplastic) occurs, are considered. Ionization equilibrium is reached only for first degree of ionization. The main part of energy of plasma is lost by radiation. Destruction of the wall material begins after 1-2 ~ts after discharge initiation and the temperature of the chamber surface attains about 850°C. A I Zemskov et al, Zh Tekh Fiz, 42 (2), Feb 1972, 358-363 (in Russian). 18 25. Dissociative recombination in a gas discharge. (USSR) The mechanism of electron-ion dissociative recombination of N2 + in a gas discharge is considered on the basis of an analysis of theoretical and experimental results on microwave and glow discharges at 0.3 to 2 tort. V F Babalyants et al, Optika Spektroskop, 32 (2), Feb 1972, 249-251
(in Russian). 18 26. Measurement of the cross sections of the processes of ion-atom collisions in the collision energy range 200 to 3000 eV. (USSR) An experimental apparatus for investigation of inelastic atomic collisions at energies of 200-3000 eV is described. The measurement is based on recording slow ions generated in a gas during passage of a pulsed ion beam through gas. The experimental apparatus is evacuated by oil diffusion pumps. Z Z Latypov and A A Shaporenko, Zh Tekh Fiz, 42 (1), Jan 1972, 151-158 (in Russian). 18 27. Determination of the Planck constant and electron work function of a metal by the method of charge accumulation. (USSR) The electron work function of a metal is determined by measurement of the retarding field required to suppress the photocurrent in a vacuum photocell. A new method of determining the retarding voltage by charge accumulation in a capacitor connected to the photocell, is presented. V I Shulga and V I Shramko, lzv VUZ Fiz, No 1, 1972, 130-131 (in
Russian). 18 28. Production of high-temperature deuterium plasma by laser irradiation of a special gas target. (USSR) An estimate is made of the electron temperature during laser heating of a deuterium plasma. A special gas target consisting of a cylindrical tube closed at the ends by thin films and filled with deuterium is considered. Optimization of the experimental parameters such as pulse duration and tube diameter is carried out for various initial gas pressures and external longitudinal magnetic field strengths. The dependence of plasma temperature and neutron yield on laser pulse energy is calculated for the optimum configuration. P P Pashinin and A M Prokhorov, Zh Eksper Teor Fiz, 62 (1), Jan 1972, 189-194 (in Russian). 18 29. Investigation of drift-beam instability of the system plasma-ion beam in longitudinal magnetic field. (USSR) Drift-beam instability in a plasma-ion beam system immersed in
longitudinal magnetic field is studied both experimentally and theoretically. It is found that in a system consisting of two opposite ion beams of helium or argon with equal currents and energies, moving through their own gas at pressures of 2× 10 -s to 7× 10 -4 torr along a magnetic field of 2-10 kOe, oscillations are excited with frequencies several times greater than the corresponding ion-cyclotron frequencies. M D Gabovich et al, Zh Eksper Teor Fiz, 62 (1), Jan 1972, 195-202
(in Russian). 18 30. A method of precision analysis of spectra of inelastic energy losses at atomic eofiisions. (USSR) An experimental arrangement for investigating the spectra of inelastic losses of energy in atomic collisions, by means of the coincidence method, is described. A high-frequency ion source, magnetic mass monochromater, and electrostatic energy and charge analysers are used. V V Afrosimov et al, Zh Tekh Fiz, 42 (1), Jan 1972, 125-133 (in Russian). 18 31. Cross sections of disturbance and charge transfer of halogen negative ions at energies of 300-3000 eV. (USSR) Results of measurements of the cross sections of charge transfer and disturbance of negative halogen ions with energies between 300 and 3000 eV on targets of 02, CO2, I2, CL2 and SFe are presented. The experimental set-up with magnetic analyser is described. A thermionic emitter of lanthanum hexaboride working in an ambient of working gas at 10 -4 to 10 -5 tort is used to generate the negative ions. G I Dimov and G V Roslyakov, Zh Tekh Fiz, 42 (1), Jan 1972, 118124 (in Russian). 18 32. Influence of dc electric field on the stability of a resonance highfrequency discharge. (USSR) Resonance high-frequency discharge in an evacuated toroidal resonator is investigated in the ultra-high frequency region at residual gas pressure of 1 x 10- e torr. It is found that the regions of instability of the discharge develop on the application of a dc electric field with intensity of 100-500 V/cm. V A Stanskiy et al, Zh Tekh Fiz, 42 (1), Jan 1972, 79-82 (in Russian). 18 33. High-frequency discharge in a coaxial resonator with external magnetic field. (USSR) In cases, when high-frequency voltage is applied to a vacuum gap, resonance high-frequency discharge may appear. Two- and oneelectrode modes of high-frequency discharge are distinguished. The necessary condition of discharge development is that the coefficient of secondary emission of electrode surface should be higher than unity. Conditions of existence of resonance high-frequency discharge and one-electrode high-frequency discharge in an evacuated coaxial resonator are studied in the presence of an external longitudinal magnetic field. A pressure increase in the resonator is observed at discharge development. Experimental results are discussed. G A Ivanov and Z G Gavrilova, Zh Tekh Fiz, 42 (l),Jan 1972, 71-78
(in Russian). 18 34. Hollow-cathode discharge in magnetic field. (USSR) Influence of a transverse magnetic field on the volt-ampere characteristics of a hollow-cathode discharge is investigated at helium pressures between 0.3 and 5 torr. It is shown that the magnetic field decreases the maintaining voltage of the discharge, amplifies the hollow cathode effect, and brings it into the region of higher pressures. V M Tkachenko and V B Tyutyunnik, Zh Tekh Fiz, 42 (1), Jan 1972, 67-70 (in Russian). 18 35. Electron impact relative ionization cross sections and fragmentation of U, UO, UO2 and UO3. (USA) The system consisted of a Knudsen cell, mass spectrometer, and vacuum balance. Electron energies from 4 to 60 V were used. Because the molecules are extensively fragmented, both total relative ionization cross sections and cross sections for production of parent ions are given. Values are tabulated as a function of ionizing voltage. The results are discussed in some detail. P E Blackburn and P M Danielson, J Chem Phys, 56 (12), 15th June 1972, 6156-6164. 33
(in Russian). 18 26. Measurement of the cross sections of the processes of ion-atom collisions in the collision energy range 200 to 3000 eV. (USSR) An experimental apparatus for investigation of inelastic atomic collisions at energies of 200-3000 eV is described. The measurement is based on recording slow ions generated in a gas during passage of a pulsed ion beam through gas. The experimental apparatus is evacuated by oil diffusion pumps. Z Z Latypov and A A Shaporenko, Zh Tekh Fiz, 42 (1), Jan 1972, 151-158 (in Russian). 18 27. Determination of the Planck constant and electron work function of a metal by the method of charge accumulation. (USSR) The electron work function of a metal is determined by measurement of the retarding field required to suppress the photocurrent in a vacuum photocell. A new method of determining the retarding voltage by charge accumulation in a capacitor connected to the photocell, is presented. V I Shulga and V I Shramko, lzv VUZ Fiz, No 1, 1972, 130-131 (in
Russian). 18 28. Production of high-temperature deuterium plasma by laser irradiation of a special gas target. (USSR) An estimate is made of the electron temperature during laser heating of a deuterium plasma. A special gas target consisting of a cylindrical tube closed at the ends by thin films and filled with deuterium is considered. Optimization of the experimental parameters such as pulse duration and tube diameter is carried out for various initial gas pressures and external longitudinal magnetic field strengths. The dependence of plasma temperature and neutron yield on laser pulse energy is calculated for the optimum configuration. P P Pashinin and A M Prokhorov, Zh Eksper Teor Fiz, 62 (1), Jan 1972, 189-194 (in Russian). 18 29. Investigation of drift-beam instability of the system plasma-ion beam in longitudinal magnetic field. (USSR) Drift-beam instability in a plasma-ion beam system immersed in
longitudinal magnetic field is studied both experimentally and theoretically. It is found that in a system consisting of two opposite ion beams of helium or argon with equal currents and energies, moving through their own gas at pressures of 2× 10 -s to 7× 10 -4 torr along a magnetic field of 2-10 kOe, oscillations are excited with frequencies several times greater than the corresponding ion-cyclotron frequencies. M D Gabovich et al, Zh Eksper Teor Fiz, 62 (1), Jan 1972, 195-202
(in Russian). 18 30. A method of precision analysis of spectra of inelastic energy losses at atomic eofiisions. (USSR) An experimental arrangement for investigating the spectra of inelastic losses of energy in atomic collisions, by means of the coincidence method, is described. A high-frequency ion source, magnetic mass monochromater, and electrostatic energy and charge analysers are used. V V Afrosimov et al, Zh Tekh Fiz, 42 (1), Jan 1972, 125-133 (in Russian). 18 31. Cross sections of disturbance and charge transfer of halogen negative ions at energies of 300-3000 eV. (USSR) Results of measurements of the cross sections of charge transfer and disturbance of negative halogen ions with energies between 300 and 3000 eV on targets of 02, CO2, I2, CL2 and SFe are presented. The experimental set-up with magnetic analyser is described. A thermionic emitter of lanthanum hexaboride working in an ambient of working gas at 10 -4 to 10 -5 tort is used to generate the negative ions. G I Dimov and G V Roslyakov, Zh Tekh Fiz, 42 (1), Jan 1972, 118124 (in Russian). 18 32. Influence of dc electric field on the stability of a resonance highfrequency discharge. (USSR) Resonance high-frequency discharge in an evacuated toroidal resonator is investigated in the ultra-high frequency region at residual gas pressure of 1 x 10- e torr. It is found that the regions of instability of the discharge develop on the application of a dc electric field with intensity of 100-500 V/cm. V A Stanskiy et al, Zh Tekh Fiz, 42 (1), Jan 1972, 79-82 (in Russian). 18 33. High-frequency discharge in a coaxial resonator with external magnetic field. (USSR) In cases, when high-frequency voltage is applied to a vacuum gap, resonance high-frequency discharge may appear. Two- and oneelectrode modes of high-frequency discharge are distinguished. The necessary condition of discharge development is that the coefficient of secondary emission of electrode surface should be higher than unity. Conditions of existence of resonance high-frequency discharge and one-electrode high-frequency discharge in an evacuated coaxial resonator are studied in the presence of an external longitudinal magnetic field. A pressure increase in the resonator is observed at discharge development. Experimental results are discussed. G A Ivanov and Z G Gavrilova, Zh Tekh Fiz, 42 (l),Jan 1972, 71-78
(in Russian). 18 34. Hollow-cathode discharge in magnetic field. (USSR) Influence of a transverse magnetic field on the volt-ampere characteristics of a hollow-cathode discharge is investigated at helium pressures between 0.3 and 5 torr. It is shown that the magnetic field decreases the maintaining voltage of the discharge, amplifies the hollow cathode effect, and brings it into the region of higher pressures. V M Tkachenko and V B Tyutyunnik, Zh Tekh Fiz, 42 (1), Jan 1972, 67-70 (in Russian). 18 35. Electron impact relative ionization cross sections and fragmentation of U, UO, UO2 and UO3. (USA) The system consisted of a Knudsen cell, mass spectrometer, and vacuum balance. Electron energies from 4 to 60 V were used. Because the molecules are extensively fragmented, both total relative ionization cross sections and cross sections for production of parent ions are given. Values are tabulated as a function of ionizing voltage. The results are discussed in some detail. P E Blackburn and P M Danielson, J Chem Phys, 56 (12), 15th June 1972, 6156-6164. 33