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1155. High-frequency modulation of atomic particle beams in active corpuscular diagnostics of plasma
Classified abstracts
1142-I 155
of gallium arsenide lattice and complex ions type Ga,As. have been observed in the spectrum of charged particles. Besides these, ions of molecules of surface compounds of lattice elements with residual gas molecules have been found. The composition of ejected neutral particles considerably differs from that of secondary ions. A G Koval et al, Zh Tekh Fiz, 44 (12), 1974, 2563-2567 (in Russian). 18 1142. Heated probe in the field of rarefied plasma. (USSR)
Features of operation of a mentally and theoretically. synthetized plasma of 100 electrons emitted from a hot E M Netsvetaylov Russian).
heated probe are studied both experiThe experiments were performed in a eV argon ion beam neutralized with tungsten filament.
et al, Zh Tekh Fiz, 44 (12), 1974, 2551-2558
(in
18 1143. To the problem of anomalously high emission from nonevaporating thermionic cathode in arc discharge. (USSR) The factors, which could result in enhancement of emission from tungsten thermionic cathode in arc discharge at a pressure of 0.1 to 1 atm of plasma-forming gas, are considered. A calculation of the influence of fluctuations of electric field on cathode surface due to individual ion charges is presented. The influence of electron emission cooling and formation of microroughness on cathode surface is also studied. B Ya Moyzhes and V A Nemchinskiy, Zh 7’ekh Fiz, 44 (12), 1974, 2539-2547 (in Russian). 1144. Experimental investigation with plasma. (USSR)
18 of tubular electron beam interaction
Using the method of probes, collective interaction of a 100 keV, 100 A, 2 ~LStubular electron beam, generated in a magnetron gun, with a plasma is investigated. The plasma was produced in hydrogen by ionization by an 20 keV, 15 A, 120 ps auxiliary electron beam. The most efficient interaction was observed in a narrow hydrogen pressure interval of 2 x 10e5 to 7 X 10e5 torr. N M Zemlyanskiy et al, Zh Tekh Fiz, 44 (12), 1974, 250&2503 (in Russian). 1145. On the theory of self-sustained closed drift of electrons. I. (USSR)
low-pressure
discharge
18 with
Using a diffusion approximation, structure of anode layer in a highvoltage low-pressure discharge with closed Hall current is studied. Such discharges are used for generation and acceleration of intensive ion beams. It is shown that the dependence of ionization coefficient on electron energy and inelastic losses of energy considerably influence characteristics of the discharge. V K Kalashnikov and Yu V Sanochkin, Zh Tekh Fiz, 44 (l2), 1974, 2504-2511 (in Russian). 18 1146. On the theory of self-sustained closed drift of electrons. II. (USSR)
low-pressure
discharge
with
Distribution of concentratidn, aveiage electron energy, electric field, electron and ion currents in the anode layer of a self-sustained lowpressure discharge with closed drift of electrons are obtained. The iesults of calcul&on are compared with the experimental data. Yu V Sanochkinov and V K Kalashnikov. Zh Tekh Fiz. , 44 (12). .,, 1974., 2512-2518 (in Russian). 18 1147. Field electron emission from tantalum covered with thin film of SiO and A1203. (Bulgaria) Using the probe method in a field electron emission microscope, emission properties of tantalum covered with adsorbed films of SiO and A1203 are investigated. Work function of the whole emitting surface is determined. It is concluded that the dielectric film produces widening of the barrier for electrons emitted from metal. K Bobev and Z Mireva, Rep of Inst of Electronics of Bulg Acad of Scienc, No 7, 1974, 1l-17 (in Bulgarian). 18 1148. Spectral dependence of exit depth of photoelectrons from (Cs, Rb),Sb. (Bulgaria) The relation between the excitation energy and effective free path of photoelectrons in (Cs, Rb)$b is investigated. It is found that maximum exit depth occurs at photo-emission threshold and it decreases
with excitation
energy increase. It is noted that large exit depth of
500 nm of photoelectrons from (Cs, Rb)$b results in high integral sensitivity of this photocathode in comparison with Cs,Sb. K Nanev et al, Rep of Inst of Electron of Buig Acad of Scienc, No 7, 1974, 19-22 (in Bulgarian). I8 1149. Experimental investigation of electron loss and capture by fast unexcited and metastable helium-like ions in ion-atomic collisions.
(USSR) The average cross sections for loss or capture of one to two electrons are determined in a mass-spectrometric apparatus for beams of helium-like particles containing a metastable component, produced by passage of cyclotron-accelerated B’ +, B2+, C3+ and N6+ ions through gas target or a thin celluloid film. I S Dmitriev et al, Zh Eksper Teor Fiz, 67 (6), 1974. 2047-2063 (in Russian). 1150.
Solitary
charge
density
waves
in a magnetoactive
18 plasma.
(USSR) It is shown that a charge density wave moving obliquely to a magnetic field may have the shape of a solitary electron bunch (charge density sol&on). The experiments were performed in a cylindrical plasma waveguide filled with argon to a pressure of 1 x 10e4 to 5 x lo-“ torr. Plasma was produced by collisions with electrons emitted from a hot cathode. S M Krivoruchko et al, Zh Eksper Teor Fir, 67 (6), 1974, 2092-2103 (in Russian). 18 1151. Mass-spectrometric investigation of the photoionization processes of tetranitromethane and its baloide derivatives. (USSR) Using a photoionization mass spectrometer, primary photoionization process in tetranitromethane and its haloide derivatives are investi-
gated in the energy interval of 11 to 14 eV. It is found that NO+ and NOz+ ions are formed as a result of dissociative photoionization of molecules. V K Potapov et al, Khim Vysok Energiy, 8 (3), 1974, 286287 (in Russian). 1152. Photoelectron emission from aromatic charge-transfer -caesium. (USSR)
18 complexes
Variations in spectral dependence of quantum yield of photoelectron emission from aromatic charge-transfer complexes at deposition of caesium on their surface are investigated in a vacuum ofm10-8 torr. V V Aleksandrov et al, Izv AN Latv SSR Ser Fiz Tekh Nauk. No 2. 1974, 114-l 17 (in Russian). 1153. Axial variations in characteristics of discharge hollow cathode in helium and argon. (USSR)
18 in magnesium
Using the method of probes, axial variations in characteristics of discharge in magnesium hollow cathode in helium and argon are measured. Measurements were performed at pressures ranging from 6 x 10mz to 3 torr. F Kidrasov et al, Vestn Mosk 232-235 (in Russian).
Univ
Fiz Astronom,
15 (2),
1974,
18 1154. Investigation of radial distribution of concentration of charged particles and potentila in column of glow discharge in CO, and water vapour. (USSR)
Using a method of single probe, radial distribution of concentration of positive ions and potential in column of glow discharge in CO1 and water vapour is measured in the pressure range of 0.5 to 2 torr and currents of 1 to 5 mA. A I Mksimov and V F Sokolov, Zh Tekh Fiz, 44 (lo), 1974, 2198-2202 (in Russian). I8 1155. High-frequency modulation of atomic particle beams in active corpuscular diagnostics of plasma. (USSR)
A proton beam with IO4 eV energy was modulated with lo6 Hz frequency and used for probing of dense plasma formations. Modulation of the beam was performed with the aid of a charge-exchange gas target. P A Demchenko et al., Zh Tekh Fir, 44 (lo), 1974. 2203-2210 (in Russian). 393
1142-I 155
of gallium arsenide lattice and complex ions type Ga,As. have been observed in the spectrum of charged particles. Besides these, ions of molecules of surface compounds of lattice elements with residual gas molecules have been found. The composition of ejected neutral particles considerably differs from that of secondary ions. A G Koval et al, Zh Tekh Fiz, 44 (12), 1974, 2563-2567 (in Russian). 18 1142. Heated probe in the field of rarefied plasma. (USSR)
Features of operation of a mentally and theoretically. synthetized plasma of 100 electrons emitted from a hot E M Netsvetaylov Russian).
heated probe are studied both experiThe experiments were performed in a eV argon ion beam neutralized with tungsten filament.
et al, Zh Tekh Fiz, 44 (12), 1974, 2551-2558
(in
18 1143. To the problem of anomalously high emission from nonevaporating thermionic cathode in arc discharge. (USSR) The factors, which could result in enhancement of emission from tungsten thermionic cathode in arc discharge at a pressure of 0.1 to 1 atm of plasma-forming gas, are considered. A calculation of the influence of fluctuations of electric field on cathode surface due to individual ion charges is presented. The influence of electron emission cooling and formation of microroughness on cathode surface is also studied. B Ya Moyzhes and V A Nemchinskiy, Zh 7’ekh Fiz, 44 (12), 1974, 2539-2547 (in Russian). 1144. Experimental investigation with plasma. (USSR)
18 of tubular electron beam interaction
Using the method of probes, collective interaction of a 100 keV, 100 A, 2 ~LStubular electron beam, generated in a magnetron gun, with a plasma is investigated. The plasma was produced in hydrogen by ionization by an 20 keV, 15 A, 120 ps auxiliary electron beam. The most efficient interaction was observed in a narrow hydrogen pressure interval of 2 x 10e5 to 7 X 10e5 torr. N M Zemlyanskiy et al, Zh Tekh Fiz, 44 (12), 1974, 250&2503 (in Russian). 1145. On the theory of self-sustained closed drift of electrons. I. (USSR)
low-pressure
discharge
18 with
Using a diffusion approximation, structure of anode layer in a highvoltage low-pressure discharge with closed Hall current is studied. Such discharges are used for generation and acceleration of intensive ion beams. It is shown that the dependence of ionization coefficient on electron energy and inelastic losses of energy considerably influence characteristics of the discharge. V K Kalashnikov and Yu V Sanochkin, Zh Tekh Fiz, 44 (l2), 1974, 2504-2511 (in Russian). 18 1146. On the theory of self-sustained closed drift of electrons. II. (USSR)
low-pressure
discharge
with
Distribution of concentratidn, aveiage electron energy, electric field, electron and ion currents in the anode layer of a self-sustained lowpressure discharge with closed drift of electrons are obtained. The iesults of calcul&on are compared with the experimental data. Yu V Sanochkinov and V K Kalashnikov. Zh Tekh Fiz. , 44 (12). .,, 1974., 2512-2518 (in Russian). 18 1147. Field electron emission from tantalum covered with thin film of SiO and A1203. (Bulgaria) Using the probe method in a field electron emission microscope, emission properties of tantalum covered with adsorbed films of SiO and A1203 are investigated. Work function of the whole emitting surface is determined. It is concluded that the dielectric film produces widening of the barrier for electrons emitted from metal. K Bobev and Z Mireva, Rep of Inst of Electronics of Bulg Acad of Scienc, No 7, 1974, 1l-17 (in Bulgarian). 18 1148. Spectral dependence of exit depth of photoelectrons from (Cs, Rb),Sb. (Bulgaria) The relation between the excitation energy and effective free path of photoelectrons in (Cs, Rb)$b is investigated. It is found that maximum exit depth occurs at photo-emission threshold and it decreases
with excitation
energy increase. It is noted that large exit depth of
500 nm of photoelectrons from (Cs, Rb)$b results in high integral sensitivity of this photocathode in comparison with Cs,Sb. K Nanev et al, Rep of Inst of Electron of Buig Acad of Scienc, No 7, 1974, 19-22 (in Bulgarian). I8 1149. Experimental investigation of electron loss and capture by fast unexcited and metastable helium-like ions in ion-atomic collisions.
(USSR) The average cross sections for loss or capture of one to two electrons are determined in a mass-spectrometric apparatus for beams of helium-like particles containing a metastable component, produced by passage of cyclotron-accelerated B’ +, B2+, C3+ and N6+ ions through gas target or a thin celluloid film. I S Dmitriev et al, Zh Eksper Teor Fiz, 67 (6), 1974. 2047-2063 (in Russian). 1150.
Solitary
charge
density
waves
in a magnetoactive
18 plasma.
(USSR) It is shown that a charge density wave moving obliquely to a magnetic field may have the shape of a solitary electron bunch (charge density sol&on). The experiments were performed in a cylindrical plasma waveguide filled with argon to a pressure of 1 x 10e4 to 5 x lo-“ torr. Plasma was produced by collisions with electrons emitted from a hot cathode. S M Krivoruchko et al, Zh Eksper Teor Fir, 67 (6), 1974, 2092-2103 (in Russian). 18 1151. Mass-spectrometric investigation of the photoionization processes of tetranitromethane and its baloide derivatives. (USSR) Using a photoionization mass spectrometer, primary photoionization process in tetranitromethane and its haloide derivatives are investi-
gated in the energy interval of 11 to 14 eV. It is found that NO+ and NOz+ ions are formed as a result of dissociative photoionization of molecules. V K Potapov et al, Khim Vysok Energiy, 8 (3), 1974, 286287 (in Russian). 1152. Photoelectron emission from aromatic charge-transfer -caesium. (USSR)
18 complexes
Variations in spectral dependence of quantum yield of photoelectron emission from aromatic charge-transfer complexes at deposition of caesium on their surface are investigated in a vacuum ofm10-8 torr. V V Aleksandrov et al, Izv AN Latv SSR Ser Fiz Tekh Nauk. No 2. 1974, 114-l 17 (in Russian). 1153. Axial variations in characteristics of discharge hollow cathode in helium and argon. (USSR)
18 in magnesium
Using the method of probes, axial variations in characteristics of discharge in magnesium hollow cathode in helium and argon are measured. Measurements were performed at pressures ranging from 6 x 10mz to 3 torr. F Kidrasov et al, Vestn Mosk 232-235 (in Russian).
Univ
Fiz Astronom,
15 (2),
1974,
18 1154. Investigation of radial distribution of concentration of charged particles and potentila in column of glow discharge in CO, and water vapour. (USSR)
Using a method of single probe, radial distribution of concentration of positive ions and potential in column of glow discharge in CO1 and water vapour is measured in the pressure range of 0.5 to 2 torr and currents of 1 to 5 mA. A I Mksimov and V F Sokolov, Zh Tekh Fiz, 44 (lo), 1974, 2198-2202 (in Russian). I8 1155. High-frequency modulation of atomic particle beams in active corpuscular diagnostics of plasma. (USSR)
A proton beam with IO4 eV energy was modulated with lo6 Hz frequency and used for probing of dense plasma formations. Modulation of the beam was performed with the aid of a charge-exchange gas target. P A Demchenko et al., Zh Tekh Fir, 44 (lo), 1974. 2203-2210 (in Russian). 393