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Effect of crystal lattice thermal vibrations on ion-electron emission coefficient
Classified
abstracts
293-308
secondary electron emission, the primary electron non-elastic reflection and the secondary electrons energy distribution, was studied. L A Ermolaev and B Kh Dvubua. Radiotekh Elektron. , 11 (91. ,,, Scot . 1966, 1724-1728
(in Russian>.
’
18 293. Positive column of helium discharge in a strong magnetic field. (USSR)
The transformation of a He discharge positive column from a laminar convection regime into a turbulent one and the turbulent regime structure were investigated. A V Nedospasov and S S Sobolev, Zh Tekh Fiz, 36 (IO), Ott 1966, 1758-l 767 (in Russian)
. 18
decay of discharge plasma with oscillating electrons in a strong magnetic field. (USSR) Presumably the causes of the anomalous quick decay of discharge plasma in a magnetic field with intensity higher than 10%Oe are the macroscopic turbulence and hf oscillation of plasma. The magnetic field critical values as a function of the pressure in the lOmato 10-l torr range are given. V G Grigorenko, Zh Tekh Fiz, 36 (lo), Ott 1966, 1800-1807 (in 294. Anomalous
Russian). 295. Ions mobility in own gas.
18 (USSR)
Equations for ion drift velocity in own gas are derived and calculated values are compared with those measured by other authors. B M Smimov, Zh Tekh Fiz, 36 (IO), Ott 1966,1864-1871 (in Russian). 18 : 31 2%. Influence of electrode material on the delay tbne of discharge at electrical breakdown in a vacuum gap. (USSR) An equation for the breakdown delay time is established. Satisfactory
calculations of these values are obtained for vacuum gaps wider than .02 inches, for narrower gaps the calculation may be used as a rough approximation. The influence of the residual gas pressure was not investigated. G M Kasslrov, Zh Tekh Fiz, 36 (IO), Ott 1966, 1883-1885 (in
301. Investigation of transmission secondary-electron emitters.
18 :30
(USSR) The preparation of transmission secondary-electron emitters is described. These consist of an A&O, grid or thin layer as a backing, Al intermediate layer and one or more secondary-emission layers of vacuum evaporated MgO or KCl. The best results were obtained with the porous KC1 layer of thickness 24 pm as an emitter (gain about 35 at 7 kV and at backing layer transparency 70 per cent). T Reichel and V Jares. Radiotekh Elektron. 11 (IO). Ott 1966. 18321836 (in Russian). 18 302. Charged particle flow to the cathode in a Penning type discharge. (USSR)
The direction and energy of the ions deposited on the centre of the cathode as a function of the magnetic field intensity, anode voltage and the pressure in the 1O-5 to 10d4 torr range were measured. GV Smirnitskaya and R. P Babertsyan, Radiotekh Elektron, 11 (IO), Ott 1966, 1897-1899
(in Russian).
18 volt-ampere characteristics of the leakage and emission current of sandwich cathodes. (Czechoslovakia) The influence of the thickness of the dielectric on the electrical properties of cathodes was investigated. Two different dielectrics (oxide and evaporated layers) were used, but no great difference was observed. V Balas, Czech J Phys, section B, 16 (7)) 1966, 569-577 (in English). 303. The
18
304. Ultrahigh vacuum apparatus for investigating film emission from a low-pressure mercury arc. (Germany)
The problems of pumping, wall materials and pressure measurement in ultrahigh vacuum apparatus (lo-’ to lo-@ torr) are discussed. The apparatus would be equally suitable for studying other problems of gas discharge physics. J Mitterauer, Elektrotech Maschinenbau, 83 (5), 1966, 308-311 (in German).
Russian). 18 297. Properties of a microwave discharge near plasma resonance. (USSR) The rapid increase of the 4713 A line intensity in a He discharge at
3 kMc was investigated. This effect is caused by changing the helium plasma resonance frequency at higher absorbed powers. A I Maksimov. Zh Tekh Fiz. 36 (IO). Ott 1966. 1894-1896 fin .., Russian).
18
298. Investigation of the speed of plasma extension at current break in
vacuum. (USSR) The speed of the plasma extension in a vacuum switch after breaking the dc current (30 to 1,000 A) was investigated. The speed of the plasma front is about 5 times higher than the speed of plasma during subsequent plasma arcing. MA Tyulina,Zh Tekh Fiz, 36 (IO), Ott 1966,1095-1908 (in Russian). 18 299. Excitation by Znd-ordercollisions in the radiation of N, and CO molecular hands from N,+ Ar, CO+ Ar mixtures in a glow discharge. (USSR) Mixtures argon and N, or CO with total pressures of 2 torr and N, or CO partial pressures of 0.02 to 1.98 torr, were prepared and subjected to a glow discharge. The influence of molecular bands corresponding to Znd-order collision excitation for the given partial pressures of N, and CO were determined and compared to calculated values. L A Chemenko, Zzv VUZ Fit, 9 (5)) 1966, 67-70 (in Russian). 18 300. Effect of crystal lattice thermal vibrations on ion-electron emission coe5cient. (USSR) The influence of temperature of Cu backing and of the angle of inci-
dence of bombarding ions on the ion-electron emission coefficient was investigated. Backings of Cu polycrystal and (110) and (111) faces of Cu single crystal were employed at temperatures 200 and 900°C bombarded by Ne, Ar and Kr ions with energies 30 keV. The effect of temperature was observed only on single crystal backings. I N Evdokimov et al, Fir Tverd Tela, 8 (ZO), Ott 1966, 2939-2944 (in Russian).
II. Vacuum apparatus and auxiliaries 20. Pumping
systems
20 305. The vacuum system of the MM II experiment. The MM II experimental assembly at Fontenay-aux-Roses was pumped down by a combination of oil diffusion pumps and titanium evaporation pumps on cold surfaces. New and larger equipment is being installed, aimed at providing a total pumping speed in excess of 106 litres/second. This vacuum system, the previous one, associated technical problems and some results of measurements are described. 2 Sledziewski and F Prevot, Euratom Information, 4 (IO), 1966, 1107, Rept (MF)
EUR 31OOe.
20 306. Vacuum furnace for high temperature fractural studies. (USA) An inexpensive vacuum furnace was constructed to study the high
temperature fracture of ceramic materials and was designed for use with an Instron testing machine. The vacuum chamber used is described and diagrams given. P L Gutshall and G D Swanson, Rev Sci Znstrum, 37,1966,1413-I414. 307. High vacuum aggregate HVAO-6/30/11.
20 (Germany)
The unit assembly described consists of a high vacuum oil diffusion pump with oil-vapour trap, programme valve, backing vacuum container and a magnetic backing pump valve. The pumping capacity is better than 30 litres/sec at lo-* torr. The pump is of the all-metal, three-stage fractionating type using oils with vapour pressure less than lo-’ torr at 25°C. Construction and operation of the various components are summarized. E Wagner and G Osterland, Jena Review, No 3, 1966, 185-186 (in English). 308. Laboratory vacuum furnace with exchange heating system. (Czechoslovakia)
20
Design details of a simple furnace, for vacuum annealing of Fe and other applications at lo-” torr in a chamber of volume 15 litres, are 111
abstracts
293-308
secondary electron emission, the primary electron non-elastic reflection and the secondary electrons energy distribution, was studied. L A Ermolaev and B Kh Dvubua. Radiotekh Elektron. , 11 (91. ,,, Scot . 1966, 1724-1728
(in Russian>.
’
18 293. Positive column of helium discharge in a strong magnetic field. (USSR)
The transformation of a He discharge positive column from a laminar convection regime into a turbulent one and the turbulent regime structure were investigated. A V Nedospasov and S S Sobolev, Zh Tekh Fiz, 36 (IO), Ott 1966, 1758-l 767 (in Russian)
. 18
decay of discharge plasma with oscillating electrons in a strong magnetic field. (USSR) Presumably the causes of the anomalous quick decay of discharge plasma in a magnetic field with intensity higher than 10%Oe are the macroscopic turbulence and hf oscillation of plasma. The magnetic field critical values as a function of the pressure in the lOmato 10-l torr range are given. V G Grigorenko, Zh Tekh Fiz, 36 (lo), Ott 1966, 1800-1807 (in 294. Anomalous
Russian). 295. Ions mobility in own gas.
18 (USSR)
Equations for ion drift velocity in own gas are derived and calculated values are compared with those measured by other authors. B M Smimov, Zh Tekh Fiz, 36 (IO), Ott 1966,1864-1871 (in Russian). 18 : 31 2%. Influence of electrode material on the delay tbne of discharge at electrical breakdown in a vacuum gap. (USSR) An equation for the breakdown delay time is established. Satisfactory
calculations of these values are obtained for vacuum gaps wider than .02 inches, for narrower gaps the calculation may be used as a rough approximation. The influence of the residual gas pressure was not investigated. G M Kasslrov, Zh Tekh Fiz, 36 (IO), Ott 1966, 1883-1885 (in
301. Investigation of transmission secondary-electron emitters.
18 :30
(USSR) The preparation of transmission secondary-electron emitters is described. These consist of an A&O, grid or thin layer as a backing, Al intermediate layer and one or more secondary-emission layers of vacuum evaporated MgO or KCl. The best results were obtained with the porous KC1 layer of thickness 24 pm as an emitter (gain about 35 at 7 kV and at backing layer transparency 70 per cent). T Reichel and V Jares. Radiotekh Elektron. 11 (IO). Ott 1966. 18321836 (in Russian). 18 302. Charged particle flow to the cathode in a Penning type discharge. (USSR)
The direction and energy of the ions deposited on the centre of the cathode as a function of the magnetic field intensity, anode voltage and the pressure in the 1O-5 to 10d4 torr range were measured. GV Smirnitskaya and R. P Babertsyan, Radiotekh Elektron, 11 (IO), Ott 1966, 1897-1899
(in Russian).
18 volt-ampere characteristics of the leakage and emission current of sandwich cathodes. (Czechoslovakia) The influence of the thickness of the dielectric on the electrical properties of cathodes was investigated. Two different dielectrics (oxide and evaporated layers) were used, but no great difference was observed. V Balas, Czech J Phys, section B, 16 (7)) 1966, 569-577 (in English). 303. The
18
304. Ultrahigh vacuum apparatus for investigating film emission from a low-pressure mercury arc. (Germany)
The problems of pumping, wall materials and pressure measurement in ultrahigh vacuum apparatus (lo-’ to lo-@ torr) are discussed. The apparatus would be equally suitable for studying other problems of gas discharge physics. J Mitterauer, Elektrotech Maschinenbau, 83 (5), 1966, 308-311 (in German).
Russian). 18 297. Properties of a microwave discharge near plasma resonance. (USSR) The rapid increase of the 4713 A line intensity in a He discharge at
3 kMc was investigated. This effect is caused by changing the helium plasma resonance frequency at higher absorbed powers. A I Maksimov. Zh Tekh Fiz. 36 (IO). Ott 1966. 1894-1896 fin .., Russian).
18
298. Investigation of the speed of plasma extension at current break in
vacuum. (USSR) The speed of the plasma extension in a vacuum switch after breaking the dc current (30 to 1,000 A) was investigated. The speed of the plasma front is about 5 times higher than the speed of plasma during subsequent plasma arcing. MA Tyulina,Zh Tekh Fiz, 36 (IO), Ott 1966,1095-1908 (in Russian). 18 299. Excitation by Znd-ordercollisions in the radiation of N, and CO molecular hands from N,+ Ar, CO+ Ar mixtures in a glow discharge. (USSR) Mixtures argon and N, or CO with total pressures of 2 torr and N, or CO partial pressures of 0.02 to 1.98 torr, were prepared and subjected to a glow discharge. The influence of molecular bands corresponding to Znd-order collision excitation for the given partial pressures of N, and CO were determined and compared to calculated values. L A Chemenko, Zzv VUZ Fit, 9 (5)) 1966, 67-70 (in Russian). 18 300. Effect of crystal lattice thermal vibrations on ion-electron emission coe5cient. (USSR) The influence of temperature of Cu backing and of the angle of inci-
dence of bombarding ions on the ion-electron emission coefficient was investigated. Backings of Cu polycrystal and (110) and (111) faces of Cu single crystal were employed at temperatures 200 and 900°C bombarded by Ne, Ar and Kr ions with energies 30 keV. The effect of temperature was observed only on single crystal backings. I N Evdokimov et al, Fir Tverd Tela, 8 (ZO), Ott 1966, 2939-2944 (in Russian).
II. Vacuum apparatus and auxiliaries 20. Pumping
systems
20 305. The vacuum system of the MM II experiment. The MM II experimental assembly at Fontenay-aux-Roses was pumped down by a combination of oil diffusion pumps and titanium evaporation pumps on cold surfaces. New and larger equipment is being installed, aimed at providing a total pumping speed in excess of 106 litres/second. This vacuum system, the previous one, associated technical problems and some results of measurements are described. 2 Sledziewski and F Prevot, Euratom Information, 4 (IO), 1966, 1107, Rept (MF)
EUR 31OOe.
20 306. Vacuum furnace for high temperature fractural studies. (USA) An inexpensive vacuum furnace was constructed to study the high
temperature fracture of ceramic materials and was designed for use with an Instron testing machine. The vacuum chamber used is described and diagrams given. P L Gutshall and G D Swanson, Rev Sci Znstrum, 37,1966,1413-I414. 307. High vacuum aggregate HVAO-6/30/11.
20 (Germany)
The unit assembly described consists of a high vacuum oil diffusion pump with oil-vapour trap, programme valve, backing vacuum container and a magnetic backing pump valve. The pumping capacity is better than 30 litres/sec at lo-* torr. The pump is of the all-metal, three-stage fractionating type using oils with vapour pressure less than lo-’ torr at 25°C. Construction and operation of the various components are summarized. E Wagner and G Osterland, Jena Review, No 3, 1966, 185-186 (in English). 308. Laboratory vacuum furnace with exchange heating system. (Czechoslovakia)
20
Design details of a simple furnace, for vacuum annealing of Fe and other applications at lo-” torr in a chamber of volume 15 litres, are 111