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248. Electromagnetic separation of short-lived isotopes of radon, xenon and krypton
Classified abstracts 235-248
for broad-band amplification of pulse signals and electron-optical devices with analogue conversion of the optical image are briefly described. Yu A Akimov and A B Fromberg, Izmerit Tekh, No 3, March 1972, 3-5 (in Russian). 31 235. Influence of electrode material on the life of impulse quartz tubular lamps. (USSR) Behaviour of impulse quartz tubular lamps with electrodes of tungsten, zinc amalgam and cadmium amalgam is studied during their life. The lamps are filled with xenon to pressure of 300 torr. Invar lead-ins are sealed to the quartz envelope by epoxy resin. Yu A Martsinkovskiy, Optiko Mekh Prom, 39 (3), March 1972, 59-61 (in Russian). 31 236. Secondary electron multiplier for mass spectrometer type MI-1305. (USSR) A secondary electron multiplier with an internal voltage divider and dynodes of CufBe alloy, for mass spectrometer type MI-1305, is described. Application of the electron multiplier resulted in an increase of sensitivity of the mass spectrometer by two orders of magnitude. The multiplier can also be used for the detection of negative ions. V G Ustinov and V I Sbvachko, Prib Tekh Eksper, No 1, Jan-Feb 1972, 236-237 (in Russian). 31 237. Characteristics of spiral channel multipliers. (USSR) Performance of spiral channel multipliers of high-lead glass as detectors of electrons with energies of 5 to 10 keV is explored in a vacuum system at 2 x 1Om6 torr. Current and counting characteristics are measured. The background counting rate was 0.3 to 2 pulses/s at an accelerating voltage of 3 kV. The output pulse duration is 0.3 ps. N A Krasilnikova et al, Prib Tekh Eksper. No 1, Jan-Feb 1972, 16% 169 (in Russian). 31 238. Coaxial impulse lamp for excitation of organic dye solutions. (USSR) Construction of a coaxial impulse lamp filled with xenon to pressure of 10-l 5 torr is described. The lamp enables one to obtain intensive light pulses with duration of 0.40% ps. M I Dzvubenko et al. Prib Tekh Eksoer. _, No 1. Jan-Feb 1972. 171173 (in Lion). ’ 31 239. New trends in the development of x-my intensifiers. (Czechoslovakia) A new x-ray image intensifier with the input image diameter of 270 mm is briefly described. Good results are obtained with a luminescent screen prepared by vacuum evaporation of CsI activated by Na. J Boleslav et al, Slubopr Obzor, 33 (l), Jan 1972, 51-52 (in Czech). 31 240. Photoelectron multiplier for operation at elevated temperature. I
(Czechoslovakia)
A vacuum photoelectron multiplier for operation at temperatures above 100°C is described. A B&alkali photocathode SbNaK, is used. J Raus, Slabopr Obzor, 33 (l), Jan 1972, 52-53 (in Czech). 31 241. Optimum pick-up tube. (Czechoslovakia) Parameters of vacuum television pick-up tubes such as the superorthicon, vidicon, plumbicon and epicon are discussed. The importance of suitable vacuum technology in their fabrication is stressed. J Prchlik and B Gadzuk, Slabopr Obzor, 33 (l), Jan 1972, 40-44 (in Czech). 31 242. Determining the noise spectrum in a backward-wave oscillator. (Czechoslovakia)
A description of the basic processes occurring in the electron beam and the determination of the character of the noise spectrum in a backward-wave oscillator is presented. Noise sources due to emission properties of cathode, velocity distribution of electrons, interaction of electron beam with residual gas, secondary electron emission from electron-gun electrodes, are considered. The method of the balance mixer for measurement of the signal/noise ratio of backward wave oscillator is described in detail. Experimental results on the noise properties of the oscillator are presented. J Ruzicka, SIubopr Obzor, 33 (l), Jan 1972, 9-13 (in Czech).
31 243. Photoconductive
television
pick-up tubes. (Czechoslovakia)
The spectral and gamma factor characteristics of Sb2S3, PbO and Si photoconductive targets in vacuum television pick-up tubes are presented. Preparation of Sb,S, targets in an evaporation apparatus is described. The thin film of Sb,S, is evaporated in vacuum at 10e5 torr on a transparent signal electrode of SnOa on glass. A second porous Sb,S, layer is deposited by evaporation in argon at pressure of 1 torr. Finally, a third layer of Sb,S, is evaporated again in vacuum at 10e5 torr. The target is sealed to the glass envelope of the tube with the aid of an indium gasket. Vacuum tightness is provided by an araldite sealing compound. Preparation of the mesh placed before the target is also described. M Jedlicka, Slubopr Obzor, 33 (l), Jan 1972, 21-28 (in Czech). 31 244. A directly-heated cathode. (USSR) A directly-heated cathode differing from the ordinary type in that its working section and current rings are made of a single piece of metal is described. The working surface is divided up into polygonal cells, and the areas of the cells diminish on passing from the middle of the working surface towards the current-carrying rings at the ends. In this way the surface temperature is equalized over the whole of the working section. A cathode of this type has better emission and a greater mechanical strength than its predecessors. V F Ioffe et al, USSR Patent No 260748, appl4th June 1968, publd 27th Jan 1972. 32. NUCLEONICS 245. Improvement of vacuum in bench-type charged particle accelerators. (USSR)
vacuum
systems
32 using
The possibility of utilizing the high-energy beams from charged particle accelerators for improvement of the vacuum conditions in experimental bench vacuum systems is investigated. The dependences of the specific rate of sputtering and evaporation of a titanium target on the current density and specific power of an accelerated beam of Bi + and Xe+ ions are calculated. Experimental verification was performed in a bench vacuum system, 1 m diameter and 10 m long. It is found that application to the Ti target of a beam of accelerated Bi+ ions with the current density 100 mA/cm2. and total current of l-3 A, resulted in an additional pumping speed of lo4 litres/sec and a pressure decrease from 7.6 x 10e5 to 2.6 x 10m5 torr. Similar experiments have been performed with a Xe+ ion accelerator in a laboratory system with volume of 1 m3. V G Pankratov et al. Prib Tekh Eksper, _, No 1. Jan-Feb 1972. 149-151 (in Russian). 32 246. Experiments on ultra-high frequency heating of plasma in the TUMAN-2 machine. (USSR) Experiments on ultra-high frequency
heating of plasma in the toroidal
magnetic container TUMAN-2 have been performed at higher hybrid frequencies. The system was evacuated to 5 x lo-’ torr and then filled with hydrogen to pressure of 10m4 to 10m3 torr. Efficiencies of several tens of per cent of ultra-high frequency energy introduction into the plasma were obtained. V E Golant et al, Zh Tekh Fiz, 42 (3), March 1972, 620-628 (in Russian). 32 247. Causes of the appearance of electronic load in the accelerator tubes of electrostatic accelerators. (USSR) It is experimentally shown that conductivity in vacuum insulation can arise due to emission patches formed on surface of the cathode electrode under the action of discharge phenomena. The formation of leakage currents (electronic load) in accelerator tubes is caused by the presence of contaminating dielectric films capable of electron emission in electric fields of about lo4 V/cm. F G Zheleznikov et al, Prib Tekh Eksper, No 1, Jan-Feb 1972, 41-43 (in Russian). 32 248. Electromagnetic separation of short-lived isotopes of radon, xenon and krypton. (USSR) The method of electromagnetic separation of short-lived isotopes of Rn, Xe and Kr is presented. The mass separator inlet system containing an oil throughput meter, needle valves, furnace and discharge chamber is described. V P Afansev et al, Prib Tekh Eksper, No 1, Jan-Feb 1972, 4547 (in Russian). 115
for broad-band amplification of pulse signals and electron-optical devices with analogue conversion of the optical image are briefly described. Yu A Akimov and A B Fromberg, Izmerit Tekh, No 3, March 1972, 3-5 (in Russian). 31 235. Influence of electrode material on the life of impulse quartz tubular lamps. (USSR) Behaviour of impulse quartz tubular lamps with electrodes of tungsten, zinc amalgam and cadmium amalgam is studied during their life. The lamps are filled with xenon to pressure of 300 torr. Invar lead-ins are sealed to the quartz envelope by epoxy resin. Yu A Martsinkovskiy, Optiko Mekh Prom, 39 (3), March 1972, 59-61 (in Russian). 31 236. Secondary electron multiplier for mass spectrometer type MI-1305. (USSR) A secondary electron multiplier with an internal voltage divider and dynodes of CufBe alloy, for mass spectrometer type MI-1305, is described. Application of the electron multiplier resulted in an increase of sensitivity of the mass spectrometer by two orders of magnitude. The multiplier can also be used for the detection of negative ions. V G Ustinov and V I Sbvachko, Prib Tekh Eksper, No 1, Jan-Feb 1972, 236-237 (in Russian). 31 237. Characteristics of spiral channel multipliers. (USSR) Performance of spiral channel multipliers of high-lead glass as detectors of electrons with energies of 5 to 10 keV is explored in a vacuum system at 2 x 1Om6 torr. Current and counting characteristics are measured. The background counting rate was 0.3 to 2 pulses/s at an accelerating voltage of 3 kV. The output pulse duration is 0.3 ps. N A Krasilnikova et al, Prib Tekh Eksper. No 1, Jan-Feb 1972, 16% 169 (in Russian). 31 238. Coaxial impulse lamp for excitation of organic dye solutions. (USSR) Construction of a coaxial impulse lamp filled with xenon to pressure of 10-l 5 torr is described. The lamp enables one to obtain intensive light pulses with duration of 0.40% ps. M I Dzvubenko et al. Prib Tekh Eksoer. _, No 1. Jan-Feb 1972. 171173 (in Lion). ’ 31 239. New trends in the development of x-my intensifiers. (Czechoslovakia) A new x-ray image intensifier with the input image diameter of 270 mm is briefly described. Good results are obtained with a luminescent screen prepared by vacuum evaporation of CsI activated by Na. J Boleslav et al, Slubopr Obzor, 33 (l), Jan 1972, 51-52 (in Czech). 31 240. Photoelectron multiplier for operation at elevated temperature. I
(Czechoslovakia)
A vacuum photoelectron multiplier for operation at temperatures above 100°C is described. A B&alkali photocathode SbNaK, is used. J Raus, Slabopr Obzor, 33 (l), Jan 1972, 52-53 (in Czech). 31 241. Optimum pick-up tube. (Czechoslovakia) Parameters of vacuum television pick-up tubes such as the superorthicon, vidicon, plumbicon and epicon are discussed. The importance of suitable vacuum technology in their fabrication is stressed. J Prchlik and B Gadzuk, Slabopr Obzor, 33 (l), Jan 1972, 40-44 (in Czech). 31 242. Determining the noise spectrum in a backward-wave oscillator. (Czechoslovakia)
A description of the basic processes occurring in the electron beam and the determination of the character of the noise spectrum in a backward-wave oscillator is presented. Noise sources due to emission properties of cathode, velocity distribution of electrons, interaction of electron beam with residual gas, secondary electron emission from electron-gun electrodes, are considered. The method of the balance mixer for measurement of the signal/noise ratio of backward wave oscillator is described in detail. Experimental results on the noise properties of the oscillator are presented. J Ruzicka, SIubopr Obzor, 33 (l), Jan 1972, 9-13 (in Czech).
31 243. Photoconductive
television
pick-up tubes. (Czechoslovakia)
The spectral and gamma factor characteristics of Sb2S3, PbO and Si photoconductive targets in vacuum television pick-up tubes are presented. Preparation of Sb,S, targets in an evaporation apparatus is described. The thin film of Sb,S, is evaporated in vacuum at 10e5 torr on a transparent signal electrode of SnOa on glass. A second porous Sb,S, layer is deposited by evaporation in argon at pressure of 1 torr. Finally, a third layer of Sb,S, is evaporated again in vacuum at 10e5 torr. The target is sealed to the glass envelope of the tube with the aid of an indium gasket. Vacuum tightness is provided by an araldite sealing compound. Preparation of the mesh placed before the target is also described. M Jedlicka, Slubopr Obzor, 33 (l), Jan 1972, 21-28 (in Czech). 31 244. A directly-heated cathode. (USSR) A directly-heated cathode differing from the ordinary type in that its working section and current rings are made of a single piece of metal is described. The working surface is divided up into polygonal cells, and the areas of the cells diminish on passing from the middle of the working surface towards the current-carrying rings at the ends. In this way the surface temperature is equalized over the whole of the working section. A cathode of this type has better emission and a greater mechanical strength than its predecessors. V F Ioffe et al, USSR Patent No 260748, appl4th June 1968, publd 27th Jan 1972. 32. NUCLEONICS 245. Improvement of vacuum in bench-type charged particle accelerators. (USSR)
vacuum
systems
32 using
The possibility of utilizing the high-energy beams from charged particle accelerators for improvement of the vacuum conditions in experimental bench vacuum systems is investigated. The dependences of the specific rate of sputtering and evaporation of a titanium target on the current density and specific power of an accelerated beam of Bi + and Xe+ ions are calculated. Experimental verification was performed in a bench vacuum system, 1 m diameter and 10 m long. It is found that application to the Ti target of a beam of accelerated Bi+ ions with the current density 100 mA/cm2. and total current of l-3 A, resulted in an additional pumping speed of lo4 litres/sec and a pressure decrease from 7.6 x 10e5 to 2.6 x 10m5 torr. Similar experiments have been performed with a Xe+ ion accelerator in a laboratory system with volume of 1 m3. V G Pankratov et al. Prib Tekh Eksper, _, No 1. Jan-Feb 1972. 149-151 (in Russian). 32 246. Experiments on ultra-high frequency heating of plasma in the TUMAN-2 machine. (USSR) Experiments on ultra-high frequency
heating of plasma in the toroidal
magnetic container TUMAN-2 have been performed at higher hybrid frequencies. The system was evacuated to 5 x lo-’ torr and then filled with hydrogen to pressure of 10m4 to 10m3 torr. Efficiencies of several tens of per cent of ultra-high frequency energy introduction into the plasma were obtained. V E Golant et al, Zh Tekh Fiz, 42 (3), March 1972, 620-628 (in Russian). 32 247. Causes of the appearance of electronic load in the accelerator tubes of electrostatic accelerators. (USSR) It is experimentally shown that conductivity in vacuum insulation can arise due to emission patches formed on surface of the cathode electrode under the action of discharge phenomena. The formation of leakage currents (electronic load) in accelerator tubes is caused by the presence of contaminating dielectric films capable of electron emission in electric fields of about lo4 V/cm. F G Zheleznikov et al, Prib Tekh Eksper, No 1, Jan-Feb 1972, 41-43 (in Russian). 32 248. Electromagnetic separation of short-lived isotopes of radon, xenon and krypton. (USSR) The method of electromagnetic separation of short-lived isotopes of Rn, Xe and Kr is presented. The mass separator inlet system containing an oil throughput meter, needle valves, furnace and discharge chamber is described. V P Afansev et al, Prib Tekh Eksper, No 1, Jan-Feb 1972, 4547 (in Russian). 115