1663. Solution of the Laplace equation for the Penning discharge

1663. Solution of the Laplace equation for the Penning discharge

Classified abstracts 1649--1665 The adsorption of Ha and O~ on the surface of a W tip formed at a high temperature under the influence of a high volta...

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Classified abstracts 1649--1665 The adsorption of Ha and O~ on the surface of a W tip formed at a high temperature under the influence of a high voltage was studied in an all-glass apparatus at pressures of I × 10-9 and 5 × 10-~9 torr. At 78°K even the adsorption heat of O2 is not sufficient for the surface layers of W to be rearranged. (Czechoslovakia) Z Knor and D Lazarov, Czech J Phys, BI6 (4), 1966, 333-337 (in

English). 16 1649. Helium passage through glasses. (USSR) The passage of He through 12 types of glasses usually used in vacuum technique (all Soviet made) and its dependence on the temperature was studied and measured values are given. It is shown that aluminosilicate glasses are the most suitable ones for UHV. Also it was observed that He passage rises for glasses with the higher percentage contents of SiO2q-B=O3 component. (USSR) G A Vostrov and O I Boishakov, Pribory Tekh Eksp, 11 (2), Mar-Apt

1966, 112-116 (in Russian).

A P Ovchinnikov and B M Tsarev, Fiz Tverd Tela, 8 (5), May 1966,

1493-1497 (in Russian). 18 " 16 1656. Emission and adsorption characteristics of the W-La system.

(USSR) The behaviour of La films on tungsten was studied and it was found that the optimal work function is 2.2 eV and average energy of evaporation of La from W is 5.1 eV. Optimal temperatures for the W-La cathode are 1400--1800°K. (USSR) N A Gurbatyi and S Khasimova, Fiz Tverd Tela, 8 (5), May 1966,

1440-1448 (in Russian). 18 : 33 1657. Investigation of breakdown traces in systems with an oxide cathode. ( USSR ) Experiments showed that vacuum breakdown in pressures of 10-410-7 torr in oxide cathodes is probably initiated by field-emission.

(USSR) P V Poshekhonov et al, Radiotekh Elektron, 11 (5), May 1966,

886-893 (in Russian).

17. Thermodynamics

18 : 32 Study of an induction-type conical plasma source. See abstract number 1805. 18 : 33 1651. New finding in the field of the oxide coated cathode emission.

18 : 33 1658. Effective extraction of electrons from a modified Penning discharge. ( USSR ) The efficacy of a Penning discharge as an electron source was studied. It is shown that some magnetic and electric field non-homogenities make this method usable in practice. Experiments were performed in the pressure range 10-2-10 -5 tort. (USSR) Yu E Kreindel, Zh Tekh Fiz, 36 (5), 903-906 (in Russian). 18 1659. Study of germanium emission properties on different faces of tungsten single crystal. (USSR) It was found that semiconductor effects occur only in small definite areas of the Ge layer. (USSR) N V Mileshkina et al, Fiz Tverd Tela, 8 (5), May 1966, 1390-1393

17

1650. Thermodynamic studies by mass spectrometry. (Belgium) Uranium vapour pressure and partial pressure of uranium, UO and UO2 molecules in the system Uq-UO= (S) were measured by mass spectrometry. A Pattoret et al, Brussels University, 1965, 60 pages (in French).

18. Gaseous electronics

(Germany)

(in Russian).

There is no theory of the oxide coated cathode which gives a sufficient explanation of the electron-emission under various conditions. In the present work a dynamic model is suggested in order to explain the principle mechanisms inside the oxide layer and the interaction between oxide layer and vacuum. This model gives good agreement with experimental results and unexplained contradictions of earlier theories are eliminated. For further research on oxide cathodes, this model could serve as a useful starting point. K M Tischer, Vakuum-Technik, 15, May 1966, 114-122 (in German.) 18 1652. Investigation of electric arcs under conditions of weightlessness.

18 1660. Remarks on interpretation of the emission of sandwich cathodes. A method of calculating the emission current of sandwich cathodes is discussed. (Czechoslovakia) L Eckertova, Czech J Phys, BI6 (4), 1966, 358-361 (in English). 18 1661. Emission properties of the alloys Pt-La, Ir-La, Os-La. (USSR) Values of work function and secondary electron emission coefficient are given. (USSR) E V Vasflyeva et al, Radiotekh Elektron, 11 (6), June 1966, 1150-1151,

(Germany)

(in Russian).

Characteristics of electric arcs under dc and ac running condition and also after switching on have been studied in air, nitrogen, argon, and carbon dioxide. Results have been compared with theoretical calculation.

18 1662. Emission properties of the alloys Pt-Th, Ir-Th, Os--Th and

W Ebert, Beitr Plasma Physik, 5, 1965, 371-376 (in German). 18 1653. Research on electrical breakdown in vacuum at Laboratorio Gas Ionizatti. (Italy) A review is made of the theories of breakdown in vacuum and an experiment is described in which electron breakdown currents are prevented from reaching the anode by means of a transverse magnetic field. C Gourlan et al, Comitato Nazionale per L'Energia Nucleare,

Frascati, Italy. 18 : 16 1654. Adsorption and electron emission of alkaline earth metal films on tungsten iridium and rhodium. (USSR) This paper reports a study of electron emission of Ba on W, Sr on W, Ca on W, Ba on Ir, Ca on Ir and Ba on Rh films in the electron projector with total pressure better than 10-9 torT. Adsorption of these alkaline earth metals and their mixtures on W, Ir and Rh was also studied and the results are discussed. (USSR) V I Makuldm and B M Tsarev, Fiz Tverd Tela, 8 (5), May 1966,

1417-1427 (in Russian). 18 : 16 • 33 1655. Caesium adsorption on faces of tungsten single crystals. (USSR) The design of an electron projector with a rotating tip for study of the adsorption of Cs on W and the work function of this system is described and results are presented. The work function is about 1.5 eV and the energy of adsorption is about 1.75 eV. (USSR)

506

(Czechoslovakia)

Re-Th.

(USSR)

Values of work function and secondary electron emission coefficient are given. (USSR) B Ch Dyubua et al, Radiotekh Elektron, 11 (6), June 1966, 1149-1150

(in Russian). 18 1663. Solution of the Laplace equation for the Penning discharge.

(USSR) A method for solution of the Laplace equation for the potential at any point in the interelectrode space is given. By using some approximations the calculation is simple and has high accuracy.

(USSR) T I Ivanova et al, Zh Tekh Fiz, 36 (5), May 1966, 907-912 (in Russian). 18 1664. The present state of the theory of secondary electron emission.

(Czechoslovakia) This report gives a brief explanation of the mechanism and the modern quanttma theory of secondary emission from metals.

(Czechoslovakia) V Malat, Czech JPhys, A16 (3), May 1966, 242-250 (in Czech). 18 1665. A contribution to the theory of ionization waves in the positive column of a glow discharge. (Czechoslovakia) Normalizing of the Boltzmann-Vlasov kinetic equation is performed for small discharge currents (up to 10 mA. cm -=) in a one-dimensional approximation on the assumption that the velocity distribution of the electrons is near to Maxwell distribution. (Czechoslovakia) K Kolacek, Czech J Phys, A16 (3), May 1966, 221-227 (in Czech).