Hollow cathode discharge in low pressure oxygen: transient mode

Glow characteristics of the discharge with cylindrical hollow cathode at oxygen pressure in a range of 0.015…0.09 Torr are determined. Dependencies of radial electric field in the plasma on the discharge parameters are defined, and particular fact of creation at pressure higher than ~ 0.06 Torr the...

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Опубліковано в: :Вопросы атомной науки и техники
Дата:2015
Автори: Bazhenov, V.Yu., Matsevich, S.V., Piun, V.M., Tsiolko, V.V.
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Мова:Англійська
Опубліковано: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2015
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Цитувати:Hollow cathode discharge in low pressure oxygen: transient mode / V.Yu. Bazhenov, S.V. Matsevich, V.M. Piun, V.V. Tsiolko // Вопросы атомной науки и техники. — 2015. — № 4. — С. 177-180. — Бібліогр.: 18 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Bazhenov, V.Yu.
Matsevich, S.V.
Piun, V.M.
Tsiolko, V.V.
author_facet Bazhenov, V.Yu.
Matsevich, S.V.
Piun, V.M.
Tsiolko, V.V.
citation_txt Hollow cathode discharge in low pressure oxygen: transient mode / V.Yu. Bazhenov, S.V. Matsevich, V.M. Piun, V.V. Tsiolko // Вопросы атомной науки и техники. — 2015. — № 4. — С. 177-180. — Бібліогр.: 18 назв. — англ.
collection DSpace DC
container_title Вопросы атомной науки и техники
description Glow characteristics of the discharge with cylindrical hollow cathode at oxygen pressure in a range of 0.015…0.09 Torr are determined. Dependencies of radial electric field in the plasma on the discharge parameters are defined, and particular fact of creation at pressure higher than ~ 0.06 Torr the potential barrier at the boundary between negative glow plasma and cathode layer, which limits ion escaping to the cathode. As well, limits of the discharge glow characteristics are determined, which result in appearance of the hollow cathode effect. Встановлено характеристики горіння розряду з циліндричним порожнистим катодом при тисках кисню 0,015…0,09 Торр. Знайдено залежності радіального електричного поля в плазмі від параметрів розряду, зокрема, встановлено факт утворення при тисках більше ~ 0,06 Торр потенціального бар’єру на границі між плазмою негативного світіння та катодним шаром, який обмежує вихід іонів на катод. Також встановлено граничні характеристики горіння розряду, при яких починає проявлятися ефект порожнистого катодa. Установлены характеристики горения разряда с цилиндрическим полым катодом при давлениях кислорода 0,015…0,09 Торр. Найдены зависимости радиального электрического поля в плазме от параметров разряда, в частности, установлен факт образования при давлениях больше ~ 0,06 Торр потенциального барьера на границе между плазмой отрицательного свечения и катодным слоем, ограничивающего уход ионов на катод. Также установлены граничные ха-рактеристики горения разряда, при которых начинает проявляться эффект полого катода.
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fulltext ISSN 1562-6016. ВАНТ. 2015. №4(98) 177 HOLLOW CATHODE DISCHARGE IN LOW PRESSURE OXYGEN: TRANSIENT MODE V.Yu. Bazhenov, S.V. Matsevich, V.M. Piun, V.V. Tsiolko Institute of Physics NASU, Kiev, Ukraine E-mail: matsevich@gmail .com Glow characteristics of the discharge with cylindrical hollow cathode at oxygen pressure in a range of 0.015…0.09 Torr are determined. Dependencies of radial electric field in the plasma on the discharge parameters are defined, and particular fact of creation at pressure higher than ~ 0.06 Torr the potential barrier at the boundary be- tween negative glow plasma and cathode layer, which limits ion escaping to the cathode. As well, limits of the dis- charge glow characteristics are determined, which result in appearance of the hollow cathode effect. PACS: 52.80.-s, 52.25.Ya INTRODUCTION Hollow cathode discharge phenomenon was described in scientific literature yet in 1916 by Paschen at the studies of helium emission spectra – substitution of flat cathode by hollow cylinder shaped one resulted in es- sential growth of the discharge current under the same discharge voltage [1]. In subsequent decades hollow cathode discharge (HCD) was widely used in atomic absorption and emission spectroscopy [2] due to its abil- ity to generate intense ligh emission in wavelength range fom vacuum ultraviolet till near infrared. Later, along with other discharge types, HCD found its usage in plasma-technological applications [3], particularly, for low temperature deposition of hydrogenated amorphous silicon material, a-Si:H [4], for modification of the sur- face of Ti implants by the production of rough surfaces that consist of a mixture of Ti-oxides [5] and so on. It should be noted at once that in the literature (e.g. see [6]) all hollow cathode discharge appearances are conditionally subdivided into three types: glow, high voltage, and arc ones. Everyone oh those discharge pos- sesses its own peculiarities. In the following, only glow discharge type will be considered. The most common criterion of hollow cathode dis- charge is a requirement that transverse dimension of the cathode cavity should be comparable with those of the discharge cathode regions, such as cathode layer and glow plasma ([6], p. 6). When cathode transverse di- mension is considerably less than those of the discharge cathode regions, fast electrons accelerated in the cath- ode layer can undergo essential number of oscillations in the negative glow plasma before spending practically total their energy for gas ionization and excitation, and their coming to the discharge anode due scattering at the gas atoms/molecules. With the use of cylindrical cath- ode shape, plasma density at the cathode axis also in- creases due to “ballistic” focusing of fast electrons. The literature devoted to study of hollow cathode discharges is rather extensive (e.g. see [6 - 12] and ref- erences therein). However, practically all researches were accomplished with the use of noble gases as work- ing media. Usage of molecular gases, particularly, elec- tronegative ones, was a rare event [13, 14], although it is known that negative ions essentially influence the plasma features. Besides, the researches were usually performed at high enough pressure values (a couple of Torr and above) using hollow cathodes of small radius (several millimeters). These circumstances limited pos- sibilities of correct determining plasma parameters in such discharge. Particularly, it regards determining the cathode layer thickness (that is, the discharge region with high electric field strength). Usually, it was as- sumed that the cathode layer boundary coincides with one between the dark space and the negative glow. It is not totally correct, since the negative glow consists of two parts: one of those fills a portion of the cathode layer, whereas another one belongs to the plasma (plas- ma part of the negative glow) [15, 16]. As it was already noted above, the hollow cathode effect occurs when the hollow cathode transverse di- mension is less than the discharge glow length. In the opposite case, the discharge behavior is practically iden- tical to usual short (that is, without positive column) discharge with flat cathode. Purpose of the present work is the study of peculiari- ties of hollow cathode discharge with large dimensions (tens centimeters) at oxygen pressure lower than 0.1 Torr, particularly, those regarding the discharge transition from flat cathode operation mode to that with realization of the hollow cathode effect. 1. EXPERIMENT SET-UP AND MEASUREMENTS The discharge hollow cathode was elaborated from stainless steel and had the following dimensions: 38 cm diameter and 42 cm length (the cathode simultaneously served as vacuum chamber). The discharge made of copper having 30.5 cm diameter was located near back side of the cathode/chamber. From another side, the cathode cavity was closed by a door with transparent window having 280 mm diameter. An advantage of copper anode was the fact that the resistance value of oxide layer formed at the anode surface during its op- eration in oxygen had practically no effect on the plas- ma parameters. Use of the anode with large dimension (comparable with the cathode diameter) enabled obtain- ing high longitudinal uniformity of the plasma. With such anode, longitudinal uniformity of the plasma densi- ty inside the cathode (excluding the regions of about 3…4 cm thickness near the anode and the door) was not worse than ±20%. The discharge power supply was provided by DC source with controlled voltage and current values in ranges of 400…800 V and 100…600 mA, respectively. The cathode/chamber was grounded, and positive poten- tial was applied to the anode. Power Wd introduced in the discharge could be varied in range of 50…350 W ISSN 1562-6016. ВАНТ. 2015. №4(98) 178 which corresponded to specific power in the discharge Ws ≈ 1…7 mW/cm3. Cathode was evacuated down to pressure of about ~ 10-5 Torr, and after that working gas was supplied to the chamber until reaching of predetermined pressure value. Working gas pressure P of oxygen in the cathode was varied in range of 10-2…2⋅10-1 Torr. The electric field in the plasma was measured using double Langmuir probes, which could be moved along and across the cathode. The probes were made of two parallel 0.75 mm diameter wires having 10 mm length located at 10 mm distance from each other. To avoid the effect of contamination of the probes surface on the electric field value, the probes after each measurement were cleaned by means of ion current from the plasma (for that purpose, the probes were grounded for 5…10 s). 2. EXPERIMENTAL RESULTS AND DISCUSSION For correct determining the cathode layer thickness, measurements of radial distributions of electric field strength ER in the plasma were performed at the dis- charge power values Wd of 100 and 250 W, and oxygen pressure values P = 0.015, 0.3, 0.6 and 0.9 Torr. Fig. 1 presents the results of ER measurements, as well as cal- culated on a basis of these values radial potential fall UR in the plasma at Wd = 100 W and four values of O2 pressure. The values of potential UR were normalized so that they should coincide at the system axis. One can see from Fig.1,a that at all P values the dependence of ER on R possesses non-monotonous behavior – at first, it grows until a maximum with radius increase, after that it decreases, and after reaching a minimum it grows up again (the last ER growth corresponds to the region of cathode fall of the potential). Oxygen pressure increase results not only in decrease of electric field value ER in the plasma, but as well in a shift of ER minimum posi- tion towards the cathode surface. At that, with the pres- sure variation from 0.03 to 0.06 Torr, position of the minimum changes in a jump-like manner from ~ 12 to ~ 16 cm. Besides, at oxygen pressure values of 0.06 and 0.09 Torr the field ER in a region of the minimum exhib- its double change of its sign – at first, it becomes nega- tive, and in subsequent it changes to positive again. It is an evidence of formation of potential barrier in this re- gion, which prevents coming of the ions, originated in the negative glow plasma, to the cathode. The discharge power increase up to 250 W could lead just to increase of ER and U absolute values, with- out principal change of the overall behavior. A point of crossing the tangents to U vs R profile was taken as the cathode layer boundary. It was as- sumed that electric field in the cathode layer possesed linear dependence on R:    > <−− = dR dRdRoE RER ,0 ),/1( )( that is E ≈ Ud/d, where Ud is the discharge voltage, d is the cathode layer thickness (influence of potential fall at the discharge plasma and anode potential fall could be neglected in our case due to their small values). 0 4 8 12 16 20 0,0 0,1 0,2 0,3 0,4 10 20 a Ca th od eE R, V/ cm R, cm 0.015 Torr 0.03 Torr 0.06 Torr 0.09 Torr 0 4 8 12 16 20 -1,6 -1,2 -0,8 -0,4 0,0 Ca th od e b U R, V R, cm 0.09 Torr 0.06 Torr 0.03 Torr 0.015 Torr Fig. 1. Radial dependencies of radial component ER of electric field in the plasma (a) and potential U (b) at different oxygen pressure values. Wd = 100 W Dependence of the discharge voltage Ud on reduced discharge current density Jd/P2 (reduced CVC of the discharge) is presented in Fig. 2. 50 100 150 200 250 300 350 400 500 600 700 0 100 200 300 0,0 2,0x104 4,0x104 6,0x104 E R /P , V /( cm T o rr ) Jd/P 2, mA/(cm Torr)2 U d, V Jd/P 2, mA/(cm Torr)2 Fig. 2. Reduced CVC of the discharge at oxygen pressure variation in a range of 0.015…0.09 Torr, and Wd values of 100 and 250 W. An insert shows reduced electric field ER/P dependence on Jd/P2 obtained under the same conditions One can see from the figure that at Jd/P2 ~ 30…40 mA/(cm·Torr)2 this dependence exhibits a bend – rapid Ud growth is substituted by its slower in- crease. (It should be noted that Jd/P2 grows up with the pressure decrease, so that the left part of the curve (before the bend) corresponds to oxygen pressure values ~ 0.09…0.06 Torr). Thus, the pressure decrease below 0.06 Torr results in a change of the discharge glow mode. Dependence of reduced cathode layer thickness Pd on Jd/P2 (Fig. 3) possesses the same peculiarity – abrupt decrease of Pd at Jd/P2 ~ 30…40 mA/(cm·Torr)2. ISSN 1562-6016. ВАНТ. 2015. №4(98) 179 0 50 100 150 200 250 300 350 0,00 0,03 0,06 0,09 0,12 0,15 0,18 Pd ~ (Jd/P 2)-0.32 Pd , T or r c m Jd/P 2, mA/(cm Torr)2 Fig. 3. Dependence of reduced cathode layer thickness Pd on Jd/P2 in oxygen plasma at pressure variation from 0.015 to 0.09 Torr, and Wd value of 100 and 250 W For understanding what is going on in the discharge at oxygen pressure decrease below ~ 0.06 Torr, let us consider, how a run path of fast electrons Λf, which de- fines a length of the negative glow plasma [15] filling the cathode cavity, changes with the pressure variation. Authors of [16] for an estimation of Λf value have pro- posed empiric formula ,/)( pBUU ddf ≈Λ (1) where B is a constant in empiric Townsend formula for ionization coefficient )/exp(/ EBpAp −=α . (2) The authors motivate a correctness of such estimation by fact that in electron energy range of interest for us (~ 10…1000 eV) the dependencies of a majority of exci- tation and ionization cross sections possess very shallow maxima. Λf value obtained from (1) is in a good enough agreement with experimentally measured negative glow dimensions for nitrogen (Fig. 2 in [16]). However, table data for B in the case of large electric field values (>103 V/(cm·Torr)) are absent in the literature, while as one can see from Fig. 2, in our case reduced electric field ER/P in the cathode layer exceeds V/(cm·Torr). Due to that, constant B value was estimated by us on a basis of experimentally measured dependence of ionization co- efficient α/P for oxygen on reduced field E/P [17]. In variation range E/P ~ 103…104 V/(cm·Torr) В value was about 260…280 V/(cm·Torr). Estimations of elec- tron run path Λf in our oxygen plasma are presented in Fig. 4. Unfortunately, reliable data on differential cross section of elastic scattering of electrons with energy up to ~ 103 eV are practically absent, and as a result, in many papers it is assumed that scattering of electrons with energy up to ~ 50 eV occurs only in forward direc- tion. Due to that, in our estimations we also followed from this assumption. One can see from the figure that at oxygen pressure of 0.09 Torr the run path Λf is about 15…20 cm, which is close to the cathode radius R. Pres- sure decrease down to 0.03 Torr leads to Λf increase al- ready to ~ 50…60 cm, which corresponds to about 1.5 R. Let us consider a relation between the behavior of radial distribution of the plasma density Ne at different oxygen pressure values and estimated by us run path Λf values. For that that purpose we’ll use experimental data obtained in [18] with the same cathode dimensions and discharge parameters − power Wd = 250 W, and oxygen pressure values P = 0.09 and 0.03 Torr. 400 500 600 700 800 101 102 0,015 Torr 0.06 Torr 0.03 Torr 0.09 Torr Λ f , c m Ud, V Fig. 4. Dependence of the run path of fast electrons Λf on voltage Ud for different oxygen pressure values Fig. 5 exhibits experimental dependencies of radial distributions of the plasma density Ne obtained in [18] and schematic trajectories of fast electron motion inside the cathode cavity (length of the arrows corresponds to estimated run path Λf values). -20 -16 -12 -8 -4 0 4 8 12 16 20 1E9 1E10 Λf Λf a) N e, cm -3 R, cm -20 -16 -12 -8 -4 0 4 8 12 16 20 1E9 1E10 Λf Λf b) N e, cm -3 R, cm Fig. 5. Radial distributions of oxygen plasma density Ne (-•-) at P = 0.09 Torr (a) and 0.03 Torr (b); Wd = 250 W [18]. Arrows indicate trajectories of fast electron motion inside the cathode cavity One can see from Fig. 5 that at 0.09 Torr pressure the plasma density distribution has double-humped shape with a minimum at the cathode axis. It is due to fact that fast electrons accelerated in the cathode layer spend their whole energy without reaching the chamber axis. Since in that case an “overlapping” of negative glow plasmas does not occur, our discharge should be considered as a version of the discharge with flat cath- ode. Completely different behavior is observed at gas pressure decrease down to 0.03 Torr. The run path Λf is at that long enough, which enables fast electrons to cross the cathode cavity along its diameter, reflect from the cathode layer and subsequently return to the system axis. That is, an “overlapping” of negative glow plasma ISSN 1562-6016. ВАНТ. 2015. №4(98) 180 occurs, and fast electrons perform ionization not just in “their own plasma” (that is, in plasma where they start- ed their path), but as well in the whole volume of the cathode cavity. It results in both abrupt increase of the plasma density, and establishing its essentially more uniform spatial distribution. In turn, it should lead to change of the discharge characteristics, which can be seen in Figs. 2, 3. This change occurs at P ~ 0.06 Torr (see above), which corresponds to the run path Λf ~ 25…30 cm, that is, shorter than the cathode diame- ter. Thus, one can see that in our case the hollow cath- ode effect is exhibited at fast electron run path Λf being not shorter than ~ 3R of the hollow cathode. In the present work plasma characteristics of the discharge in low pressure oxygen with cylindrical hol- low cathode having 38 cm diameter are determined. It is shown that oxygen pressure increase from 0.015 to 0.09 Torr results in non-monotonous variation of radial profile of radial electric field component in the plasma and creation at pressure higher than Р ≈ 0.06 Torr the potential barrier at a boundary between the negative glow plasma and the cathode layer, which limits ion escaping to the cathode. As well, limits of the discharge glow characteristics are determined, which result in an appearance of the hollow cathode effect. ACKNOWLEDGEMENT This work was partially supported by grant # 10-14 of Presidium of National Academy of Sciences of Ukraine. REFERENCES 1. F. Paschen. Bohrs Heliumlinien // Ann. Phys. 1916, v. 50 (IV), p. 901. 2. S. Caroli, O. Senofonte. Hollow Cathode Discharges // Glow Discharge Spectroscopies / Ed. R. Kenneth Marcus. Plenum Press, New York, 1993, p. 215-262. 3. H Conrads, M. Schmidt. Plasma generation and plasma sources // Plasma Sources Sci. Technol. 2000, v. 9, p. 441-454. 4. M.A.M. Silva, A.E. Martinelli, C. Alves Jr., R.M. Nascimento, M.P. Tavora, C.D. Vilar. Surface modification of Ti implants by plasma oxidation in hollow cathode discharge // Surface & Coatings Technology. 2006, v. 200, p. 2618-2626. 5. Z. Hubicka, G. Pribila, R.J. Soukupa, N.J. Ianno. Investigation of the rf and dc hollow cathode plas- ma-jet sputtering systems for the deposition of sili- con thin films // Surface and Coatings Technology. 2002, v.160, p. 114-123. 6. B.I. Moskalev. Razryad s polym katodom. M.: “Ener- giya”, 1969 (in Russian). 7. I. Apostol, Yu.M. Kagan, R.I. Lyagushhenko, S.N. Xvorostovskij, M.A. Xodorkovskij. Raschet koncentracii i temperatury medlennyx elektronov v polom katode // ZhTF. 1976, v. 46, №. 9, p. 1997-1999 (in Russian). 8. A.S. Metel. Vliyanie ionizacii v katodnom sloe na xarakteristiki tleyushhego razryada s os- cilliruyushhimi elektronami // ZhTF. 1985, v. 55, № 10, p. 1928-1934 (in Russian). 9. V.I. Kolobov, L.D. Tsendin. Analytic model of the hollow cathode // Plasma Sources Sci. Technol. 1995, v. 4, p. 551-460. 10. R.R. Arslanbekov, A.A. Kudryavtsev, R.C. Tobin. On the hollow-cathode effect: conventional and modified geometry // Plasma Sources Sci. Technol. 1998, v. 7, p. 310-322. 11. K. Kutasi, Z. Donk´o. Hybrid model of a plane- parallel hollow-cathode discharge // J. Phys. D: Appl. Phys. 2000, v. 33, p. 1081-1089. 12. G.J.M. Hagelaar, D.B. Mihailova, J. van Dijk. Analyti- cal model of a longitudinal hollow cathode discharge // J. Phys. D: Appl. Phys. 2010, v. 43, p. 465204. 13. H. Amemiya, K. Ogawa. Characteristics of a hol- low-cathode discharge containing negative ions // J. Phys. D: Appl. Phys. 1997, v. 30, p. 879-888. 14. V.V. Tsiolko, V.Yu. Bazhenov, A.I. Shchedrin, A.G. Kalyuzhnaya. Measurements and Calculations of the Electron Distribution Function in the Electro- negative Plasma of a Hollow_Cathode Discharge in N2: SF6 Mixtures // Plasma Physics Reports. 2009, v. 35, № 10, p. 883-889. 15. V.I. Kolobov, L.D. Tsendin. Analitical model of the cathode region of a short glow discharge in light gases // Phys. Rev. A. 1992, v. 46, p. 7837-7852. 16. A.A. Kudryavtsev, A.V. Morin, L.D. Tsendin. Role of nonlocal ionization in formation of the short glow dis- charge // Tech. Phys. 2008, v. 53, № 8, p. 1029-1040. 17. M. Radmilovic-Radjenovic, B. Radjenovic, M. Klas, S. Matelcik. A semi-empirical expression for the first Townsend coefficient in strong electric field // EPL, 2014, v. 108, p. 65001. 18. V.V. Tsiolko, S.V. Matsevich, V.Yu. Bazhenov, V.M. Piun, A.V. Ryabtsev. Kinetic processes in negative glow plasma of low pressure discharge in oxygen // Problems of Atomic Science and Technol- ogy. Series “Plasma Electronics and New Methods of Acceleration”. 2013, № 4, iss. 8, p. 166-170. Article received 01.06.2015 РАЗРЯД С ПОЛЫМ КАТОДОМ В КИСЛОРОДЕ НИЗКОГО ДАВЛЕНИЯ: ПЕРЕХОДНОЙ РЕЖИМ В.Ю. Баженов, С.В. Мацевич, В.М. Пиун, В.В. Циолко Установлены характеристики горения разряда с цилиндрическим полым катодом при давлениях кислорода 0,015…0,09 Торр. Найдены зависимости радиального электрического поля в плазме от параметров разряда, в частности, установлен факт образования при давлениях больше ~ 0,06 Торр потенциального барьера на границе между плазмой отрицательного свечения и катодным слоем, ограничивающего уход ионов на катод. Также установлены граничные ха- рактеристики горения разряда, при которых начинает проявляться эффект полого катода. РОЗРЯД З ПОРОЖНИСТИМ КАТОДОМ У КИСНІ НИЗЬКОГО ТИСКУ: ПЕРЕХІДНИЙ РЕЖИМ В. Ю. Баженов, С.В. Мацевич, В.М. Піун, В.В. Ціолко Встановлено характеристики горіння розряду з циліндричним порожнистим катодом при тисках кисню 0,015…0,09 Торр. Знайдено залежності радіального електричного поля в плазмі від параметрів розряду, зокрема, встано- влено факт утворення при тисках більше ~ 0,06 Торр потенціального бар’єру на границі між плазмою негативного сві- тіння та катодним шаром, який обмежує вихід іонів на катод. Також встановлено граничні характеристики горіння роз- ряду, при яких починає проявлятися ефект порожнистого катодa. ACKNOWLEDGEMENT References
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1562-6016
language English
last_indexed 2025-12-01T13:54:32Z
publishDate 2015
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spelling Bazhenov, V.Yu.
Matsevich, S.V.
Piun, V.M.
Tsiolko, V.V.
2017-01-17T17:54:48Z
2017-01-17T17:54:48Z
2015
Hollow cathode discharge in low pressure oxygen: transient mode / V.Yu. Bazhenov, S.V. Matsevich, V.M. Piun, V.V. Tsiolko // Вопросы атомной науки и техники. — 2015. — № 4. — С. 177-180. — Бібліогр.: 18 назв. — англ.
1562-6016
PACS: 52.80.-s, 52.25.Ya
https://nasplib.isofts.kiev.ua/handle/123456789/112135
Glow characteristics of the discharge with cylindrical hollow cathode at oxygen pressure in a range of 0.015…0.09 Torr are determined. Dependencies of radial electric field in the plasma on the discharge parameters are defined, and particular fact of creation at pressure higher than ~ 0.06 Torr the potential barrier at the boundary between negative glow plasma and cathode layer, which limits ion escaping to the cathode. As well, limits of the discharge glow characteristics are determined, which result in appearance of the hollow cathode effect.
Встановлено характеристики горіння розряду з циліндричним порожнистим катодом при тисках кисню 0,015…0,09 Торр. Знайдено залежності радіального електричного поля в плазмі від параметрів розряду, зокрема, встановлено факт утворення при тисках більше ~ 0,06 Торр потенціального бар’єру на границі між плазмою негативного світіння та катодним шаром, який обмежує вихід іонів на катод. Також встановлено граничні характеристики горіння розряду, при яких починає проявлятися ефект порожнистого катодa.
Установлены характеристики горения разряда с цилиндрическим полым катодом при давлениях кислорода 0,015…0,09 Торр. Найдены зависимости радиального электрического поля в плазме от параметров разряда, в частности, установлен факт образования при давлениях больше ~ 0,06 Торр потенциального барьера на границе между плазмой отрицательного свечения и катодным слоем, ограничивающего уход ионов на катод. Также установлены граничные ха-рактеристики горения разряда, при которых начинает проявляться эффект полого катода.
This work was partially supported by grant # 10-14 of Presidium of National Academy of Sciences of Ukraine.
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
Плазменно-пучковый разряд, газовый разряд и плазмохимия
Hollow cathode discharge in low pressure oxygen: transient mode
Розряд з порожнистим катодом у кисні низького тиску: перехідний режим
Разряд с полым катодом в кислороде низкого давления: переходной режим
Article
published earlier
spellingShingle Hollow cathode discharge in low pressure oxygen: transient mode
Bazhenov, V.Yu.
Matsevich, S.V.
Piun, V.M.
Tsiolko, V.V.
Плазменно-пучковый разряд, газовый разряд и плазмохимия
title Hollow cathode discharge in low pressure oxygen: transient mode
title_alt Розряд з порожнистим катодом у кисні низького тиску: перехідний режим
Разряд с полым катодом в кислороде низкого давления: переходной режим
title_full Hollow cathode discharge in low pressure oxygen: transient mode
title_fullStr Hollow cathode discharge in low pressure oxygen: transient mode
title_full_unstemmed Hollow cathode discharge in low pressure oxygen: transient mode
title_short Hollow cathode discharge in low pressure oxygen: transient mode
title_sort hollow cathode discharge in low pressure oxygen: transient mode
topic Плазменно-пучковый разряд, газовый разряд и плазмохимия
topic_facet Плазменно-пучковый разряд, газовый разряд и плазмохимия
url https://nasplib.isofts.kiev.ua/handle/123456789/112135
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