Comparing properties of dc discharges in tubes possessing a hollow cathode or anode in an undergraduate laboratory

Lisovskiy, Valeriy; Khilko, D. I.; Osmayev, R.O.; Yegorenkov, Vladimir

doi:10.1088/1361-6404/ab1a59

Cited by 5 publications

(10 citation statements)

References 39 publications

(46 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A portion of positive ions, entering the cathode sheath from the negative glow near the edges of the cathode plates, hits the cathode surface inside the cavity. The secondary electrons produced by the ion-electron emission are focused by the electric field of the cavity and they form the electron beam directed along the discharge axis to the anode (a more detailed picture of the electron beam production is described in papers [12,21,22]). But when the anode is located too close to the cathode, the probability for ions to get into the cavity is small, therefore the electron beam is not observed.…”

Section: Resultsmentioning

confidence: 99%

Structure and Properties of Glow Discharge in Argon With Hollow Cathode

Lisovskiy¹,

Osmayev²,

Khilko³

et al. 2019

Problems of Atomic Science and Technology

View full text Add to dashboard Cite

This paper deals with studying into the modes of burning and structure of the glow discharge with a hollow cathode and a flat anode in argon. We have demonstrated that the electron beam usually leaving the cathode cavity in a high voltage (glow mode) disappears when the anode approaches the edge of the hollow cathode. In this case the discharge is burning only on the outer surface of the cathode plates forming the cavity. The anode motion does not affect essentially the properties of the discharge burning in the hollow mode. We have obtained the axial intensity profiles of the emission lines of argon atoms and ions in the hollow and glow modes for various gas pressure and discharge current values. We have also shown that the brightest lines correspond to the transitions from 3p54p to 3p54s levels. The lines corresponding to the transitions from higher levels as well as the emission lines of argon ions possess a rather low intensity.

show abstract

Section: Resultsmentioning

confidence: 99%

Structure and Properties of Glow Discharge in Argon With Hollow Cathode

Lisovskiy¹,

Osmayev²,

Khilko³

et al. 2019

Problems of Atomic Science and Technology

View full text Add to dashboard Cite

show abstract

“…One of the features of a hollow cathode discharge is the anomalously low value of the width of the cathode dark space and its weak dependence on the gas pressure [4], [9]. The width of the region of the cathode dark space in the plasma hollow cathode was measured using the curves of the radial distribution of the glow intensity.…”

Section: Eejp 2 (2021)mentioning

confidence: 99%

Influence of Electron Injection on the Characteristics of a Hollow Cathode Glow Discharge

2021

EEJP

View full text Add to dashboard Cite

The article presents the results of experimental studies of a glow discharge with a hollow cathode in helium and argon gases using an auxiliary discharge as an electron emitter. The authors proposed to make the electrode common for both discharges in the form of a cylindrical metal mesh. The advantage of this design is explained as follows. The connection between the discharges is carried out through holes in the grid with a geometric transparency of 0.2, which makes it possible not only to smoothly control the glow discharge current, but also to enhance the discharge current. Plasma is known to be one of the most efficient electron emitters; however, its use as a cathode in devices with a glow discharge at low gas pressures is complicated by the fact that a grid with small holes is required to separate the electron flow from the plasma, and it is impractical to use such a system in view of low mechanical strength of the grid Since the hollow cathode works effectively at low gas pressures, the release of an electron flux from the plasma of some auxiliary discharge is possible with much larger holes in the grid separating the plasma and the hollow cathode cavity. In this case, the grid can be made such that it can withstand sufficiently high thermal loads and can operate in typical discharge modes with a hollow cathode. The injection of electrons into the cathode cavity of the glow discharge changes the radial distribution of the glow intensity, the width of the cathode dark space, and other parameters of the plasma in the cathode cavity. The influence of electrons penetrating from the auxiliary discharge into the cathode cavity of the main discharge becomes significant when the current of these electrons is comparable to or exceeds the current of electrons leaving the grid cathode surface as a result of γ-processes. In parallel with the measurement of the optical and electrical characteristics of the hollow cathode glow discharge plasma, measurements of the electron concentration were carried out by the microwave sounding method. The entire current of the auxiliary discharge penetrates into the cavity of the main discharge; however, after acceleration in the cathode dark space, the electrons penetrating from the auxiliary discharge ionize gas atoms and noticeably increase the current of the main discharge. Additional ions formed due to the ionization of the gas by the injected electrons knock out new electrons from the cathode surface, which makes it possible to increase the discharge current.

show abstract

“…Therefore a large number of papers are devoted to experimental and theoretical studies of the discharge with a hollow cathode (see e.g. [10][11][12][13][14][15][16]).…”

Section: Introductionmentioning

confidence: 99%

“…The shape of a hollow cathode is chosen such that it may be optimally applied in a given plasma technology. In the common glow discharge with flat cathode electrons that escape the sheath can lose their energy along the full length of the negative glow which can measure in tenths of centimeters [14,17,18] in low pressures. In a hollow cathode that is filled with negative glow (in the so-called hollow mode) almost all the energy gathered by electrons is dissipated within the cavity itself, which allows the high density plasma to stay there [12,15,16].…”

Section: Introductionmentioning

confidence: 99%

Glow Discharge With a Hollow Cathode in Carbon Dioxide

Lisovskiy¹,

Dudin²,

Platonov³

et al. 2022

Problems of Atomic Science and Technology

View full text Add to dashboard Cite

This paper is devoted to an experimental study of the dc discharge with a hollow cathode within the carbon dioxide pressure range of 0.06...2 Torr. The registered CVCs in the pressure range below 0.5 Torr possess a hysteretic pattern with transitions between glow and hollow modes. We have demonstrated that the value of the product of gas pressure and distance between cathode plates p·dh = 0.32 Torr·cm is optimum for the application of the discharge with hollow cathode for plasma conversion of the carbon dioxide when the maximum discharge current is observed. Then the cathode cavity is filled with a high density discharge. Treating the optical emission spectrum has revealed that in the negative glow there have to be present the electron flows with the energy above 18 eV, what must provide the high rate of the CO2 molecules conversion via direct electron impact. Slow electrons produced inside the negative glow itself have to supply an additional contribution to the conversion process and to make an efficient excitation of oscillatory levels of CO2 molecules.

show abstract

Comparing properties of dc discharges in tubes possessing a hollow cathode or anode in an undergraduate laboratory

Cited by 5 publications

References 39 publications

Structure and Properties of Glow Discharge in Argon With Hollow Cathode

Structure and Properties of Glow Discharge in Argon With Hollow Cathode

Influence of Electron Injection on the Characteristics of a Hollow Cathode Glow Discharge

Glow Discharge With a Hollow Cathode in Carbon Dioxide

Contact Info

Product

Resources

About