scholarly journals Influence of accelerating gap configuration on parameters of a forevacuum plasma-cathode source of pulsed electron beam

2021 ◽  
Vol 2064 (1) ◽  
pp. 012123
Author(s):  
A V Kazakov ◽  
A V Medovnik ◽  
E M Oks ◽  
N A Panchenko
Keyword(s):  
Electron Beam ◽  
Electron Emission ◽  
Gas Pressure ◽  
Emission Current ◽  
Electron Beam Current ◽  
Large Radius ◽  
Optimal Length ◽  
Plasma Cathode ◽  
Maximum Emission ◽  
Emission Efficiency

Abstract The research of influence of accelerating gap configuration on parameters of a forevacuum plasma-cathode source of a pulsed low-energy (up to 10 keV) large-radius electron beam is presented. An increase in cell sizes of a mesh emission electrode increases electron emission efficiency, but leads to a decrease in electric strength of an accelerating gap. Larger cell sizes of a mesh extractor provide higher electron beam current. An increase in the length of the accelerating gap first leads to an increase in the electron emission efficiency, but when optimal value is reached, a further increase in the length leads to a decrease in the emission efficiency. This optimal length of the accelerating gap is about 25 mm. However, the electron emission efficiency changes relatively small (within 15%). The dependencies of maximum emission current and maximum operating gas pressure on the length of acceleration gap is similar to the dependence for the emission efficiency, but the gap length much stronger influences on these maximum values. Moreover, the optimal length, at which maximum emission current or maximum pressure is provided, is depended on gas pressure (for current) or emission current (for pressure), accelerating voltage and pulse duration.

scholarly journals Influence of electron emission on operation of a constricted arc discharge in a pulsed forevacuum plasma-cathode electron source

2021 ◽  
Vol 2064 (1) ◽  
pp. 012124
Author(s):  
A V Kazakov ◽  
E M Oks ◽  
N A Panchenko
Keyword(s):  
Electron Beam ◽  
Electron Emission ◽  
Arc Discharge ◽  
Electron Source ◽  
Operating Voltage ◽  
Large Radius ◽  
Plasma Cathode ◽  
Discharge System ◽  
Arc Voltage ◽  
Minimum Value

Abstract The research of influence of electron emission and processes associated with the formation of a pulsed large-radius electron beam on operation of a constricted arc discharge, which forms emission plasma in a forevacuum plasma-cathode electron source, is presented. Processes, occurring in case of generation of the electron beam at forevacuum pressure range 3–20 Pa, provide lower operating voltage of the constricted arc discharge. The constricted arc voltage decreases with increasing pressure and increasing accelerating voltage. However, at pressure more than 15 Pa, the arc voltage decreases until a certain minimum value is reached, and then arc voltage is almost independent on pressure and accelerating voltage. This minimum value of the constricted arc voltage is on average 1.5–2 times higher as compared with voltage of the cathodic arc at the same discharge current. The observed decrease of operating voltage of the constricted arc is most likely caused by accelerated back-streaming ions, which move toward the emission electrode from beam-produced plasma. These accelerated ions partially penetrate into the hollow anode of discharge system through the mesh emission electrode and facilitate formation of the arc plasma, and thus provides lower voltage of the constricted arc.

Generation of Millisecond Low-Energy Large-Radius Electron Beam by a Forevacuum Plasma-Cathode Source

2019 ◽  
Vol 47 (8) ◽  
pp. 3579-3585 ◽  
Author(s):  
Andrey V. Kazakov ◽  
Alexander V. Medovnik ◽  
Efim M. Oks
Keyword(s):  
Electron Beam ◽  
Low Energy ◽  
Large Radius ◽  
Plasma Cathode

Effect of gas pressure on amplitude and duration of electron beam current in a gas-filled diode

2008 ◽  
Vol 53 (12) ◽  
pp. 1560-1564 ◽  
Author(s):  
E. H. Baksht ◽  
M. I. Lomaev ◽  
D. V. Rybka ◽  
D. A. Sorokin ◽  
V. F. Tarasenko
Keyword(s):  
Electron Beam ◽  
Beam Current ◽  
Gas Pressure ◽  
Electron Beam Current

scholarly journals Field-emission electron gun for a MEMS electron microscope

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Michał Krysztof
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Field Emission ◽  
Control Function ◽  
Electron Gun ◽  
Emission Current ◽  
Electron Beam Current ◽  
Anode Current ◽  
Current Limit ◽  
Emission Electron

AbstractThis article presents a field-emission electron gun intended for use in a MEMS (microelectromechanical system) electron microscope. Its fabrication process follows the technology of a miniature device under development built from silicon electrodes and glass spacers. The electron gun contains a silicon cathode with a single very sharp protrusion and a bundle of disordered CNTs deposited on its end (called a sharp silicon/CNT cathode). It was tested in diode and triode configurations. For the diode configuration, a low threshold voltage <1000 V and a high emission current that reached 90 µA were obtained. After 30 min of operation at 900 V, the emission current decreased to 1.6 µA and was stable for at least 40 min, with RMS fluctuation in the anode current lower than 10%. The electron beam spot of the source was observed on the phosphor screen. In the diode configuration, the spot size was the same as the emission area (~10 µm), which is a satisfactory result. In the triode configuration, an extraction electrode (gate) control function was reported. The gate limited the emission current and elongated the lifetime of the gun when the current limit was set. Moreover, the electron beam current fluctuations at the anode could be reduced to ~1% by using a feedback loop circuit that controls the gate voltage, regulating the anode current. The developed sharp silicon/CNT cathodes were used to test the MEMS electron source demonstrator, a key component of the MEMS electron microscope, operating under atmospheric pressure conditions. Cathodoluminescence of the phosphor layer (ZnS:Ag) deposited on the thin silicon nitride membrane (anode) was observed.

scholarly journals Formation of beam-produced plasma by a forevacuum plasma-cathode source of a pulsed large-radius electron beam

2021 ◽  
Vol 1989 (1) ◽  
pp. 012037
Author(s):  
A V Kazakov ◽  
A V Medovnik ◽  
E M Oks ◽  
N A Panchenko
Keyword(s):  
Electron Beam ◽  
Large Radius ◽  
Plasma Cathode

Influence of gas pressure on electron beam emission current of pulsed cathodic-arc-based forevacuum plasma electron source

2017 ◽  
Vol 24 (9) ◽  
pp. 093109 ◽  
Author(s):  
Victor A. Burdovitsin ◽  
Andrey V. Kazakov ◽  
Alexander V. Medovnik ◽  
Efim M. Oks
Keyword(s):  
Electron Beam ◽  
Plasma Electron ◽  
Electron Source ◽  
Gas Pressure ◽  
Emission Current ◽  
Plasma Electron Source ◽  
Cathodic Arc

scholarly journals Thermionic Electron Beam Current and Accelerating Voltage Controller for Gas Ion Sources

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2878
Author(s):  
Jarosław Sikora ◽  
Bartosz Kania ◽  
Janusz Mroczka
Keyword(s):  
Electron Beam ◽  
Beam Current ◽  
Ion Source ◽  
Ion Sources ◽  
Emission Current ◽  
Measuring Instruments ◽  
Electron Beam Current ◽  
Mass Spectrometers ◽  
Source Power ◽  
Voltage Controller

Thermionic emission sources are key components of electron impact gas ion sources used in measuring instruments, such as mass spectrometers, ionization gauges, and apparatus for ionization cross-section measurements. The repeatability of the measurements taken with such instruments depends on the stability of the ion current, which is a function, among other things, of the electron beam current and electron accelerating voltage. In this paper, a laboratory thermionic electron beam current and accelerating voltage controller is presented, based on digital algorithm implementation. The average value of the percentage standard deviation of the emission current is 0.021%, and the maximum electron accelerating voltage change versus the emission current is smaller than 0.011% in the full operating range of the emission current. Its application as a trap current or emission current-regulated ion source power supply could be useful in many measuring instruments, such as in microelectromechanical system (MEMS) mass spectrometers as universal gas sensors, where a stable emission current and electron energy are needed.

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