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.

scholarly journals Generation, transport, and efficient extraction of a large cross-section electron beam into an air in an accelerator with a mesh plasma cathode

2018 ◽  
Vol 36 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Maxim S. Vorobyov ◽  
Tamara V. Koval ◽  
Nikolay N. Koval ◽  
Nguyen Bao Hung
Keyword(s):  
Electron Beam ◽  
Cross Section ◽  
Beam Energy ◽  
Arc Discharge ◽  
Theoretical Research ◽  
Metal Foil ◽  
Large Cross Section ◽  
Plasma Parameters ◽  
Plasma Cathode ◽  
Discharge System

AbstractThe paper presents experimental and theoretical research data on the generation, transport, and extraction of a large cross-section (750 × 150 mm2) electron beam into the air through a thin metal foil in an accelerator with a mesh plasma cathode on the bases of a low-pressure arc and with a multi-aperture two-electrode electron-optical system. When the burning conditions of the arc discharge, responsible for the generation of the emission plasma, is changed, the characteristics of this plasma were investigated, including under the conditions of the selection of electrons from it. Our experiments show that at an accelerating voltage of 200 kV, current in the accelerating gap of up to 30 A, and full width at half maximum of up to 100 µm, the average extracted power is ≈4 kW and the extracted beam current is ≈85% from the common current into the accelerating gap. Our numerical estimates give a good correlation between the arc and emission plasma parameters depending on the electrode configuration in the discharge system and on the mechanism of electron beam generation. Analysis of the emission plasma parameters under different arc conditions and of the mechanisms responsible for the beam energy loss suggests that most of the energy in the accelerator is lost at the support grid and at the output foil due to defocusing of the beam and partial electron reflection from the foil. Other mechanisms that decrease the extracted beam energy are discussed.

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.

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

Double-coil magnetic focusing of the electron beam generated by a plasma-cathode electron source

2019 ◽  
Vol 90 (2) ◽  
pp. 023302 ◽  
Author(s):  
I. Yu. Bakeev ◽  
A. S. Klimov ◽  
E. M. Oks ◽  
A. A. Zenin
Keyword(s):  
Electron Beam ◽  
Electron Source ◽  
Plasma Cathode ◽  
Magnetic Focusing

scholarly journals Forevacuum plasma source of continuous electron beam

2019 ◽  
Vol 37 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Aleksandr Klimov ◽  
Ilya Bakeev ◽  
Efim Oks ◽  
Aleksey Zenin
Keyword(s):  
Electron Beam ◽  
Power Density ◽  
Hollow Cathode ◽  
Plasma Source ◽  
Electron Source ◽  
Hollow Cathode Discharge ◽  
Maximum Power ◽  
Maximum Power Density ◽  
Plasma Cathode ◽  
Pressure Plasma

AbstractWe describe here the design, main parameters, and characteristics of a forevacuum-pressure plasma-cathode electron source based on a hollow-cathode discharge. The source generates a continuous focused electron beam with energy up to 30 keV and current up to 300 mA at a pressure of 10–50 Pa. The focused electron beam reaches a maximum power density of 106 W/cm2. The source utility has been demonstrated by its application for processing and cutting of ceramic.

scholarly journals PLASMA CHARACTERISTICS IN SQUARE PULSE ARC DISCHARGE OF PLASMA CATHODE ELECTRON SOURCE DEVICE

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Agus Purwadi ◽  
Bambang Siswanto ◽  
Wirjoadi . ◽  
Lely Susita R.M. ◽  
Sudjatmoko .
Keyword(s):  
Discharge Plasma ◽  
Arc Discharge ◽  
Debye Length ◽  
Electron Plasma ◽  
Pulse Mode ◽  
Electron Source ◽  
Anode Chamber ◽  
Plasma Current ◽  
Plasma Parameters ◽  
Plasma Cathode

Plasma parameters in Plasma Cathode Electron Source Device (PCESD) are very important things because they will determine the eficiency of its electron extraction. Square pulse mode of PCESD’s arc discharge plasma current can be obtained by using Pulse Forming Network (PFN) circuits which is called Arc Discharge Power Supply (ADPS). The square pulse mode is necessity to simplify in electron irradiation dose calculation. ADPS is connected with Hollow Anode Chamber (HAC) which is placed inside of PCESD to produce arc discharge plasma. The value of arc discharge plasma current is the main key to determine plasma parameters that can be measured by using Rogowski coil. The value of the arc discharge plasma current is IADPS = 206.30 A with pulse width  = 80 μs. Whereas the plasma parameters values inside of the HAC are: the electron plasma density ne = (16.85  1019) m-3, electron plasma temperature Te = 2.609 eV, electron plasma frequency fe = 116.74 GHz, and Debye length λD = 9.958 µm respectively.

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