scholarly journals Surface modification of hypereutectic silumin subjected to a millisecond modulated electron beam treatment

2021 ◽  
Vol 2064 (1) ◽  
pp. 012045
Author(s):  
K T Ashurova ◽  
M S Vorobyov ◽  
E A Petrikova ◽  
Yu F Ivanov ◽  
P V Moskvin ◽  
...  

Abstract In this work, using a unique feature of the “SOLO” electron source with a grid plasma cathode based on a low-pressure arc discharge, which consists in the possibility of controlled operation of the beam power during a pulse of submillisecond duration, and, accordingly, the rate of energy input into the sample surface, we investigated the modes irradiation of samples of hypereutectic silumin. The irradiation modes had the same energy density during the first 200 μs of the pulse, equal to 20 J/cm2 and differed in different durations of further maintaining the surface temperature at 600°C for a time of up to 1 ms. The results of tribological tests and methods of diffraction microscopy of the investigated defect structure, the elemental and phase composition, the morphology of the strengthening phases of the modified layer of the hypereutectic silumin samples are presented.

Author(s):  
М.С. Воробьёв ◽  
П.В. Москвин ◽  
В.И. Шин ◽  
Н.Н. Коваль ◽  
К.Т. Ашурова ◽  
...  

The paper describes a method for a controlled change in the power of an electron beam during a pulse of submillisecond duration, using a source "SOLO" with a plasma cathode. The beam power is controlled by changing the amplitude of the beam current with a corresponding change in the concentration of the emission plasma. This control method allows generating submillisecond beams of variable power (up to 10 MW at a maximum rate of change of no more than 0.5 MW/µs), which can be used for processing various metallic materials in order to change the functional properties of their surface with the ability to control the rate of input of beam energy into the surface of these materials.


2021 ◽  
Vol 2064 (1) ◽  
pp. 012124
Author(s):  
A V Kazakov ◽  
E M Oks ◽  
N A Panchenko

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.


2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Agus Purwadi ◽  
Bambang Siswanto ◽  
Wirjoadi . ◽  
Lely Susita R.M. ◽  
Sudjatmoko .

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.


2018 ◽  
Vol 36 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Maxim S. Vorobyov ◽  
Tamara V. Koval ◽  
Nikolay N. Koval ◽  
Nguyen Bao Hung

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.


1998 ◽  
Vol 60 (4) ◽  
pp. 775-786 ◽  
Author(s):  
GEORGE HATHAWAY ◽  
PETER GRANEAU ◽  
NEAL GRANEAU

This paper reports progress in an experimental investigation, started in the Hathaway laboratory in 1994, dealing with the liberation of intermolecular bond energy from ordinary water by means of an arc discharge. Photographic evidence of fog generation and explosion during the arcing period is included. A new fog accelerator is described and a table of results of the kinetic energies of fog jets is provided. A renewable water energy cycle is outlined. The fog kinetic energy has been found to be greater than the difference between the capacitor input energy and the heat losses. Given energy conservation, the only external energy input that can account for the fog kinetic energy is solar heat from the atmosphere.


2017 ◽  
Vol 45 (8) ◽  
pp. 2075-2079 ◽  
Author(s):  
Alexander V. Medovnik ◽  
Viktor A. Burdovitsin ◽  
Andrey V. Kazakov ◽  
Efim M. Oks

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