Electron beam treatment of non-conducting materials by a fore-pump-pressure plasma-cathode electron beam source

Бурдовицин, В. А.; Климов, А. С.; Medovnik, A. V.; Окс, Е. М.

doi:10.1088/0963-0252/19/5/055003

Cited by 73 publications

(32 citation statements)

References 15 publications

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“…If instead, the joint material were the same as the parent material (PM), concerns of chemical stability and neutron irradiation tolerance could be minimized. Therefore, fusion joining technologies, such as laser or electron beam welding, could become attractive joining options . Previously, fusion welding of ultra‐high temperature ceramics has been demonstrated through the use of various arc welding techniques .…”

Section: Introductionmentioning

confidence: 99%

Solidification of welded SiC–ZrB₂–ZrC ceramics

et al. 2018

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A silicon carbide‐based ceramic, containing 50 vol% SiC, 35 vol% ZrB2, and 15 vol% ZrC was plasma arc welded to produce continuous fusion joints with varying penetration depth. The parent material was preheated to 1450°C and arc welding was successfully implemented for joining of the parent material. A current of 138 A, plasma flow rate of ~1 L/min or ~0.5 L/min, and welding speed of ~8 cm/min were utilized for repeated joining, with full penetration fusion zones along the entire length of the joints. Solidification was determined to occur through the crystallization of β‐SiC (3C), then the simultaneous solidification of SiC and ZrB2, and lastly through the simultaneous solidification of SiC, ZrB2, and ZrC through a ternary eutectic reaction. The ternary eutectic composition was determined to be 35.3 ± 2.2 vol% SiC, 39.3 ± 3.8 vol% ZrB2, and 25.4 ± 3.0 vol% ZrC. A dual fusion zone microstructure was always observed due to convective melt pool mixing. The SiC content at the edge of the fusion zone was 57 vol%, while SiC content at the center of the fusion zone was 42 vol% although the overall SiC content was still nominally 50 vol% throughout the entire fusion zone.

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Section: Introductionmentioning

confidence: 99%

Solidification of welded SiC–ZrB₂–ZrC ceramics

et al. 2018

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“…The electron beams (e-beams) of moderate energy (ε ≤ 25 keV) and the non-thermal plasma created by these beams are widely used in various fields of science and practice: gas lasers excitation [1], surface modification of various materials [2,3], creation of new materials including nano-powders [4], etc. Some information about the formation of such electron beams can be found in [5,6].…”

Section: Introductionmentioning

confidence: 99%

25 keV electron beam formation based on a three-electrode system of the obstructed glow discharge in H2 and D2

Akishev

Karalnik

Medvedev

et al. 2017

J. Phys.: Conf. Ser.

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25 keV electron beam formation based on a threeelectrode system of the obstructed glow discharge in H2 and D2 Abstract. The results of experimental study on the formation of high-current electron beams using three-electrode system are presented. This system enables to create a diffusive obstructed glow discharge in a pulsed regime with an amplitude of applied voltage up to 25 kV. The influence of such experimental parameters as the pressure of plasma forming gas and the amplitude of applied voltage on the obstructed glow discharge duration was investigated. Both the transverse and the longitudinal structure of formed electron beam was determined. IntroductionThe electron beams (e-beams) of moderate energy (ε ≤ 25 keV) and the non-thermal plasma created by these beams are widely used in various fields of science and practice: gas lasers excitation [1], surface modification of various materials [2,3], creation of new materials including nano-powders [4], etc. Some information about the formation of such electron beams can be found in [5,6]. The e-beams of moderate energy are perspective for the creation of small-sized neutron source based on the superstrong charging of dust particles [7]. In this source, the e-beam provides both the plasma around dust particles and their super-strong charging up to the potential energy equal to e-beam energy. Positive ions accelerate in the strong electric field of charged particle and increase their energy to high magnitude. The impact of high-energy ions with a particle leads to nuclear fusion reactions accompanied by neutron release. The numerical modeling of dust particles charging and nuclear fusion reactions [7] enabled us to formulate the requirements to the discharge and e-beam parameters providing the optimum experimental conditions for generation of neutrons. It was shown also that the most suitable plasma forming gas was deuterium. In this paper, the experimental results on the generation of pulsed high-current e-beam with the energy up to 25 keV are presented. The experiments were performed in H2 and D2 at pressure P = 0.5 -2 Torr. The e-beam was generated by the obstructed glow discharge using a triple electrode system of an original construction. This e-beam source will be used for generation of neutrons due to super-high charging of dust particles by the ebeam.

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“…The method is used to advantage for deposition of metal coatings [7]. Electron beam evaporation of dielectrics involves some problems and the major one is surface charging by beam electrons [8], eventually resulting in a retarding electric field. The process of evaporation, as a rule, is realized in vacuum at a pressure of 10 -2 -10 -4 Pa due to the use of thermionic-cathode electron guns [4] for which the pressure and the gas composition are critical.…”

Section: Introductionmentioning

confidence: 99%