Investigation of arcing on fiber-formed nanostructured tungsten by pulsed plasma during steady state plasma irradiation

Yajima, Miyuki; Ohno, Noriyasu; Kajita, Shin; Temmerman, G. De; Bystrov, K.; Bardin, S.; Morgan, T.W.; Masuzaki, S.

doi:10.1016/j.fusengdes.2016.07.026

Cited by 22 publications

(11 citation statements)

References 25 publications

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“…Arc ignition is harmful to fusion devices because it can be a cause of erosion of PFC and an impurity source to a core plasma . As the first laboratory experiment was conducted in 2009, much subsequent research has characterized several properties of the arcing, including ignition and duration conditions . Arc ignition was particularly evident on W‐fuzz surfaces when the target potential against the plasma potential was below −60 V, whereas arcs did not ignite when the target potential was higher than −60 V .…”

Section: Introductionmentioning

confidence: 99%

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Ignition and erosion of materials by arcing in fusion‐relevant conditions

Hwangbo

Kajita

Barengolts

et al. 2018

Contributions to Plasma Physics

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This study investigated the characteristics of arcing initiated on nanostructured fuzzy tungsten (W) surfaces in helium (He) plasmas. Under the same He plasma conditions, the relationship between arc voltage and current was characterized as linear due to plasma resistance across the He plasma from the target surface to the plasma source. Properties of the erosion caused by arcing were investigated by focusing on two parameters: arc current and fuzzy layer thickness. The erosion per charge was significantly dependent on the thickness of the fuzzy layer but did not depend on the arc current. Sample surface analysis revealed that drastic changes in arc spot grouping features were accompanied by the fuzzy layer thickness variation. The ecton model indicated that the erosion as ions does not play a main role, but mechanical destruction by momentum transfer from the explosive electron emission centre to neighbouring nanowires seems to enhance the erosion greatly.

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Section: Introductionmentioning

confidence: 99%

“…Therefore, an unknown factor may exist at the point of discrepancy between the minimum target potential and the potential fall required in Refs. .…”

Section: Introductionmentioning

confidence: 99%

Ignition and erosion of materials by arcing in fusion‐relevant conditions

Hwangbo

Kajita

Barengolts

et al. 2018

Contributions to Plasma Physics

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“…Extensive studies have been undertaken to investigate the electrical properties and arc characteristics of the WCu contact materials. Results showed that refining of grains and micro-alloying provide the WCu contact materials with higher strength and improved dispersion of arc characteristics, thus effectively inhibiting the premature ablation failure of the contacts 3 – 6 . However, even though the above methods have been applied, there still remains a contradictory issue to simultaneously increase both the strength and electrical conductivity of the contact materials.…”

Section: Introductionmentioning

confidence: 99%

Synergistic enhancing effect for mechanical and electrical properties of tungsten copper composites using spark plasma infiltrating sintering of copper-coated graphene

Chen

Dong

Wang

et al. 2017

Sci Rep

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Successful applications of WCu alloys in high voltage electrical switches require their high strength and excellent conductivity. Unfortunately, the strategies for increasing their strength such as doping with fine particles and alloying often significantly decrease their conductivity. In this paper, we developed a new pathway for fabricating WCu alloys using spark plasma infiltrating sintering of copper-coated graphene (Cu@Gr) composite powders. Cu@Gr was found to partially prevent the formation of WC after sintering, and graphene was uniformly distributed on the surfaces of network Cu phases. Electrical conductivity of 38.512 M·S/m, thermal conductivity of 264 W·m−1·K−1 and microhardness of 278 HV were achieved for the sintered WCu composites doped with only 0.8 wt.% Cu@Gr powders, which showed 95.3%, 24.3%, 28% enhancement compared with those from the conventional sintering using the undoped WCu powders.

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“…Extensive studies have been undertaken to investigate the electrical properties and arc characteristics of the WCu contact materials. Results showed that refining of grains and micro-alloying provide the WCu contact materials with higher strength and improved dispersion of arc characteristics, thus effectively inhibiting the premature ablation failure of the contacts 3,4,5,6 . However, even though the above methods have been applied, there still remains a contradictory issue to simultaneously increase both the strength and electrical conductivity of the contact materials.…”

mentioning

confidence: 99%