Suche nach „[C.] [Niu]“ hat 2 Publikationen gefunden

NachhaltigElektrotechnik und MedientechnikIQMA

Zeitschriftenartikel

H. Fan, Y. Zhang, D. Liu, C. Niu, L. Liu, W. Ni, Y. Xia, Z. Bi, Günther Benstetter, G. Lei

Tensile stress-driven cracking of W fuzz over W crystal under fusion-relevant He ion irradiations

Nuclear Fusion, vol. 60, no. 4

2020

DOI: 10.1088/1741-4326/ab71bb

Abstract anzeigen

Although W fuzz is formed in the divertor region of the fusion reactor, no theory may clearly explain the W fuzz growth mechanism. In this study, we observe the growth process of W fuzz over W crystal under ITER-relevant He ion irradiations. We propose the tensile stress-driven cracking of nano-structured fuzz during the initial growth of W fuzz. We demonstrate that the existence of tensile stress is due to the swelling of He nano-bubbles in the fuzz. After this cracking, the W fuzz breaks away from the planar network and grows over the W surface, where the micro-stress in the W surface layer acts as the driving force.

NachhaltigElektrotechnik und MedientechnikIQMA

Zeitschriftenartikel

W. Ni, L. Liu, Y. Zhang, C. Niu, H. Fan, G. Song, D. Liu, Günther Benstetter, G. Lei

Effect of intermittent He/D ion irradiations on W nano-fuzz growth over W targets

Vacuum, vol. 173, no. March

2020

DOI: 10.1016/j.vacuum.2019.109146

Abstract anzeigen

The intermittent He/D ion irradiations of polycrystalline W have been performed at the ion energy of 50 eV by changing the time of the single irradiations and the irradiation temperature. All irradiated W specimens have been observed by scanning electron microscopy, and the effect of intermittent He/D ion irradiations on the W fuzz growth has been analyzed. The W fuzz growth over W targets does not show the clear dependence on the intermittent He/D ion irradiations, where the He/D ion fluence of the single irradiations typically varies from 5.0 × 1024 to 2.5 × 1025/m2. However, a slight change in the W surface temperature during the single He ion irradiations significantly affects the W fuzz growth rate. Analysis indicates that W fuzz growth is significantly affected by the total He ion fluence varying from 5.0 × 1024 to 5.0 × 1025/m2 and the irradiation temperature varying from 1100 to 1450 K. This current study will play a crucial role in understanding the W fuzz growth under the periodic He/D ion irradiations of W divertor in fusion reactors, such as ELMs.