Neutron irradiation effects on tungsten materials

Hasegawa, Akira; Fukuda, Makoto; Nogami, Shuhei; Yabuuchi, Kiyohiro

doi:10.1016/j.fusengdes.2014.04.035

Cited by 189 publications

(109 citation statements)

References 22 publications

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“…Unlike in the first set, the orientation of the dumbbells is not limited to . In the second set, parallel configurations of [111], , [1][2][3][4][5][6][7][8][9][10][11], and [-111] dumbbells are allowed. Hence there are 4x83 = 332 parallel clusters in which 254 are unique.…”

Section: Larger Clustersmentioning

confidence: 99%

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Ab initio study of interstitial cluster interaction with Re, Os, and Ta in W

Setyawan

Nandipati

Kurtz

2017

Journal of Nuclear Materials

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The stability of tungsten self-interstitial atom (SIA) clusters is studied using first-principles methods. Clusters from one to seven SIAs are systematically explored from 1264 unique configurations. Finite-size effect of the simulation cell is corrected based on the scaling of formation energy versus inverse volume cell. Furthermore, the accuracy of the calculations is improved by treating the 5p semicore states as valence states. Configurations of the three most stable clusters in each cluster size n are presented, which consist of parallel [111] dumbbells. The evolution of these clusters leading to small dislocation loops is discussed. The binding energy of size-n clusters is analyzed relative to an n → (n-1) + 1 dissociation and is shown to increase with size. Extrapolation for n > 7 is presented using a dislocation loop model. In addition, the interaction of these clusters with a substitutional Re, Os, or Ta solute is explored by replacing one of the dumbbells with the solute. Rhenium and Os strongly attract these clusters, but Ta strongly repels. The strongest interaction is found when the solute is located on the periphery of the cluster rather than in the middle. The magnitude of this interaction decreases with cluster size. Empirical fits to describe the trend of the solute binding energy are presented.

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Section: Larger Clustersmentioning

confidence: 99%

“…Therefore, Re, Os, and to a lesser extent Ta, are the main concerns in regards to the effects of transmutation products on tungsten properties degradation. These solutes will eventually lead to the formation of brittle intermetallic phases that is detrimental to the mechanical properties of tungsten [7,8].…”

Section: Introductionmentioning

confidence: 99%

Ab initio study of interstitial cluster interaction with Re, Os, and Ta in W

Setyawan

Nandipati

Kurtz

2017

Journal of Nuclear Materials

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“…Hasegawa and co-workers [23,24] pioneered such detailed studies in pure W, irradiated by fission neutron irradiations (0.09e1.54 dpa, 700e1100 K). In the low-dose (<0.5 dpa) and lowtemperature (T 800 K) regime, the visible defect species were mostly voids as well as small numbers of loops.…”

Section: Introductionmentioning

confidence: 99%

In-situ TEM studies of 150 keV W+ ion irradiated W and W-alloys: Damage production and microstructural evolution

et al. 2016

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a b s t r a c tIn-situ irradiations with 150 keV W þ ions have been performed on W and W-5wt.% (Re; Ta; V) alloys in a comprehensive study of the influences of irradiation temperature T irr , dose, alloying elements and grain orientations on radiation damage production and microstructural evolution. For T irr between 30 K and 1073 K, the first observable defects in pure W appeared at doses 0.01 dpa, and were most likely vacancy loops, with Burgers vectors predominantly of type b ¼ ½ <111>. With increasing T irr , the retained defect concentration decreased strongly and the maximum cluster size increased from~1300 point defects at 30 K to~2300 point defects at 1073 K. At all irradiation temperatures, the evolution of damage microstructures with dose from 0.1 to 1.0 dpa involved defect cluster migration, with mutual elastic interactions often leading to spatial inhomogeneities and loop reactions. In pure W, spatial ordering of loops was observed at doses >0.4 dpa and T irr ! 773 K in grains close to z ¼ <001>. No such ordering was found in similar grain orientations for the W-(Re; Ta) alloys, but it was found in the non-z ¼ <001> grains. Post-irradiation analysis on W and W-5 wt% (Re; Ta) at 1.0 dpa showed that ½ <111> and <100> loops of both vacancy and interstitial type were present, at number densities~10 15 loops m À2 . In all cases ½ <111> loops were dominant, the fraction of these with interstitial nature increased with T irr , and the proportion of <100> loops decreased with increasing T irr . Compared with pure W, microstructures in the W-(Re; Ta) alloys exhibited higher loop number densities and evolved more quickly with increasing dose towards damage saturation.

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“…The irradiation effect of neutron has been investigated by several papers [7,8]. However, neutron source is too precious to obtain and long time consuming to achieve a certain damage level.…”

Section: Introductionmentioning

confidence: 99%