Vacancy annealing in irradiated tungsten

Vacancy annealing in irradiated tungsten by Dexter A. Jeannotte Download PDF EPUB FB2

In contrast, in neon ion-irradiated tungsten, irradiation-induced vacancy-type defects were observed to aggregate significantly at ∘ C and ∘ C. In addition, the large vacancy clusters formed by the aggregation survived even after annealing at ∘ : A.

Yabuuchi, M. Tanaka, A. Kinomura. Electron diffraction contrast experiments have been performed to crystallographically characterize the dislocation loops which form during °C annealing of neutron-irradiated tungsten.

These experiments show that the loops are essentially pure edge in orientation, lying on or near {} habit planes and having a /2 Burgers by: The thermal evolution of vacancies and vacancy clusters in tungsten (W) has been studied.

W () single crystals were irradiated with keV hydrogen (H) ions to a low damage level ( × 10 − 3 dpa) at K and then annealed at temperatures in the range of – : M. Zibrov, M. Zibrov, M. Zibrov, W. Egger, J. Heikinheimo, J. Heikinheimo, M.

Mayer, F. Tuomisto, F. In Chapter–1 of this timely book, radiation damage in vanadium, niobium, molybdenum and tungsten is discussed at the atomic level; treating – for instance - third-stage recovery in terms of self-interstitials being mobile traps for - predominantly - vacancies. Higher recovery stages are treated by using various techniques, such as: electrical resistivity, electron microscopy, positron.

Evolution of vacancy-type defects has been investigated in undamaged and copper ion pre-damaged tungsten exposed to low-energy and high-flux helium plasma (60 eV, 1 × 10 22 He/m 2 s).

The results measured by Doppler broadening positron annihilation spectroscopy (DB-PAS) indicate that helium-vacancy complexes generate due to intense self-trapping in the undamaged tungsten after helium Author: Shiwei Wang, Wangguo Guo, Yue Yuan, Ning Gao, Xiuli Zhu, Long Cheng, Xingzhong Cao, Engang Fu, Liqun.

Annealing, consisting of the growth and eventual elimination of the clusters, is observed to occur in two stages, one at temperatures below °C and one at temperatures above °C, which are interpreted as being due to interstitial and vacancy migration, by: This statement is also in agreement with Y.-W.

Kim, J.M. Galligan l Annealing study of thermal neutron irradiated tungsten n o o-4 O 5 3 vc. 5 u 2 " l - Spec E-2 a E-4 25 ANNEALING TEMPERATUREt •C) Fig. by: 5. Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, °C, W+/cm2) with temperatures of, and °C, from to 8 h, was followed by ex.

The self-assembly nanocone structures on the surface of polycrystalline tungsten were created by He+ ion irradiation and then annealing, and the resulting topography and morphology were. Three non-irradiated (0 dpa) tungsten samples also were exposed to deuterium plasma at three different temperatures, and the TPE exposure and TDS procedures were repeated (once for °C, three times for °C sample, and twice for °C) to compare defect-annealing effects on deuterium retention in non-irradiated (0 dpa) by: 6.

The interaction between deuterium and radiation-induced point defects in tungsten and the stages of their transformation and annealing are investigated by means of thermal-desorption spectroscopy.

Primary defects, mainly vacancies, are created using keV D+ ions at room temperature. In investigating the evolution of radiation-induced defects, irradiated samples are Cited by: 2.

@article{osti_, title = {High temperature annealing of ion irradiated tungsten}, author = {Ferroni, Francesco and Yi, Xiaoou and Arakawa, Kazuto and Fitzgerald, Steven P.

and Edmondson, Philip D. and Roberts, Steve G.}, abstractNote = {In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate.

Positron lifetime and Doppler broadening measurements have been performed on alpha-irradiated tungsten to study the evolution of defects during isochronal annealing from °C to °C.

Vacancy-impurity complexes dissociate at the earlier stages and release the vacancies. Monovacancies start migrating at °C. The vacancy clusters coarsen Cited by:   Positron annihilation lifetime spectroscopy (PALS) was applied to study the annealing of radiation-induced defects in polycrystalline tungsten (W) irradiated with MeV protons at °C up to a fluence of 5 × 10 15 p/cm 2.

Three components were observed in the measured spectra: short-lifetime of ps (positron annihilation in the defect-free W lattice), medium-lifetime of ∼ Cited by: 5.

CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority Francesco Ferroni, Xiaoou Yi, Kazuto Arakawa et al., High temperature annealing of ion irradiated tungsten, Acta Mater. 90 () – Abstract Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in tungsten irradiated at reactor ambient tempeaature, ˜ 70°C.

Annealing, consisting of the growth and eventual elimination of the clusters, is observed to occur in two stages, one at temperatures below °C and one at. Annealed tungsten wire has been reactor-irradiated to a dose of 10 17 n. (> 1 MeV), and specimens for field-ion microscopy prepared from the wire.

Vacancies could be identified in certain regions of the field-ion microscope image, and the size and shape of small clusters of vacancies could be found by careful field-evaporation. The formation of the pores can be due to the aggregation of the irradiation-induced vacancies and gas bubbles [20, 21].

Post-irradiation thermal annealing in vacuum at °C did not cause any obvious change to the surface morphology of the 1 × 10 17 Ar + ions cm −2 irradiated sample (see figure 1(c)).

for neutron-irradiated tungsten in the fast neutron reactor JOYO at irradiation temperatures of ° C [26, 27]. In this work, the estimated value of f max = 0. 01 will be used in the.

Formation of tungsten oxide nanowires by ion irradiation and vacuum annealing Xu-Dong Zheng1,2, Feng Ren1, Heng-Yi Wu1, Wen-Jing Qin1 and Chang-Zhong Jiang1 1School of Physics and Technology, Center for Ion Beam Application, Center for Electron Microscopy and Hubei Nuclear Solid Physics Key Laboratory, Wuhan University, WuhanPeople’s Republic ofCited by: 1.

Transmission electron microscope is widely used to investigate the defects induced by heavy ion irradiation and deuterium plasma exposure in tungsten, however, results differ greatly between in situ and near-bulk irradiation experiments.

Here we adopt the back-thinned electropolishing and re-electropolishing method to study the microstructure in the peak damage region of heavy ion Author: Wangguo Guo, Shiwei Wang, Lin Ge, Engang Fu, Yue Yuan, Long Cheng, Guang-Hong Lu.Tungsten is the front-runner candidate for building the plasma-facing armour components for future fusion reactors.

However, in-service irradiation by fusion-neutrons and helium will create Author: Suchandrima Das.Vacancy-type defects created by helium implantation in tungsten and their impact on the nano-hardness characteristics were investigated by correlating the results from the positron annihilation spectroscopy and the nano-indentation technique.

Helium implantation was performed at room temperature (RT) and at an elevated temperate of °C. Also, the effect of post-annealing of the RT Cited by: