The identification of vacancy loops in irradiated tungsten

Microstructural evolution of irradiated tungsten: Ab initio parameterisation of an OKMC model

“…One must add also that more recent ab initio calculations using the software PLATO are in contradiction with our finding as the authors of [25] obtained a positive binding energy of 0.41 eV for the di-vacancy binding energy. It is a little difficult at first to conciliate our finding that di-vacancies are not stable with the vacancy loops observed by Transmission Electron Microscopy [84][85][86][87][88] or the voids observed in displacement cascades by FIM [89]. However, in the case of displacement cascades, lots of vacancies are created in the core of the damaged region, which are already very close to each other, and thus the formation of vacancy clusters can take place by immediate agglomeration of vacancies without going through the process of first creating a divacancy, which will be joined by a vacancy to form a tri-vacancy and so on.…”

The metallurgical enhancement of type II superconductors

“…This, however, contradicts the evidence previously quoted. Recent work by Buswell (1970), who studied neutron irradiated tungsten by electron microscopy and field ion microscopy, shows that less than 10% of the damage was in the form of dislocation loops visible in the electron microscope. At least 80% of the damage was in the form of vacancy clusters, of about 10 vacant lattice sites, visible only in the field ion microscope.…”

Object kinetic Monte Carlo simulations of irradiated tungsten for nuclear fusion reactors

“…It is worth mentioning that the binding energy for two vacancies is negative, i.e., they repel each other [66]. Derlet et al [96] loops [104][105][106][107]. Nevertheless, the irradiation produces highly concentrated damage cascades that favour a direct formation of large vacancy clusters, without a previous formation of divacancies [66].…”