Atomistic simulation of defect formation and structure transitions in U-Mo alloys in swift heavy ion irradiation

Journal of Nuclear Materials. 2017. Vol. 495. P. 111–117.

Kolotova L., Starikov S.

In irradiation of swift heavy ions, the defects formation frequently takes place in crystals. High energy

transfer into the electronic subsystem and relaxations processes lead to the formation of structural

defects and cause specific effects, such as the track formation. There is a large interest to understanding

of the mechanisms of defects/tracks formation due to the heating of the electron subsystem. In this work,

the atomistic simulation of defects formation and structure transitions in U-Mo alloys in irradiation of

swift heavy ions has been carried out. We use the two-temperature atomistic model with explicit account

of electron pressure and electron thermal conductivity. This two-temperature model describes

ionic subsystem by means of molecular dynamics while the electron subsystem is considered in the

continuum approach. The various mechanisms of structure changes in irradiation are examined. In

particular, the simulation results indicate that the defects formation may be produced without melting

and subsequent crystallization. Threshold stopping power of swift ions for the defects formation in

irradiation in the various conditions are calculated.

Keywords: атомистическое моделирование, atomistic simulations, Swift heavy ion irradiation, U-Mo alloys, облучение быстрыми тяжелыми ионами, сплавы U-Mo