Atomistic simulation of ion track formation in UO2

Area of Science:

• Materials Science
• Nuclear Engineering
• Computational Physics

Background:

• Swift heavy ions induce damage in materials, crucial for nuclear applications.
• Understanding track formation in uranium dioxide is vital for nuclear fuel performance.
• Previous models often simplified the complex interactions during ion irradiation.

Purpose of the Study:

• To atomistically simulate track formation in uranium dioxide induced by swift heavy ions.
• To investigate the distinct mechanisms governing surface versus bulk track formation.
• To determine the threshold stopping power for track initiation.

Main Methods:

• Utilized a two-temperature atomistic model.
• Employed molecular dynamics for the ionic subsystem.
• Applied a continuum approach for the electron subsystem, including electron pressure and thermal conductivity.

Main Results:

• Simulations revealed that surface track formation mechanisms differ from bulk track formation.
• The study successfully estimated threshold values for stopping power required for track formation.
• The two-temperature model provided detailed insights into ion-matter interactions.

Conclusions:

• The distinct mechanisms for surface and bulk track formation in uranium dioxide have been elucidated.
• Threshold stopping power values provide critical data for predicting ion track behavior.
• The employed two-temperature model is effective for simulating ion-induced phenomena in materials.