Dynamical effects in the interaction of ion beams with solids
Ryan Hatcher1, Matthew Beck, Alan Tackett
1Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
Physical Review Letters
|March 21, 2008
Summary
Dynamical simulations using time-dependent density-functional theory reveal ion stopping power in silicon. This method accurately predicts oscillatory atomic number dependence without free parameters, improving upon static models.
Area of Science:
- Physics
- Materials Science
- Computational Chemistry
Background:
- Traditional stopping power calculations rely on simplified models with free parameters.
- These models often treat electron gas as homogeneous and atomic interactions as static.
Purpose of the Study:
- To develop a parameter-free method for calculating ion stopping power in solids.
- To investigate the role of electron dynamics and density nonuniformities in ion stopping power.
Main Methods:
- Dynamical simulations of ions channeled in silicon.
- Application of time-dependent density-functional theory (TDDFT).
- TDDFT calculations for a homogeneous electron gas.
Main Results:
- Calculated stopping powers show excellent agreement with experimental oscillatory dependence on atomic number.
- TDDFT accurately reproduces observed data without requiring free parameters.
- Demonstrated the necessity of electron dynamical response and density nonuniformities.
Conclusions:
- TDDFT provides a robust, parameter-free approach to calculating ion stopping power.
- The findings challenge previous assumptions about electron gas behavior in stopping power calculations.
- This work offers a more accurate theoretical framework for understanding ion-matter interactions.
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