Boron Isotope Fractionation During Prolonged Ion Bombardment

Dynamic Monte Carlo simulation is used to explore the B isotope sputtering during 1 keV Kr ion irradiation. It is found that at both zero and high fluences the light isotope is preferentially ejected in the near-normal direction; meanwhile, there is a low fluence (1.4x10¹⁵ ions/cm²), at which the isotope fractionation is independent of the emission angle in the nearly whole angular range.