Are diffraction effects essential for ion interaction with a solid surface when the ion has an energy in the range ~1 keV to ~1 MeV (typical ion energies employed in ion spectroscopies)? Estimate at what energy the de Broglie wavelength of the ion is comparable to the interatomic distance in a solid (~3 A). Does this energy fall into the above range? As an example, consider He+ ions.

Are diffraction effects essential for ion interaction with a solid surface when the ion has an energy in the range ~1 keV to ~1 MeV (typical ion energies employed in ion spectroscopies)? Estimate at what energy the de Broglie wavelength of the ion is comparable to the interatomic distance in a solid (~3 A). Does this energy fall into the above range? As an example, consider He+ ions.