Mean velocity of 5d56p excited tungsten atoms sputtered by Kr+ ion bombardment

Visible emission spectroscopy was conducted for atoms sputtered from tungsten surfaces under Kr+ ion irradiation (33–60 keV). A number of WI lines were observed in the wavelength of 360–490 nm. The emission intensity of the WI line at 400.88 nm was measured as a function of the distance from the surface. The mean normal velocity of W∗(5d5(6S)6p 7P4) atoms was measured by analyzing the exponential decay curves. No remarkable change in the velocity was found for different projectile energies. The average velocity was 5.6 ± 1.7 kms−1.

► Spectroscopy of sputtering atoms on W surfaces under Kr ion irradiation was conducted.
► Mean velocity of the excited atoms was measured by an optical method.
► The mean velocity was almost independent on the projectile kinetic energy.