Optical emission from the interaction of highly charged Xeq+ (6 ≤ q ≤ 23) ions with GaAs surface

This paper reports the measurement of visible light emission in the collisions of slow (V ∼ 0.38 VBohr) highly charged Xeq+ (6 ≤ q ≤ 23) ions with GaAs surface. The experimental results include Ga I lines from the 4d 2D3/2 and 5 s 2S1/2 to the 4p 2P1/2,3/2 states and Ga II lines belonged to the electron transitions 4p21D2 → 4s4p 1P1, 4s5s 1S0 → 4s4p 1P1 and 4s4f 1F3 → 4s4d 3D3. The measurement on the projectile charge state dependences of Ga II at 270.20, 277.90, 426.20 nm and Ga I at 287.65, 294.55, 403.55, 417.35 nm lines is presented. It is concluded that the photon yields increase with charge state in the same way as the potential energy increases and the potential energy is the driving force for optical emission of excited Ga atoms and Ga+ ions.