Visible light emission induced by Krq+ (4 ≤ q ≤ 9) ions colliding with the Cu surface

Abstract In this paper, we report visible light emission from 320 keV Kr q+ (4 ≤ q ≤ 9) ions on the Cu target. The wavelength range measured is from 300 nm to 656 nm. Two Cu I spectra deriving from different initial states and one Kr I line are detected. Specifically, the two Cu I lines belong to transitions 3d 10 4p( 2 P 0 3/2 ) − 3d 10 4s ( 2 S 1/2 ) at 324.78 nm (A) and 3d 10 4p( 2 P 0 1/2 ) − 3d 10 4s( 2 S 1/2 ) at 327.42 nm (B), respectively, and the photon yield ratio of spectra lines (A) and (B) are about 2:1. The Kr I line belongs to transition 4s 2 4p 5 ( 2 P 0 3/2 )11d 2 [3/2] 0  − 4s 2 4p 5 ( 2 P 0 3/2 )5p 2 [1/2] at 486.12 nm (C). In addition, the experimental results show that the photon yields of all lines are increasing with the charge state increase.