Transmission of highly charged ions through nanocapillaries of noncircular cross sections

28th International Conference on Photonic, Electronic and Atomic Collisions

Zhang, H.Q.^1,2 ; Akram, N.^1 ; Soroka, I.L.^1 ; Trautmann, C.^3 ; Schuch, R.^1

Physics Department, Stockholm University, Stockholm

S-10691, Sweden^1

School of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu

730000, China^2

GSI Helmholtzzentrum Darmstadt, Germany^3

关键词: Geometrical patterns;    Geometrical shapes;    Highly charged ions;    Noncircular cross section;    Rectangular geometry;    Rectangular-shaped;    Trajectory simulation;    Transverse energy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/488/1/012035/pdf
DOI  :  10.1088/1742-6596/488/1/012035

来源: IOP

【 摘 要 】

We report on effects from the geometrical shape of the guiding channels on the ion transmission profile. We find that capillaries of rhombic cross section produce rectangular shaped ion transmission profiles and, vice versa, capillaries of rectangular geometry give a rhombic beam shape. Our trajectory simulations for the incidence of 14-keV Ne7+ions give clear evidence that the observed effect is due to the image forces experienced by the transmitting ions. They gain transverse energy due the image charge attraction towards the inner surfaces of the capillary. This leads to a defocusing of the ions leaving the capillaries. Due to the blocking of large deflection angles at the exit of the capillary, the transmitted ion beam is tailored into certain geometrical patterns.