Visible light emission from slow highly charged ions transmitted through aNi microcapillary

Interaction of slow highly charged ions (HCI) with a thin microcapillary fo il was studied for the first time through measurements of visible light emi tted from the ions downstream of the foil. The microcapillary was employed so that ions which capture electrons in high Rydberg states may not violent ly collide with the surface in spite of the image acceleration. The wavelen gth range measured was from 300 nm to 600 nm. Some strong lines were found attributable to Delta n = 1 transitions resulting from a single electron ca pture into states with n(i) similar to Q and with a large angular momentum.