Spectroscopic measurements of ion source divergence in a high-power applied-B ion diode

Summary form only given. State-of-the-art space- and time-resolved visible spectroscopy measurements have been performed in the anode-cathode (AK) gap of the high-power applied-B ion diode of the particle beam fusion accelerator II (PBFA II) to study the energy of ions and atoms transverse to the direction of acceleration. The line profiles show strong broadening and shifting in general. These profiles can be affected by mechanisms such as Stark shifting. Stark broadening, Zeeman splitting, opacity effects, instrument broadening, and Doppler broadening. One goal of this study is to extract the Doppler broadening of ion and atom lines in order to obtain the ion beam divergence at the ion source. The readily observable Li I 2s-2p (6708 /spl Aring/) emission in the AK gap is examined with both passive and active lithium ion sources. The time of arrival at different radii indicates fast (/spl sim/50 cm/ /spl mu/s) Li I propagation away from the anode into the AK gap.