A study of on-line gas cell processes at IGISOL

The laser ion source at the IGISOL facility, Jyväskylä, has been used to study the effects of the passage of a primary beam through an ion guide via the dynamic time profiles of yttrium and related molecular compounds. The accessibility of a neutral fraction for laser ionization is shown to be restricted to the nozzle region in the presence of a weak plasma. The survival of this neutral fraction cannot be explained by recombination of the buffer gas alone and perhaps indicates a suppression of the transport of ions due to a plasma-generated electric field. The concept of a competition between the processes that create and destroy the ion of interest is used to explain the different trends in the ratio of yttrium to yttrium oxide following the extraction of a stopped primary beam of 89Y21+ in both helium and argon buffer gases.