Speaker
Description
The CAPRICE ECRIS installed at the High Charge
Injector (HLI) of GSI produces highly charged ion
beams from gaseous and metallic elements. A high
demand of metal ions comes from the nuclear
physics, material re-search, and Super Heavy
Element group (SHE), and the most requested
element, besides 50Ti, is 48Ca. When this chemical
reactive material is deposited inside the plasma
chamber at internal components the stability can be
com-promised. Furthermore, it is difficult to find a
working point to guarantee a long-term stability as
the oven re-sponse time and the reaction of the
ECRIS are relatively slow. The monitoring by using an
Optical Emission Spectrometer (OES) facilitates
immediate reactions when-ever plasma instabilities
occur. For this reason, a real-time diagnostic system
based on an OES has been in-stalled at the ECRIS at
HLI for routine operation during the beam-time 2020.
The measured spectra revealed a parasitic oven
heating by coupled microwaves often com-promising
the ion source performance. Therefore, a tung-sten
grid has been installed to shield the oven orifice from
the coupled microwaves. The results in terms of 48Ca
beam intensity and stability are reported here.