Investigation of different oven types for sample evaporation in the CAPRICE electron cyclotron resonance ion source

The operation of the CAPRICE-type electron cyclotron resonance ion source (ECRIS) at the high charge state injector of GSI requires a great variety of different ion species (between Z=3 and Z=92) to be delivered to the accelerator. As most of the elements have to be produced from nongaseous materials, oven evaporation has become an elaborate and routinely used technique at GSI. Besides an evaporator for high vapor pressure materials (T⩽300 ° C ) a standard oven system is used for temperatures between 600 °C and 1500 °C. Several modifications of this standard oven have been developed to adapt it to the operating conditions for different materials. The respective characteristics are described and operational experiences are reported. In order to extend the available temperature regime up to 2000 °C, a new type of oven is being developed which completely avoids any ceramics in its high temperature zone. Thus the number of materials accessible for evaporation is considerably extended. First experiences obtained with this high temperature oven are presented.