SOME SPECIAL MICROWAVE STRUCTURES FOR ECRIS

The studies and the experimental work for constructing an electron cyc lotron resonance ion source (ECRIS) for the new tritium linear acceler ator (TRILAC) at the Institute of Atomic Physics are presented. The ab sence of consumable parts, the low neutral pressure, and the high ioni zation efficiency with light elements make ECRIS very attractive for t his accelerator. Some special configurations for the microwave system and for the plasma chamber are presented. A suitable modified structur e of a power helix-type traveling wave tube (glass envelope with helix ) in conjunction with its corresponding lateral rectangular waveguide tapers is presented. Application of an iris-loaded circular waveguide (traveling wave structure of a linear accelerator) as a slow wave stru cture is also under study. Problems like unstable tuning and arcing, w hich are encountered in the known structures, could be avoided by usin g slow wave structures of traveling wave type.