IN-PILE ARRANGEMENTS OF REACTOR-BASED RTB FACILITIES

Two Radioactive Ion Beam facilities are projected at high-flux reactor s: PIAFE at the Institut Laue Langevin in Grenoble and the Munich Fiss ion Fragment Accelerator at the FRM-II in Garching. Both will operate with a ''nuclear heated'' target-ion-source assembly (fission rate app roximate to 10(14) s(-1)) in an in-pile position in a neutron flux of the order 10(14) cm(-2) s(-1). The expected beam intensities are sever al orders of magnitude higher than those of existing ISOL facilities w hich use thermal neutron-induced fission. The major difference between the in-pile parts of the projects is the type of beam tube: PIAFE wil l use a single-ended tube where target change and ion extraction are d one to the same side - at the FRM-II a tube with access from both side s will be used, allowing a spatial decoupling of target handling and i on extraction. Different methods to master the new technical challenge s arising from the high neutron flux are discussed.