In-pile arrangements of reactor-based RIB facilities

Two Radioactive Ion Beam facilities are projected at high-flux reactors: PIAFE at the Institut Laue Langevin in Grenoble and the Munich Fission Fragment Accelerator at the FRM-II in Garching. Both will operate with a "nuclear heated" target-ion-source assembly (fission rate ≈ 10¹⁴ s^-1) in an in-pile position in a neutron flux of the order 10¹⁴ cm^-2 s^-1. The expected beam intensities are several orders of magnitude higher than those of existing ISOL facilities which use thermal neutron-induced fission. The major difference between the in-pile parts of the projects is the type of beam tube: PIAFE will use a single-ended tube where target change and ion extraction are done to the same side - at the FRM-II a tube with access from both sides will be used, allowing a spatial decoupling of target handling and ion extraction, Different methods to master the new technical challenges arising from the high neutron flux are discussed.