FAST NEUTRON DAMAGE STUDIES ON NdFeB MATERIALS∗

Many materials and electronics need to be tested for the radiation environment expected at linear colliders (LC) since both accelerator and detectors will be subjected to large fluences of hadrons, leptons and γ’s over the life of the facility[1]. While the linacs will be superconducting, there are still many uses for NdFeB in the damping rings, injection and extraction lines and final focus. Our under-standing of the situation for rare earth, permanent mag-net materials was presented at PAC03[2]. Our first mea-surements of fast neutron, stepped doses at the UC Davis McClellan Nuclear Reactor Center (UCD MNRC) were presented at EPAC04[3]. We have extended the doses, included other manufacturer’s samples, and measured in-duced radioactivities which are discussed in detail