The IFMIF-EVEDA challenges in beam dynamics and their treatment

One major system of the IFMIF project (International Fusion Materials Irradiation Facility) is its two accelerators producing the neutron flux by accelerating deuteron particles up to 40 MeV against a lithium target. In the first phase called EVEDA (Engineering Validation and Engineering Design Activity), a full scale prototype accelerating particles up to 9 MeV is being studied and constructed in Europe, to be installed in Japan.Two unprecedented performances are required for the IFMIF-EVEDA accelerators: very high power of 5 MW and very high intensity of 125 mA CW. This leads to numerous unprecedented challenges in beam dynamics design and optimisation: harmful losses even for those less than 10−6 of the beam, non-linear dynamics induced by very strong space charge forces, difficulties for equipment and diagnostic implementations in the high compact structure, need of specific tuning strategies in this context.These issues are highlighted in this article, and the ways in which they are addressed are detailed.