Challenges of Target and Irradiation Diagnostics of the IFMIF-DONES Facility

IFMIF-DONES will be a first-class scientific infrastructure consisting of an accelerator-driven neutron source delivering 1e17 n/s with a broad peak at 14 MeV. Such neutron flux will be created by impinging a continuous wave 125 mA, 40 MeV, 5 MW deuteron beam onto a liquid Li jet target, circulating at 15 m/s. Material specimens subjected to neutron irradiation will be placed a few millimeters downstream. Some of the most challenging technological aspects of the facility are the Diagnostics to monitor the Li jet, beam parameters on target, and characterization of the neutron irradiation field, with transversal implications in the scientific exploitation, machine protection and safety. Multiple solutions are foreseen, considering among others, Li jet thickness measurement methods based on optical metrology and millimeter-wave radar techniques, Li electromagnetic flowmeters, beam footprint measurements based on residual gas excitation, online neutron detectors such as SPNDs and micro-fission chambers, as well as offline neutron fluence measurements by activation foils or spheres. This contribution provides an overview of these aspects and the associated R activities.