PSI issues at plasma facing surfaces of blankets in fusion reactors

Important PSI issues for the first wall of blankets in fusion reactors are reviewed. Present understandings and remaining issues for particle loads (fast neutral, thermal ions, and energetic alpha particle ripple losses), and evaluation of low-activation structural materials (RAF, V-alloys, and SiCf/SiC) and tungsten as first-wall armor (including the effect on tritium breeding ratio of blankets) are explained. If the characteristics of particle load to the first-wall evaluated for ITER-FEAT is similar to DEMO and future reactors, erosion rates of the blanket first-wall made by low-activation materials are not acceptable considering their thickness. For this case, armor materials such as W or some protection methods such as in-situ coatings of low Z materials could be needed. Blistering and H/He embrittlement are also important issues to consider. Possible effects of the first wall on core plasma performance are briefly discussed in terms of hydrogen isotope recycling and reflection of synchrotron radiation.