“…106 In any case, a W layer of sufficient thickness should be able to effectively protect the TE device against plasma-induced gas implantation but not against He or hydrogen isotope formation within the TE materials and device components due to transmutation by neutron irradiation, which will be elaborated in detail in the next sub-section. 107,108 However, the disadvantage of high Z armour materials over their low Z counterparts is that if any of the armour materials fall into the plasma, high Z materials are more effective at quenching the plasma and stopping the fusion reaction. 8 When using a high Z armour material such as W, the adhesion between the armour material and the reactor wall becomes even more crucial.…”