You don't understand. ITER will RESEARCH, how existing materials withstand in real fusion reactor, and gather parameters of real fusion reactor, so other science facilities will have benchmarks.
ITER is fundamentally unable to replicate the conditions that materials will be subjected to in an actual commercial fusion reactor. It cannot achieve the same cumulative neutrons dose that a real reactor can experience. It will not be able to answer the questions that need to be answered to prove out the materials for first walls or blankets, and it will not be able to establish reliability metrics for these structures.
For this reason, there has long been a call for a FNSF. This facility is likely to be needed to establish designs for components that would go into the putative successor to ITER (DEMO).
ITER fails in at least two ways. First, the intensity of neutron radiation at the first wall is far too low for a viable commercial reactor. It cannot simulate the heat load a commercially viable breeding module would encounter. Second, ITER cannot operate for more than a few weeks, so it cannot simulate the integrated radiation load a commercial first wall would have to be able to withstand. It also cannot operate with enough blanket modules, for long enough, to move the designs down experience curves for reliability growth to occur so they are sufficiently robust for a commercial reactor (this is a huge looming problem, as they will be very difficult to repair.)
Abdou at UCLA has been beating the drum for a FNSF to actually address these issues. He's been beating this drum for DECADES.
> the intensity of neutron radiation at the first wall is far too low for a viable commercial reactor
Source? Proofs? Sorry, for me this looking as just Your opinion.
> Second, ITER cannot operate for more than a few weeks
This is just not important at all now. That what I mean, said You don't understand physics.
- NOWHERE at Earth possible to recreate exact radiation environment of Jupiter orbit for YEARS, need to test radiation capable computer environment for space probes.
What really doing? After first probes measured parameters of environment, at Earth built test benches, consisting of few throttle-able sources, so they give approximate spectrum, very like near Jupiter, but could do year dose in few hours and could easy be switched off, to make manipulations with tested samples.
So now, I even know guys, who touched exposed chips and running real world software on them, and real computers in Jupiter/Mars missions, working much longer than need for mission (BTW, first samples tested at Earth, where not reliable).