[jkelleyrtp]

Or even crazier stuff like wakefield accelerators and petawatt lasers. At this point the LHC is like ITER - advancements to the foundational technology have jumped leaps and bounds yet we're still stuck with a huge multi-billion dollar machine running on fairly outdated tech.

[Random_ernest]

That is simply not true, the plasma wakefield accelerators are really a rather new technique but they are NOT meant to be used at such high energies, but rather for small experiments. Also (as far as I know), while they do have vastly superior energy gain per meter, you simply can't concatenate several of them (as you do with SRF cavities). So at the current state, if you want to reach TeV of colliosion energy, SRF is the only way to go.

Current plasma wakefield accelerators are in GeV range, we need TeV.