Do most people know that alchemy has been realized in modern physics? Lead has indeed been converted to gold (at terrible efficiency)!
One of the issues that I sort of sniffed out in the field is as a whole they are pushing for higher and higher peak energy without really looking to improve beam quality, that is, everything below the peak. Like this paper (which an old colleague is an author on!! Congrats to him) is actually pretty good on the divergence as 1mrad (mili radians) but the energy spread is 15% around the peak, which is good for some things, but there are experiments with linacs that require percent spreads less than a percent. Now, you can probably "filter" out the energies you don't want out of the beam to make it even more monoenergetic, but for example this beam has tens of picocoloumbs. Assuming (very generously, haven't read beyond the abstract yet) that most of the tens of pico they report is in that 15% spread, 1% means you might be dipping into less than a picocoloumb territory on target for your experiment, which might not give enough dose for what you need to probe or otherwise do.
Anyway, in terms of the field, this work is fantastic, and generally Howard and Jorge are fantastic scientists (never met Jorge but Howard's a real decent man), but this is the cream of the crop of what we as a field can currently do. I feel like getting to the point where we give the traditional accelerator types a run on their money is still a few years out.
Is the beam quality a fundamental limiting factor, or is it solvable (at least theoretically).
It sees they're going for the get the energy up and solve the beam characteristics later approach
My understanding of most particle accelerators is that they accelerate their subjects directly with fields, either oscillating or steady. Wakefield accelerators use a combination of fields (the laser pulse) and other particles (the "stationary" ions). My suspicion is that the ion background introduces enough noise/chaos into the process that it would be a great effort to make the output more monoenergetic and retain total brightness. But I dunno, I always found particle physics a little tedious and didn't pay as much attention as I could have.
At least frequency noise is inherent for any accelerator where the particles stay for a very short time.
Seaborg did it in 1980 but with bismuth.
“It would cost more than one quadrillion dollars per ounce to produce gold this way.” And that’s in 1980 dollars :)
Or in pop-Zen terms, don’t mistake the finger for the moon.