Dr. Larson's Blog

Electron Cooling of Muons


Cooling Muons 1. I earned a Ph.D. in accelerator physics back in 1986. My thesis experiment involved the design and successful operation of a two and a half million volt, near ampere intensity, electron beam accelerator. That accelerator was intended to be used to overlap its electron beam on the top of antiproton beams. While overlapped, the antiprotons would lose their velocity errors to the electron bean in a process called "electron cooling". While all the experts were sure the experiment would fail, we did not fail. Electron cooling technology is a critical component of ECOFusion, but electron cooling can also be used to cool muons.


Cooling Muons 2. A muon is a particle that in almost every way is the same as an electron, it is just heavier. But it also doesn't live very long, as it decays into an electron and two neutrinos in about 2 microseconds. (A microsecond is one millionth of a second.) Despite its short lifetime, scientists are very serious about forming beams of muons to collide with one another. That is because both electron collisions and proton collisions have fundamental problems at high energy. Muons don't have those problems. A muon collider would work if one could increase the beam density fast enough to make it worthwhile. So I looked into electron cooling of muons back in 2011.


Cooling Muons 3. It only took about a week once I put my mind to it in order to work out the parameters needed for electron cooling of muons. The analysis showed that what is needed is 3,800 electron beam systems, each supplying 1000 Amperes of beam current. But once built, such a system would increase the density of the muon beams to the point where muon beams could be formed to do high energy physics experimentation. And while the number and size of the systems may seem large, keep in mind that the superconducting super collider (SSC) was planned to be a ten billion dollar effort to build an accelerator that was to be about 55 miles in circumference. By high energy physics standards, electron cooling of muons was a very doable thing.


Cooling Muons 4. I submitted the paper on muon cooling to Physical Review Letters, known as the top journal for physics. Many years ago they had published my paper on electron cooling of positrons (the antimatter electron), so I was hopeful that they would publish this one as well. The new paper described how to make a muon collider a reality, which could be quite important for high energy physics research. It was immediately rejected as not being important enough, which was absurd, so I replied with a letter pointing out that this would enable the next generation of high energy physics experimentation. The paper was then sent out for review.


Cooling Muons 5 - Conclusion. After many weeks, the Physical Review informed me that my paper had been rejected. They had sent it to two reviewers (and maybe a third, I have forgotten) but only one replied to them. The reply they did get was a short paragraph asserting that my idea had many, many flaws but that he (or she) would only mention one - that it is well known that high current, low energy electron beams are unstable. Of course, this was the same "flaw" that had been mentioned on my fusion work, and while I have a patent showing how to overcome this, it is now a "known truth of nature". At that point I tried no more, as I felt I would be wasting my time. I was struck by the shear laziness of the editors and reviewers, and this canard of "there are many, many problems" followed by the listing of "only one" has gotten quite old. If there are many, list them. If not, just state the one fact that obviates the work in question. You only need one problem for a work to be rejected as incorrect; there is no need to vaguely accuse it of massive error only to be political about it. A reviewer's and editors jobs are to review and edit, respectively, and then they should request rebuttals and make an effort to understand the rebuttals in order for science to advance. It is not their job to simply make lazy, opaque, and summary judgments to preserve the status quo. No one seems to even do their basic jobs anymore.