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When I was undergraduate student I asked to my proffesor why nobody has made a synchrotron machine with a superconducting circular wire and magnetic field to accelerate electrons properly and to maintain the relativistic regime. In actual synchrotrons there are several sources that cause loses in bunch focusing, but with a very thin superconducting wire I think it is possible to make a tabletop synchrotron because it has no loses, ohmnic resistance is zero. What is the practial impediment to fabricate such a synchrotron?

JoeCoolman
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    Not sure what you mean by "tabletop", but small accelerators for industrial and medical purposes are available from multiple manufacturers. One could probably build a really small machines with permanent magnets... but you would still require an expensive vacuum system (that would take in the entire space below the table) and what would you do with those trivial particle energies? – CuriousOne Mar 05 '16 at 20:22
  • What does the word "properly" mean as used here? And does the penultimate sentence imply that you imagining accelerating the beam in a super-conducting wire? At this point I find this post to be very unclear. – dmckee --- ex-moderator kitten Mar 05 '16 at 21:11
  • Is your idea for the wire to form a circle? The mag field would circle the wire, falling off as the distance from the wire increases. There would be a spot in the plane of the circle and at greater radius than the circle, at a particular distance from the wire, where the mag field would bend the momentum p particle so that it follows the circle round. Unfortunately, this spot is unstable. If the particle went to slightly smaller radius, the field would get bigger, bending the particle in to hit the wire. If the particle went to a larger radius, it would bend more and more outward. – Gary Godfrey Mar 05 '16 at 21:11
  • It is worth mentioning that it is not just the magnetic fields that you need for a synchrotron. Typically you also want to accelerate your particles with high voltage (MeV, GeV, etc..). So either you use high voltage components, or high powered RF cavities. If you are fine with (relatively) low-energy beams, than you definitely can do it on the tabletop, superconducting magnets are not necessary, Iron works fine. – KF Gauss Jul 02 '19 at 05:04
  • I do not mean to use a superconducting ring to generate a magnetic field, but as a circuit through which a group of electrons can rotate at the speed of light and thus emit synchrotron radiation. One could make a hoop of 20cm in diameter, put it at 5 Kelvin and gradually accelerate the electrons with an external magnetic field (Faraday's induction) until reaching the relativistic regime and Voila!! you already have your portable synchrotron !! http://www.madsci.org/posts/archives/1999-09/936213072.Ph.r.html – JoeCoolman Jan 26 '20 at 20:00

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Back In The Day, Scientific American was an amazing magazine - The best place in the world for a high school student to learn about science. Two of the best things about it were the Mathematical Games and Amateur Scientist columns. They were incredible, in the literal sense of unbelievably good.

Amateur Scientist was at its best when C. L. Stong was editor, from 1952 - 1978. This is the Amateur Scientist column from September, 1953.

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I found the entire collection of C. L. Stong's articles online here. See Cyclotron in the table of contents.

OK, it doesn't use superconducting wire, but it is definitely a tabletop project. He even tells you how to build the vacuum pump. See this for difference between a cyclotron and a synchrotron.

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mmesser314
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  • Put a wire of radius R perpendicular to a constant uniform magnetic field B (MF) and the electron will turn around the wire describing a circle in accord with formula [(29.1) ] (http://www.feynmanlectures.caltech.edu/II_29.html), as the R radius is constant (the wire radius is fixed), you can control the speed v with B magnitude!. As the electrons in the wire don't collide with anything in the superconducting regime, it is like they move in a perfectly vacuum environment and with very strong magnetic field, you can move electrons at very very high velocity. – JoeCoolman Mar 07 '16 at 04:35
  • I agree with you, Scientific American was a great magazine in the past century. Returning to my issue, I think this is a nice experiment to see Quantum effects and Relativity Theory working together. I have no funds to perform this experiment and watch what happens :-( – JoeCoolman Mar 07 '16 at 16:29