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  • Muons are fundamental particles in our universe that are essentially exactly the same as electrons,

  • but heavier - 206.77 times heavier, to be precise.

  • Muons are super fascinating for a number of famous reasons, including (and this is definitely

  • an incomplete list) as an experimental test of time dilation, as a catalyst making fusion

  • possible at room temperature, and that they can be used to make muonic versions of atoms,

  • like muonic hydrogen (with a proton and a muon, instead of a proton and electron).

  • But muons decay into an electron and some neutrinos after just a few microseconds on

  • average, so they're hard to store.

  • So to do experiments on muons, you need to have a source of muons on hand.

  • A small number of muons are produced naturally by cosmic rays striking our atmosphere, but

  • one of the best ways of consistently and reliably making a lot of muons is with a particle accelerator.

  • First, you take hydrogen and you strip off the electrons, leaving you with protons (protons,

  • as a reminder, are not fundamental particles - they consist of two up quarks and a down

  • quark, stuck together by mutual attraction due to the strong nuclear force).

  • Then you accelerate the protons really fast in an electric field (or a bunch of electric

  • fields) and crash them into some other atomic nuclei, like lithium or carbon or whatever.

  • The energy of the collision creates a whole mess of particles that goes flying out, but

  • most importantly for our purposes, it creates a particle called a pion - either a pion with

  • positive electric charge made from an up quark and an anti-down quark, or pion with negative

  • electric charge made of a down and anti-up quark.

  • If the pions keep traveling in a vacuum so that they don't bump into anything else,

  • they'll spontaneously decay after about 26 nanoseconds, most frequently turning into

  • a muon and a neutrino.

  • Which you can use for fusion, or testing special relativity, or making cool cloud chamber designs.

  • And that's how you make muons - accelerate protons with enough energy that when they

  • crash into other nuclei, the energy of the collision creates pions, which then decay

  • into muons.

  • Which, of course, after 2.2 microseconds on average, themselves spontaneously decay.

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Muons are fundamental particles in our universe that are essentially exactly the same as electrons,

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How To Make MUONS

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    Summer posted on 2021/03/02
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