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The Case For a Muon Collider Succeeding the LHC Just Got Stronger

Posted by timothy on from the other-people's-money dept.

StartsWithABang writes: If you strike the upper atmosphere with a cosmic ray, you produce a whole host of particles, including muons. Despite having a mean lifetime of just 2.2 microseconds, and the speed of light being 300,000 km/s, those muons can reach the ground! That's a distance of 100 kilometers traveled, despite a non-relativistic estimate of just 660 meters. If we apply that same principle to particle accelerators, we discover an amazing possibility: the ability to create a collider with the cleanliness and precision of electron-positron colliders but the high energies of proton colliders. All we need to do is build a muon collider. A pipe dream and the stuff of science fiction just 20 years ago, recent advances have this on the brink of becoming reality, with a legitimate possibility that a muon-antimuon collider will be the LHC's successor.

3 of 53 comments (clear)

  1. Estimate of 660 meters by Translation+Error · · Score: 3, Informative
    In case anyone else was completely confused about the ''estimate of just 660 meters" in the summary:

    But let's do the math: even if these particles are moving at almost the speed of light--300,000 km/s--and they live for 2.2 microseconds, they should only be able to travel about 660 meters before decaying away.

    Yet I told you these particles are created at the top of the atmosphere, which is some 100 kilometers, or 100,000 meters up! From our perspective, that muon should never make it to the ground. And yet, it's Einstein to the rescue, thank to the fact that when objects move close to the speed of light, their clocks run slow.

    --
    When someone says, "Any fool can see ..." they're usually exactly right.
  2. Old news by Anonymous Coward · · Score: 5, Informative

    IAAAP (I am an accelerator physicist), and this is pretty old news. The US muon collider program is actually on its way out. Last year's Particle Physics Project Prioritization Panel (P5) advised the DOE to defund the muon collider project, redirecting funds toward the International Linear Collider (ILC)-- a 250GeV e+/e- precision Higgs factory-- and other projects:

    http://science.energy.gov/~/media/hep/hepap/pdf/May%202014/FINAL_P5_Report_Interactive_060214.pdf

    The DOE has followed P5's review, and Fermilab's muon collider project is winding down.

    1. Re:Old news by Anonymous Coward · · Score: 5, Informative

      IAAAP (I am an accelerator physicist), and this is pretty old news. The US muon collider program is actually on its way out. Last year's Particle Physics Project Prioritization Panel (P5) advised the DOE to defund the muon collider project, redirecting funds toward the International Linear Collider (ILC)-- a 250GeV e+/e- precision Higgs factory-- and other projects:

      According to this article it's easier to put energy in particles with substantial mass. They don't seem to leak as much.
      So how are they gonna accomplish these 2-3 x higher energies in the ILC over the LEP ? More massive electric fields ?

      It's all in the name. ILC = "International Linear Collider", i.e., two linacs pointed at each other. Synchrotron radiation only bites you if you're accelerating tangentially to the direction of motion. There's very little synchrotron radiation in a linear accelerator. LEP was a circular collider (proceeding the LHC, and occupying the same tunnel the LHC now uses), hence the synchrotron radiation problem.

      The trouble with linacs is they're somewhat wasteful. Each bunch only gets one crossing with the opposing beam, so you're constantly accelerating new bunches. At LEP you got something around 100 million chances for a bunch to interact with the opposing beam (assuming ~1hr fills)-- and that's assuming only one collision point.

      So, it's six to one, half-dozen to the other. Either you expend all your energy accelerating new bunches constantly, or you expend all your energy replacing what's lost to synchrotron radiation.

      --IAAAP