TE Coan Outreach & Global Pedagogy

Pedagogical Muon Lifetime Experiment

In response to the dearth of high-quality experiments for undergraduate physics majors, Professor Jingbo Ye and I have developed a novel pedagogical muon lifetime experiment specifically intended for undergraduate physics laboratory instruction. This experiment's instrument uses modern and inexpensive electronics to perform the essential timing of the muon's 2.2 μsec lifetime. The instrument is also capable of demonstrating the time dilation effect of special relativity, measuring the μ+/μ- sea level charge ratio, measuring the Fermi coupling constant GF, and providing a source of genuinely random numbers for testing standard probability distributions. Prototype versions of the instrument have been used in Quarknet teacher workshops. To ensure that the instrument is widely available to colleges and universities, we founded a company (MATPHYS LLC), that manufactures them. Currently, over 150 instruments are in use at universities throughout the world. A technical description of the experiment is published in the American Journal of Physics, vol. 74, p161 (2006).


  • Particle Detectors (ppt format, 6.9 MB)   General lecture describing accelerators and a few detectors used extensively in
    particle physics experiments. Many images were lifted from a variety of public www sites (CERN, CLEO, CPEP, FNAL, SLAC, SNO and others).
  • Particle Detectors, pt. 1, (5.8 MB, pdf format)   PDF version of the first 23 slides.
  • Particle Detectors, pt. 2, (3.6 MB, pdf format)  PDF version of the last 5 slides.
    We (seven high school teachers and myself) are constructing 3 pairs of scintillator trigger paddles to be used to estimate the mean production height of cosmic ray induced muons in the atmosphere. The general idea is to measure the sea-level muon flux for a paddle pair as a function of zenith angle out to about 45 degrees, and to then relate the reduction in flux to the increased pathlength of muons in the atmosphere. The teachers polish and wrap the scintillator, glue the photomultiplier tube (pmt) to the scintillator, "stuff" the printed circuit board used for the pmt readout, assemble the detector, and make the coincidence measurements. The pmt readout scheme borrows heavily from the work of Howard Matis and his team.

    Muon trigger paddle construction

    Here you can see the group, soldering the pmt readout boards, a scintillator and pmt before gluing, and some of the wrapping techniques we used.

    <email to coan@mail.physics.smu.edu>

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