That Gamma Ray Detector in my Pocket

Idaho National laboratories scientists (in Idaho Falls, ‘natch) have transformed ordinary cell phone cameras into gamma-ray detectors, with only the addition of black tape to keep out visible light.  The resulting calculations include the radiation dose and the eV rating (“the energy spectrum”) of the incident particle/ray.

The theory is, the CMOS detectors in your phone should be able to react to incident gamma rays because they have gigantic energies compared to photons in the visible spectrum 20,000eV, vs. like, 3 eV. No contest, right?  That is where the magic comes in.  When the incident ray strikes the CMOS detector, the extra 10,000 or so volts turns into a bunch of electrons running around the CMOS array, possibly leaving an interesting trail for clever software algorithms to interpret in terms of eV input and direction of incidence.  Of course the CMOS is flat and so the best information comes from gamma rays that strike close to the plane of the CMOS detector (too bad; the universe is full of gamma rays that we need to study if we are ever to figure out the cosmos…but I’ll get to that).

You can probably see where I’m going with this, right?  What if all cell phones had these detectors and phoned a central repository when they got a strike with information about the location of the phone, its orientation in space, the time of the incident and the eV of the strike?  Millions (soon to be billions) of people have these phones RIGHT NOW. This can make the Earth a 24,000 mile-wide gamma ray detector array with billions of detectors, RIGHT NOW.  With the kind of smart detection algorithms and big data-crunching hardware available, lots of physics mysteries will begin to clear themselves up.

Sadly, I can’t find if these guys (Joshua Cogliati and company at Idaho National labs1) have made their application available, though some of the code is already published.  I will keep you posted, however, if I find anything interesting.

So, my cell phone is now a gamma ray detector as well as a heart monitor and

general signaling device.  I can’t help but think I have seen this somewhere before.

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1.  Using CMOS Sensors in a Cellphone for Gamma Detection and Classification, Joshua J. Cogliati, Kurt W. Derr, Jayson Wharton  http://arxiv.org/abs/1401.0766