
The $100 muon detector - jonbaer
http://www.symmetrymagazine.org/article/the-100-muon-detector
======
stephengillie
Imagine outfitting a datacenter with these, and using them to understand the
rate of bit flips in your processors. Maybe we'll find some parts of the Earth
have fewer cosmic rays hitting there, and are thus are more naturally suited
to being datacenters.

~~~
keithpeter
The basements of large buildings made from concrete spring to mind, then
geographical areas that are at or below sea level.

Random thought: anti-coincidence detector? A detector above the RAM chips and
one below with data processing set so that if the detector above gets a count
and the one below does not or sees a count with significantly lower energy,
you _know_ some energy has been absorbed somewhere near the RAM.

~~~
InclinedPlane
> _The basements of large buildings made from concrete spring to mind_

What is concrete made out of? Rocks? What do rocks contain? Radioactive
elements.

So that's not actually the best way to protect against radiation.

~~~
frumiousirc
The energy involved in radioactive decay is far less than that of cosmic rays.
If the goal is to protect ICs from bit flips then indeed putting them under
concrete or natural rock will reduce them.

~~~
gnufx
You don't have a background in nuclear spectroscopy, and I claim my £5.

The irony of this: what is typically used for nuclear spectroscopy?
Semiconductor detectors? If you get one out -- albeit probably a
geranium^Wgermanium detector rather than silicon, if you do gamma rays --
potassium-40 products stand out in a typical environment. (I've mostly done
that over sandstone -- why the lab was there; it may be different somewhere
like Edinburgh.) Concentrated in a calibration source rather than a concrete
block, it would be controlled.

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brudgers
The paper:
[https://arxiv.org/abs/1606.01196](https://arxiv.org/abs/1606.01196)

~~~
godber
The paper contains the following link to the supplementary material which
contains BOM, PCB drawings and some code:

[https://dspace.mit.edu/handle/1721.1/102942](https://dspace.mit.edu/handle/1721.1/102942)

Edit: spelling and a little more info.

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tim333
Given muons can catalyse the nuclear fusion of deuterium and tritium I wonder
if you could extend this to your own very low power fusion reactor? Not quite
sure where you get the deuterium and tritium.

[https://en.wikipedia.org/wiki/Muon-
catalyzed_fusion](https://en.wikipedia.org/wiki/Muon-catalyzed_fusion)

~~~
gravypod
Tritium from firearms optics or iron sight paint and you'd need to make the
deuterium. Both quite expensive and still very doable.

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ChuckMcM
Interesting, I was just looking at the SiPM (its $132 qty 1
([http://sensl.com/estore/microfc-60035-smt/)](http://sensl.com/estore/microfc-60035-smt/\))),
nice to see it in use.

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1_listerine_pls
Any practical use?

~~~
CamperBob2
It's a great educational project for a physics class, from what I can tell.
The article
([http://arxiv.org/abs/1606.01196](http://arxiv.org/abs/1606.01196)) is nicely
detailed and accessible to undergraduates. Good introduction to instrument
design and construction, especially if (as the author suggests) the students
are asked to write their own analysis software for it.

As far as applications go, the article offers a few ideas:

 _1\. Measure the relative depths of subway stations across the city, using
the measured muon rates.

2\. Test relativistic time dilation on the cosmic ray flux by measuring the
flux at various elevations, such as in an airplane or on a mountain, compared
to sea level.

3\. Investigate correlations between the atmospheric
temperature/pressure/humidity and the count rate.

4\. Investigate seasonal variations in muon rates.

5\. Using multiple detectors, measure the angular muon rate by looking at the
coincidence rate.

6\. Lower the gain of the circuit to look at high-energy stopping muon events.
Investigate whether or not one can see the Michel electron from the muon
decay._

Tempted to build one, but I don't immediately understand how it discriminates
between muons and other forms of ionizing radiation that an ordinary Geiger
counter will pick up.

~~~
kaybe
Scintillators are able to resolve particle energy, and can be used to measure
a spectrum. Muons have very high energy, which can be used to identify them.

For extra certainty, you can use two stacked scintillators and only count a
signal if it occurs in both of them within nanoseconds. This also allows
determining the rough direction the particle came from since a particle that
comes in at a low angle will not hit both detectors. Changing the distance
between the scintillators will change the solid angle the instrument can
'see'. (as given by 5 in your list)

This guide for a student experiment has more background than the paper you
linked:

[http://home.fnal.gov/~group/WORK/muonDetection.pdf](http://home.fnal.gov/~group/WORK/muonDetection.pdf)

~~~
pif
> Scintillators are able to resolve particle energy

No, scintillators only detect a particle going through.

~~~
nullc
My (NaI based) gamma spectrometer disagrees.

~~~
nagrom
I suspect that this is a question of energy. At high energies, it's
difficult/impossible to stop a particle, so you place a row of scintillators
out, bend the charged particle path using a magnetic field and measure its
displacement (and thus velocity and thus energy).

At lower energies, you can stop the particle in, e.g. an NaI detector which is
known as calorimetry. Typically, of course, cosmic rays are quite high energy
and given the low rate of muon interaction calorimetry is
difficult/impossible. A HEP physicist may use both techniques, e.g. by using
heavy-metal plates to cause an EM cascade and measure the resultant shower in
a crystalline detector. But typically when one talks of scintillator devices
(and almost certainly in the case of cosmic rays) one talks of tracking and
measuring deflection in magnetic fields if wanting to measure the energy.

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JoeAltmaier
Put it into a usb stick, or a keychain, and we could all be collecting data.
The internet of things

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ape4
The next sensor for phones?

