Cool stuff! Here are a few interesting resources:<p><a href="http://www.techlib.com/science/ion.html" rel="nofollow">http://www.techlib.com/science/ion.html</a> - old and gold. A friend tried building these ion chambers, but apparently getting high enough isolation between the container and the electrode was very hard.<p><a href="http://physicsopenlab.org/2016/04/24/diy-cherenkov-detector/" rel="nofollow">http://physicsopenlab.org/2016/04/24/diy-cherenkov-detector/</a> - one for detecting muons (a PMT taped inside a thermos)<p>And a fun little application note from Maxim to build a gamma detector from a photodiode : <a href="https://www.maximintegrated.com/en/design/technical-documents/app-notes/2/2236.html" rel="nofollow">https://www.maximintegrated.com/en/design/technical-document...</a>
Speaking of CERN at home, the Fusor Forum [0] is a good place to visit. It's a community for fusor experimenters - a fusor is basically a glow discharge tube, but capable of achieving nuclear fusion. It's not an easy project, but has been extensively documented, and it's potentially doable by anyone with dedication.<p>A class of more difficult projects is particle accelerators. Many people built fusors, but fewer people had built electrostatic and linear accelerators. In addition to technical difficulties, X-ray hazards from an accelerator is much greater than a fusor.<p>Cyclotrons are the hardest, a successful build is extremely rare. Experimenters reported that there were still considerable difficulties even with access to a college lab. In 2010, there was a "Small Cyclotron Conference" [1] - a meetup event for experimenters to share experience. It featured many fascinating presentations, make sure to see [2][3][4].<p>[0] <a href="https://fusor.net/board/" rel="nofollow">https://fusor.net/board/</a><p>[1] <a href="https://web.archive.org/web/20110725214245/http://cyclotronconference.org/" rel="nofollow">https://web.archive.org/web/20110725214245/http://cyclotronc...</a><p>[2] <a href="https://web.archive.org/web/20110725214959/http://cyclotronconference.org/presentations/2010cycconf_YULY_houghton.pdf" rel="nofollow">https://web.archive.org/web/20110725214959/http://cyclotronc...</a><p>[3] <a href="https://web.archive.org/web/20110725214353/http://cyclotronconference.org/presentations/2010cycconf_cyckids.pdf" rel="nofollow">https://web.archive.org/web/20110725214353/http://cyclotronc...</a><p>[4] <a href="https://web.archive.org/web/20110725220048/http://cyclotronconference.org/presentations/cyclotron_apr_23_2010_houghton_3.pdf" rel="nofollow">https://web.archive.org/web/20110725220048/http://cyclotronc...</a>
Here is a much simpler detector: A bottle of Corona (or any other beer in a long-necked, clear bottle) makes a workable cloud chamber. Chill well in the freezer, and watch the neck closely as you open it. You may see the streak of a cosmic ray passing through just as the cloud of condensation forms. Of course, as a bonus, it may take more than one try…. It's not an ideal project to do with your teen-aged child—a soda doesn't get cold enough, it has to be a beer. And yes, it really does work.
Charles Stross had an interesting short story about hobbiest particle accelerators called "Dechlorinating the Moderator": <a href="http://www.antipope.org/charlie/fiction/moderator.html" rel="nofollow">http://www.antipope.org/charlie/fiction/moderator.html</a><p>I was hoping this article would cover building a particle accelerator in a pool, but it only covers the detection part of the system.
> The problem seems to be that sound cards (or chips) in modern PCs are too clever for their own good. They are designed to optimise microphone input for Skype and Zoom and that means removing the noise and extraneous clicks that are exactly the signal that the detector puts out.<p>Ugh! I wonder what other hidden features are lurking on my laptop hardware. I am conflicted because while I understand perfectly well why market forces compel hardware manufacturers to add these "features", I don't like the idea of not being able to trust my primary computing hardware.
Quick tip for pulling these types of signals out of noise: use a trapezoidal filter. It's just the difference between two offset moving averages. The length of the average (peak time) serves as an integration that removes high frequency noise. The offset (gap time) provides differentiation of the integrated signal, which removes low frequency changes in baseline. Timing precision is improved by using the trap filter output rather than the raw signal compared to a threshold, as it effectively acts like a constant fraction discriminator. It also makes it easier to deal with pile-up events where multiple waveforms lie on top of each other, though that's improbable unless you measure a source that's really hot or pulsed.