0zelot

The process is more involved than it seems at first, nasty toluene is required and only mentioned once in the methods section. The chemical treatment is a bit different, but I would expect similar results and difficulties as NileRed found when following the previous method from the same research group in 2016: https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201600...

Also the drastic change of 1 mm thick balsa wood from rigid to foillike around 00:27-28 in the "Movie S2" of the supplemental material is quite surprising: https://advances.sciencemag.org/content/suppl/2021/01/25/7.5...

this some one is part of that chips' engineering team :-)

The pulse detection works really quite satisfactory with the current method and for beta-decay electrons and alphas. I also prefer that the derivative is easy to understand for students since this is still mainly an educational project. For detecting lower energy particles like fluorescence x-rays, your proposal would be certainly something to investigate. However, for improving the SNR I would in general first redesign the amplifier. It's really optimized for super low part count and costs at the moment. That said, I will definitely keep you suggestion in mind. Thanks!

In principle that is a good idea and nice digital version of analog pulse shaping. However, the pulses have a very distinctive shape (not visible in the blog post picture, but here in figure 7/9: https://www.mdpi.com/1424-8220/19/19/4264). My programs use the trigger level just to select which waveform snippets are recorded. The peaks themselves are then identified by their steep slopes which shows up nicely in the derivatives: https://github.com/ozel/DIY_particle_detector/blob/90c180207...

The circuit used in the blog article is a very much simplified version of the Maxim one. And probably not so much worse in terms of signal to noise ratio: https://github.com/ozel/DIY_particle_detector/

The ion chambers are impressive because even lower-cost. But they also detect the presence of people, touches and what not. :) My favourite aspect of silicon sensors like those PIN diodes is that you get the absorbed particle energy as well. In particular with alpha particles that gets quite interesting when measuring for example old ceramics painted with uranium glaze ('Fiestaware').

or one of those even cheaper 16bit USB soundcards https://github.com/ozel/DIY_particle_detector/wiki/Soundcard... I believe Steve (who wrote the blog) might have had the wrong cable for his other computer (3-pin vs. 4-pin 3.5 mm jack)

just to be clear: I had not intended/endorsed any double posting. It just happened that someone submitted it as well.

someone else posted this as news, discussions ongoing over here https://news.ycombinator.com/item?id=23196177

thanks for pointing it out! When I had posted this initially, I had almost zero karma... ;)

yes totally. There is a great DIY project for doing that https://www.fourmilab.ch/hotbits/ It's not required to have the particle energy measured for making random numbers, detecting precisely the arrival time of particles is more important plus having a high hit rate is usually desired. My DIY detectors are not optimized in that way but it would work in principle. Timestamps are already recorded by the python scripts on github, it would be just a matter of evaluating them.

Yes, radon is pretty hilarious and spreads in very unexpected ways. Completely wrapping sources of radon like uranium or thorium minerals (or these bracelets containing some of that), only holds back the diffusion process for some time unless the shielding is really thick and very dense. That's why radon accumulates so well in household cellars, it penetrates concrete walls easily.

If you look closely in thought emporiums video (link below), the thick clouds - representing each the full paths of individual alpha particles (from the point of decay until full absorption in the air) - don't originate right at the surface of his shielding materials (paper, chicken skin... whatever). Instead, the alpha particle clouds stand by themselves in free space and can only really stem from radon that decided to decay at those positions somewhere outside of the shielding (transforming to "solid" polonium in that process and sticking itself to the next closest lump of molecules/dust). If the alpha particles would penetrate the shieldings (which they can't because of too much material/density), we would see clouds stemming directly from the shielding surfaces which I don't see happening:

https://www.youtube.com/watch?v=C7TwBUxxIC0&feature=youtu.be... You may find and like my comment there, maybe it helps to fight some misconceptions about natural radioactivity. ;-)

Let me just point here again to the project entries on Kitspace.org:

https://kitspace.org/boards/github.com/ozel/diy_particle_det...

https://kitspace.org/boards/github.com/ozel/diy_particle_det...

Yes, this project is very much doable for electronic beginners with a knack for science (16-year olds who have never soldered manage it well if guided a little bit). The parts are easy to solder and ordering the circuit board will make your life much easier in order to get it working. BTW, no one earns money with the kitspace website above. This is community-run and intended to make open hardware projects easier to build by simplifying the ordering procedures. The parts and board suppliers linked on kitspace should cover most of the world.

even the alpha-spectrometer might work if soldered wisely on a regular prototyping grid. in any case, thoroughly cleaning after soldering with alcohol will help. but considering the really cheap and fast PCB productions nowadays, the hassle is most likely not worth it.

here you go https://www.mdpi.com/1424-8220/19/19/4264

Isopropyl alcohol works well if it is of high purity (we use 96% I think). Methyl alcohol would be a really dangerous choice.

also its website: http://www.cosmicwatch.lns.mit.edu

In terms of difficulty to build and operate it, I would rate the discussed projects such: cloud chamber < DIY particle detector (electron-detector variant) < DIY particle detector (alpha-spectrometer variant) < desktop muon detector

Even DIY cloud chambers can be a bit tricky to get running for the first time (especially with too high humidity like in summer). Just don't give up! ;-) A few tips can be found in this manual: https://scoollab.web.cern.ch/cloud-chamber

Unfortunately, that video contained some flawed conclusions. I had left a comment back then. Alpha particles from natural sources like an uranium stone penetrate 50 micrometers of solid hard material at most. Let's give it maybe 100 micrometers of soft paper, but that's about it. What was most likely observed in that video is radon, which is a radioactive gas, slowly diffusing out of uranium or thorium stones. Since it's gaseous, it can circumvent the paper and then do its alpha decay just behind it. I wrote a few lines on those aspects in this article https://www.mdpi.com/1424-8220/19/19/4264

this is possible! you can use a thin foil made from e.g. mylar, for example taken from a cracked-open old large foil capacitor and superglue one layer on the rim of the diode's metal case. It can then point through a hole into the outside of the tin box if not held into direct sunlight (some additional foam ring can be used to help block more light). Using one of the sturdy aluminum die-cast cases I've listed in the schematic should be favored in a mobile scenario. Much less affected by vibrations/microphonic effect.

Hey, project owner here. Glad you all enjoy this! :-) I've never built my particle detectors on a breadboard. It is extremely likely that they will oscillate or frustrate in another way. You have to keep in mind that the amplification is enormously large, per particle only a few thousands of charges are being generated and turned into a still tiny voltage. The lower 10M-feedback electron-detector version works if _soldered_ on a prototyping/veroboard. Those with regular hole patterns - if the parts are put really close together.

Please don't be put off by the circuit board requirement, I have listed it on kitspace such that it is really easy and cheap to get one: https://kitspace.org/boards/github.com/ozel/diy_particle_det... Even if you have never ordered a PCB, it should be straight forward using kitspace as a proxy to get it right.

For beginners, I would propose soldering the electron-detector first (on the plus side, it has 4 times more the sensitivity) and if that works swap few parts and upgrade to the alpha-spectrometer variant since that is a bit more tricky to operate and get running. I've commented on the through-hole/SMD choice and similar questions in this twitter thread https://twitter.com/0zelot/status/1260931205676990466.

In short, I choose leaded components over SMD where possible such that it is easy to solder. But analog signal integrity and low noise vs. signal require a circuit board.