A sea of sparks: Seeing radioactivity

(maurycyz.com)

67 points | by maurycyz 20 hours ago

6 comments

  • DoctorOetker 14 hours ago
    I was hoping this would be an artists project page describing the passive imaging of radiation (i.e. not a simple X-ray scan).

    Imagine a planar array where each pixel gathers counts like an MCA (multichannel analyzer), mounted in some lead pinhole camera obscura.

    This would give an extremely wide range of channels didactically illustrating the presence of calcium in gypsum (dryboard etc), visually show backscatter, etc.

    Such pictures of modern and old city scenes would be mesmerizing to watch, partially seeing into buildings, the ground, ...

    • defrost 11 hours ago
      Takes a while to do an entire continent this way, luckily when you start in the 1970s it's all over by now.

      * https://www.ga.gov.au/bigobj/GA13928.pdf

      * https://www.ga.gov.au/bigobj/GA18007.pdf

      Visualising full 256 channel multispectral data can be tricky, the approach taken above was to take the raw data and process it to create a false colour RGB image representing the strength and interaction between natural background potassium, thorium, and uranium.

      • DoctorOetker 10 hours ago
        Thank you for this reference! I had been looking for such data for a long time.
        • defrost 9 hours ago
          It's been kicking about in geoscience collections, mining company archives, etc. for a while.

          Russians, South Africans, USAians, et al all run crews - we (Australia) have done Australia, Mali, other African regions, all of Fiji (many islands), India in May 1998 (the Pokhran-II nuclear test sites as they happened), and elsewhere.

          The data is one thing, processing raw spectrometer data is a whole other thing - calibrations, corrections, dead time, etc.

          See: Grasty / Minty GUIDE TO THE TECHNICAL SPECIFICATIONS FOR AIRBORNE GAMMA−RAY SURVEYS https://www.ga.gov.au/bigobj/GA7667.pdf

          • DoctorOetker 8 hours ago
            Do you know of similar maps for Europe?
            • defrost 5 hours ago
              This is a different kind of radiometric data that is available:

                The EUropean Radiological Data Exchange Platform (EURDEP) consists of data exchange mechanism and presentation website for radiological monitoring data which is collected and shared by 39 participating countries in almost REAL TIME.
              
              * https://remon.jrc.ec.europa.eu/About/Rad-Data-Exchange

              Certainly useful for a mapping European normal background, the details under the hood could be a pain (types and formats of data, etc), it's historic and ongoing chronological data for distributed fixed points.

              Their interactive public play map is normalised(?) raw total counts, _not_ a spectrum of gamma events bucketed by energy - ideally they are also recording and sharing full spectrum data at some stations in their network .. and making that publically available.

              Of possile interest:

              * https://www.abc.net.au/news/2022-08-10/hedley-marston-marali...

              * https://www.wakefieldpress.com.au/product/fallout/

            • defrost 8 hours ago
              Know of .. yes.

              Off hand, I'm not familiar with any public facing portals for downloading raw data.

              Bear in mind, these are "snapshot" static, historic, broad area spectrum maps - they're not live, they won't show new leaks, changes, etc.

              They are, however, "training data" for forming a kernel of a NASVD - Noise Adjusted Singular Value Decomposition - a bundle of all the major features of typical regular environmental radiation for some locale.

              If you fly about or have an instrument taking live readings and subtracting a normalised background kernel .. you get the faint trace "weird arse stuff" lighting up instead of being buried.

              Finland's the home of the NASVD author, the country used to run "find a barrel of waste" in a forrest compitions back in the day, they're adjacent to some radiometrically filthy submarine docks and pens just over a border.

              The game goes thus - fly at about 70m/sec about 80m above the deck in some kind of frame carrying 30 to 40 litres of doped crystal packs .. and pick out a signature in near real time from one second spectrum windows.

              They have data, I don't know about portals.

              https://www.helsinkitimes.fi/finland/finland-news/domestic/2...

              Can confirm, though, Cresco STOL's make a good platform: https://www.youtube.com/watch?v=1_MO5Wfomks

    • jareklupinski 13 hours ago
      currently trying to make a flip-dot display (think https://theartistbreakfast.com/works/spectral-flashbacks-ser...) but with some kind of radiation detector behind each pixel that will flip the dot when something passes through

      i made a small 3x3 proof of concept using more expensive geiger tubes, and their really long 'z-axis' lengths made 'traces' happen very often, like a persistent cloud chamber

      trying to find a reliable semiconductor (read:cheaper) method i can scale to an arbitrary number of pixels, but something seems to happen in between the bench and the wall :(

      • DoctorOetker 10 hours ago
        How many pixels would you aim for?

        I have considered

        * scanning a linear array of BPW34 photodiodes, in a similar spirit to a scanner to cover a plane, each photodiode going to its own "MCA circuit" (TIA->cheap audio codec like those from Everest Semi). Either direct measurement of generated charge pulses or covering the photodiode with phosphor on aluminum foil or so

        * cloud or bubble chamber (cloud chamber is less dense and will generate fewer events, so probably bubble chamber): instead of needing a large 2D or 1D array of parallel circuits, we image and track generated charged particles and use the trajectory starting end (less curved) to determine the source direction!

        * consider X-ray crystallography, an incoming straight beam can diffract in many directions on a monocrystal. rotating say a silicon wafer, and measuring the incoming photon energies with one or more photodiode/MCA circuits we can assign a source likelihood distribution by keeping track of the orientation of the monocrystal. akin to sparse sampling but instead of masks its diffraction patterns.

        If you have better ideas or variations in mind, let me know!

  • r2_pilot 18 hours ago
    If you haven't experienced a spinthariscope, I can highly recommend it. I bought one as a Christmas present for a buddy and we both enjoy its demonstration of radioactivity.
    • jcims 16 hours ago
      UnitedNuclear has these and a bunch of other interesting tidbits if anyone wants to give it a try. I bought a small bottle of heavy water as well, which I of course sampled and can confirm it has a slightly sweet taste to it.

      You really have to get your eyes adjusted to the dark to see anything with the spinthariscope. It ends up looking mostly like static on a green crt, but if your only reference frame is a cloud chamber, the volume of particles that are emitted from such a weak source is pretty remarkable.

  • cbm-vic-20 18 hours ago
    Don't miss a chance to see the Cherenkov radiation effect at your local research reactor.

    https://en.wikipedia.org/wiki/Cherenkov_radiation

  • lukasschwab 19 hours ago
    You won't make one at home, but cloud chambers[^1] reveal individual alpha particle tracks.

    There's one in the Musée des Arts et Métiers in Paris — blew my mind!

    [^1]: https://en.wikipedia.org/wiki/Cloud_chamber

    Edit: turns out people make these at home all the time. Sick!

    • Yenrabbit 19 hours ago
      You can easily make them at home (source, I did last weekend!).

      - Dry ice (mine came from something shipped cold)

      - Dark piece of metal (I used a 3D printer hot bed) on top of dry ice to get cold

      - IPA vapour (I poured some on a shop towel)

      - Some transparent container to house it all - I found a glass display cube on the side of the road, fish tanks or Tupperware also work.

      - Torch or something to provide side lighting

      Very cool to see evidence of the particles zooming around us, can highly recommend.

    • lukan 19 hours ago
      Well, google for "DIY cloud chamber" did result in quite some entries. Apart from youtube channels, with the first entry a guide from CERN:

      https://home.cern/news/news/experiments/how-make-your-own-cl...

    • alnwlsn 19 hours ago
      This can be done at home with a little effort. Less effort if you can get dry ice easily.

      https://hackaday.com/2019/01/13/see-the-radioactive-world-wi...

  • anfractuosity 17 hours ago
    https://dberard.com/home-built-stm/ shows individual atoms.
  • dvh 19 hours ago
    I tried the same with bananas. Got nothing.
    • thadt 19 hours ago
      Bananas are like XML that way. If you're not getting the results you want, you're just not using enough of them.
    • kergonath 19 hours ago
      Potassium-40 is not an alpha emitter.
      • fecal_henge 19 hours ago
        Maybe he used banana as the scintillator.
      • DetroitThrow 19 hours ago
        That's unrelated. He's been diligently substituting bananas in many experiments to mostly disappointment.
        • marginalia_nu 18 hours ago
          The banhattan project has been a fiasco.

          Chicago Peel 1 accomplished fission of fruit flies, which we felt was promising.

          The subsequent banana nuclear bomb tests have been an unmitigated disaster. There are so many damn bananas in and around the bikini atolls, just nothing. Not even a fizzle. Mojave is littered with peels. Oppenheimer slipped and broke his leg.

          Rumors are the Soviets are using avocados. Maybe that is the key. We are now constructing a demon core from an avocado split lengthwise.

          • thenthenthen 5 hours ago
            Haha brilliant thank you for your comment!
          • selimthegrim 17 hours ago
            This puts Raffi in a whole new light. Also maybe the Banana ball team are refugee all-stars.
        • onraglanroad 18 hours ago
          ...but occasional delight.