Scintillocartography

Scintillocartography(ivan.sanchezortega.es)

49 points by jdelacueva 2 years ago | 21 comments

One line in the piece says "Observing the direct effects of radiation, although possible, requires extraordinary circumstances.". While this is mostly true, you can actually observe radiation directly, with your own eyeballs, without any extraordinary methods. Basically all you need is a radioactive source, scintillator and a very dark room. That's how scintillation counting was done back in the day. This sort of device is called a Spinthariscope, you can find examples of them on youtube and what you see is a lot like the map in the OP. So I'd say the author did a good job.

4gotunameagain 2 years ago | |

The author probably counts these as indirect effects, as it is the collision of the α particles with zinc sulfide, and not a direct effect of radiation like Cherenkov.

RugnirViking 2 years ago | | |

isnt cherenkov also caused by interaction with water molecules?

edit: the article goes into a little more detail and talks about how its due to the different speeds of light in water and vaccuum, and I don't know enough about semantics or physics to say what this means about my original question :)

defrost 2 years ago |

Interesting read, it culminates in making a sparkly twinkly map to graphically convey radon location and strength which seems a bit 1980s to my mind.

    For the work in Nuclear Sessions I’ve used a 2017 dataset of radon potential, published by the Spanish Nuclear Safety Council. 

    This dataset was selected purely on the basis of availability: it was the easiest (and first) geographic dataset regarding radiation to be found.

They could have gone for the full Australian 256 channel raw (or post processed full spectrum or "artifical colour" U-K-Th 3-channel) dataset covering the bulk of the continent.

https://www.ga.gov.au/scientific-topics/disciplines/geophysi...

The usual practice is to accumulate one second sample windows of the gamma spectrum while travelling at 70 m/s, normalise the data to remove various wobble factors, and extract three significant channels to form an RGB image - you can always add fiddle layers to indicate radon or out of band features (such as uncommon trace elements from atomic tests).

That said when reading the title I though this might be about the new trend in radiometric sampling - using a scintallation source surround by layered spinning masks - when you get a gamma spark you can better guess to some degree the direction of the source, when many gamma interactions accumulate you can build up a pretty decent 3-D image of gamma sources surrounding your instrument.

One of these was recently trialed in the HN infamous Western Australia Mining Company loses Radiactive Source! stories from earlier this year.

progbits 2 years ago |

I suppose this is as good place as any to ask: What is a good scintillating detector for DIY use? Geiger tubes are relatively easy to find, but all scintillators I could find were "ask for pricing" scientific equipment or some dubious old russian military stock (which I don't want even if it works).

speps 2 years ago |

The actual map animated map: https://ivan.sanchezortega.es/2023-02-radonmap/radonmap.html

nayuki 2 years ago |

> One of those circumstances is being close to a nuclear reactor submerged in water, which allows Cherenkov radiation to be observed. In layman’s terms: gamma radiation exits the reactor at the speed of light in a vaccuum, but the speed of light in water is lower, and photons have to slow down somehow. The direct, observable effect is that water glows blue.

Almost but not quite. The speed of light is always the speed of light. There's nothing wrong with gamma rays.

It's charged particles such as beta and alpha rays that generate the blue Cherenkov radiation. The writer's link to Wikipedia already reflects that.

NextHendrix 2 years ago | |

The speed of light in a vacuum is always the same, but not through dielectric media such as water or glass. In diamond it is less than half the speed.

nayuki 2 years ago | | |

You're right, but I knew that. I should've worded my statement in such a way to prevent criticism.

Gamma rays always follow the speed of light in the medium that they travel through, because they are light. They cannot exceed the local speed of light, thus they cannot generate Cherenkov radiation. It must be particles with charge and non-zero mass that are capable of generating Cherenkov radiation.

flobosg 2 years ago |

> Cloud chambers seem to be a thing of the past

I saw one at the German Museum of Technology (Deutsches Technikmuseum) in Berlin: https://technikmuseum.berlin/en/spectrum/world-of-experiment...

philbo 2 years ago |

> This blue glow has barely entered popular culture. The only two examples I’m aware of are the cinematographic depictions of the Chernobyl disaster, and the ficticious Nuka-Cola Quantum non-alcoholic beverage in the Fallout videogame series.

Don't forget Dr Manhattan from Watchmen!

ElectricalUnion 2 years ago | |

At least in Brazil, because of this pretty infamous accident, people now know to be aware of blue light sources.

* https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident

For the work in Nuclear Sessions I’ve used a 2017 dataset of radon potential, published by the Spanish Nuclear Safety Council. This dataset was selected purely on the basis of availability: it was the easiest (and first) geographic dataset regarding radiation to be found.