this post was submitted on 15 Jul 2024
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Radioactivity (mander.xyz)
submitted 5 months ago by [email protected] to c/[email protected]
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[–] [email protected] 33 points 5 months ago (3 children)

Marie Curie studied radioactivity with pure and very active materials with no protection. The radioactivity of the notebook is indirect radioactivity, that is material that becomes radioactive after being exposed to powerful ionizing radiations. It must be noted that the notebook may not be deadly radioactive. And if it will be for 1500 years, it won't be deadly for 1500 years. For reference, bananas tend to be radioactive too. And you are exposed to ionizing radiations when you take the plane.

Chernobyl had two reactors burn iirc. Most of the radioactive material was in the reactor, but the fire made smoke out of radioactive materials. The quantity of smoke, in kg, that go out was significant, but it got diluted in the atmosphere and spread. Which means there wasn't so much dust, in mass, that got in any one place. The dust is also not only uranium, but a combination of uranium and materials that were contaminated like the notebook. With the rain, the dust was washed and distributed more, and with the time, materials become less and less radioactive.

Both the book and chernobyl are not dangerously radioactive. But because of the nature of radioactivity, care must always be taken.

[–] [email protected] 3 points 5 months ago (1 children)

Ionizing radiation can't produce secondary radioactivity in materials...

[–] [email protected] -1 points 5 months ago (1 children)

Well, maybe explain my confusion then, instead of being an ass.

[–] [email protected] 6 points 5 months ago* (last edited 5 months ago) (2 children)

So there’s four types of radiation: alpha, beta, gamma, and neutron. When you’re talking about radioactive materials, it’s almost exclusively the first three. In addition to the inherent danger of the object itself, there’s also the danger of radioactive contamination: not making other things radioactive, but shedding bits of themselves as dust and then that dust getting on other things, or getting ingested/inhaled by humans.

Active fission reactions, like what goes on in the core of a nuclear reactor (or perhaps messing around with some plutonium and a screwdriver), produce neutron radiation. Neutrons can make other things radioactive, via a process called “neutron activation”, whereby the neutrons bind to the material and change some of the atoms into radioactive isotopes.

I hope that helps, and feel free to ask me anything else about radiation. I have some education about it thanks to my job, and I’m always happy to help other people understand it more as well.

[–] [email protected] 1 points 5 months ago (1 children)

Ha ! Turns out I'm right after all : radioactivation can happen with all type of radiations. But neutron activation is the lowest energy one.

You are right that it's probably a contamination for the book though, and not directly an activation (although carbon can be activated and will be found in the book).

[–] [email protected] 3 points 5 months ago* (last edited 5 months ago) (1 children)

The thing you said that someone disagreed with was calling it ionizing radiation, which is a more general term and describes radiation with enough energy to ionize an atom or molecule, which means stripping off at least one of its electrons. That requires a lot less energy than activating nuclei in an element that is not radioactive to radioactivity. UV light and X-rays are both ionising radiation, but are not from radioactivity and cannot induce radioactivity. Of course a lot of radioactive radiation (α, β, γ) is also too low-energy to activate more nuclei. It depends on the energy of the radiation and the specific element you're trying to activate (how close it is to being radioactive, so to speak).

So like CommissarVulpin said - the real danger is more likely to be contamination

[–] [email protected] 2 points 5 months ago* (last edited 5 months ago)

Yeah, like you can activate small amounts of material with alpha particles from a particle accelerator like Cockcroft did or really bombarding them with relatively low energy concentrated alpha particles like Curie's daughter did, but it's not generally a major contributing factor to the radioactivity from just being around alpha emitters since you really have to do it very intentionally.

[–] [email protected] 1 points 5 months ago

I know quite a bit about radioactivity thanks to my studies. I was sure all radiations could activate something, but it turns out I was wrong apparently because I can't find anything but neutron activation.

I'm pretty sure alpha, beta and gamma rays can stick to a particle, often bringing it in an unstable state that will force it to release something to get into a stable state. That's particle physics. And that's why we call them ionising radiations : because they turn atoms into ions. But my memories are definitely fuzzy, and it was not were I was the best.

Those radiations may only activate for a too short time to be useful maybe? I don't know.

[–] [email protected] 12 points 5 months ago (1 children)

They're contaminated, not neutron activated. The curies didn't get to the point of developing an unshielded nuclear reactor that would sufficiently neutron activate their stuff. They just liked to carry around radium and polonium which also have decay products that themselves are radioactive and they contaminated everything.

[–] [email protected] 2 points 5 months ago (1 children)

Thanks for the precision. Still, the result is the same I'm sure.

[–] [email protected] 10 points 5 months ago

More or less. The difference is that, if they really wanted to, they could very thoroughly clean the notebook and take most of the contamination off. I’m guessing they won’t because a) It’s a historical artifact and they don’t want to risk damaging it, b) the contamination is so low-level that it’s not dangerous as long as you don’t lick it or something, and/or c) there’s a bit of a shock factor in watching a scientist’s notebook make a Geiger counter freak out.