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Why is my dryer radioactive?

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Re: Why is my dryer radioactive?

#151

Post by fastneutron »

dotBen wrote: post #4

Related: HNer recommendations for home geiger counters? (serious request - for general fun/experimentation/curiosity satiation)

At the high end, the standard workhorse for really serious hobbyists and rock hunters is the Ludlum Model 3 with a 44-9 pancake probe [1,2]. Throw in a scintillation probe [3] if you really want to find needles in haystacks. There are perennial bidding wars on ebay for these things surplus, but the manufacturer has a very hobbyist-friendly reputation. They've walked me through a few DIY repair jobs on ancient equipment they were under no obligation to support.

1. https://ludlums.com/products/all-products/product/model-3

2. https://ludlums.com/products/all-products/product/model-44-9

3. https://ludlums.com/products/all-products/product/model-44-1...

Re: Why is my dryer radioactive?

#152

Post by EntropicHeaven »

_Algernon_ wrote: post #150
jve wrote: post #143

Earlier quoted context omitted.

What's the difference between alpha/beta/gamma and which is of concern?

Alpha has the shortest range and can be blocked by a piece of paper. Alpha radiation consists of protons. Gamma goes through most things and has the highest range. Gamma consists of electro magnetic radiation. Beta is somewhere in the middle. It consists of electrons. All are of concern, but Alfa is mainly of concern if ingested or inhaled. This is because all the radiation will be absorbed by your body, while most g…

> Alpha radiation consists of protons.

Alpha radiation is helium-4 nucleus - two protons and two neutrons.

> Beta is somewhere in the middle. It consists of electrons.

Beta is either electron (β− decay) or positron (β+ decay)

Re: Why is my dryer radioactive?

#153

Post by eternauta3k »

red75prime wrote: post #145
bcbrown wrote: post #137

Earlier quoted context omitted.

> For another example, see speed of light in glass is slower than vacuum. I'd love for you to explain what you mean by this. Either you're mistaken or I'm about to learn something really interesting. Here's a link a quick search brought me, for reference. Are you talking about something other than refractive index, ratios of c, and prisms? Like a latency metric of some kind? I'm very curious. https://en.wikipedia.org…

It's probably that photons always propagate at c and that the apparent change of speed of light in glass is caused by photon absorption and delayed reemission by atoms (at least it's how perturbation theory of quantum electrodynamics describes the process).

Do you really need photons and quantum stuff though? "Just" learn about how dielectric materials work + how EM waves work from Griffiths and then everything will make sense.

Re: Why is my dryer radioactive?

#154

Post by brippalcharrid »

jojobas wrote: post #144
antognini wrote: post #134

Earlier quoted context omitted.

Yes, this is why the idea to use Po-210 was a stroke of (evil) genius. Because of its unique decay profile it is extremely hard to detect. The FSB agents who did this could obtain a small but lethal dose of Po-210 in Russia and then carry it across borders dissolved in a vial of water. In that state it is not dangerous, so the agents had little risk to themselves by carrying it. And it is also undetectable by border…

When alpha particles are stopped by anything, secondary x-rays are created. I wonder if airport x-ray machines are sensitive enough to pick that up.

It would probably just appear as faint noise, and then only if it happened to be at wavelengths that the sensors were tuned to detect, and which the machine's signal processors weren't trying to ignore, and if the image processing was designed to draw attention to it.

Re: Why is my dryer radioactive?

#155

Post by red75prime »

eternauta3k wrote: post #153
red75prime wrote: post #145

Earlier quoted context omitted.

It's probably that photons always propagate at c and that the apparent change of speed of light in glass is caused by photon absorption and delayed reemission by atoms (at least it's how perturbation theory of quantum electrodynamics describes the process).

Do you really need photons and quantum stuff though? "Just" learn about how dielectric materials work + how EM waves work from Griffiths and then everything will make sense.

Depends on what you want. A useful approximation, or the latest approximation that is closer to how it really is.

Re: Why is my dryer radioactive?

#156

Post by simmo9000 »

antognini wrote: post #66
BetterGeiger wrote: post #33

I think the core of the explanation given is correct but some of the adjacent details need adjustment. The important part is: "Clothes dryers are very effective at making statically charged surfaces. (Dryer sheets help.) So when radon and its temporary decay products are blown through the dryer, electrically-polarized molecules tend to be attracted to the charged surfaces" What that commenter misses is that nearly al…

> hobbyist grade detectors (Geiger tubes) are not sensitive to alpha but they are highly sensitive to beta and a little sensitivity to gamma. This was part of the reason why it took so long to discover the cause of Alexander Litvinenko's death by Polonium-210 poisoning. Doctors (and later detectives) had suspected some form of radiation poisoning, but the early tests used Geiger counters and came back negative. But P…

Reading more on Po-210, apparently it is used in anti-static objects.

"An antistatic fan made by NRD, of Grand Island, N.Y., contains 31,500 microcuries of polonium 210 — or, in theory, more than 10 lethal doses."

Source: https://www.nytimes.com/2006/12/03/weekinreview/03broad.html

Re: Why is my dryer radioactive?

#157

Post by [deleted] »

BetterGeiger wrote: post #44
kloch wrote: post #41

Earlier quoted context omitted.

> but they are highly sensitive to beta I’m not familiar with Geiger counter design/specs but would the considerable static electricity send some electrons into the detector and cause a false positive beta hit?

Beta particles are basically energetic electrons flying around, yes, but for a Geiger counter to detect them they have to be quite energetic in order to penetrate the Geiger tube itself (detection occurs essentially inside the tube, in the gas)... So I doubt that static field is generating electrons anywhere near that energy needed to be detected by a Geiger tube.

[deleted]

Re: Why is my dryer radioactive?

#158

Post by kloch »

BetterGeiger wrote: post #44
kloch wrote: post #41

Earlier quoted context omitted.

> but they are highly sensitive to beta I’m not familiar with Geiger counter design/specs but would the considerable static electricity send some electrons into the detector and cause a false positive beta hit?

Beta particles are basically energetic electrons flying around, yes, but for a Geiger counter to detect them they have to be quite energetic in order to penetrate the Geiger tube itself (detection occurs essentially inside the tube, in the gas)... So I doubt that static field is generating electrons anywhere near that energy needed to be detected by a Geiger tube.

Dryer static charges are probably a few keV at most so yeah that shouldn't make it through a metal envelope.

However, I wonder how well shielded the electronics are. In a poor quality design even the static charge fields themselves might trigger a false hit.

Re: Why is my dryer radioactive?

#159

Post by Radim »

inglor_cz wrote: post #27
r3trohack3r wrote: post #2

We had this issue in the Midwest (central Illinois). Can’t remember exactly why, but radon would accumulate in the basements. Had to have sensors and ventilation for it.

Some places in Czechia have a huge problem with radon emanating from the ancient bedrock below. These places, even though rural and not polluted, tend to have more deaths from lung cancer than the rust belt in northern Moravia, where air quality in general is worse, but the radon problem is almost non-existent. Newly built houses are required to be radon-proofed, AFAIK.

I remember that "radon killer" story being vastly overblown / debunked. Apparently anything up to 150Bq/m3 is fine or even beneficial for your health. [0]

Has the debunking itself been debunked? It's hard to keep track.

[0] https://www.osel.cz/3436-radon-neskodi-a-mozna-i-prospiva.ht...

Re: Why is my dryer radioactive?

#160

Post by hermitdev »

nocoiner wrote: post #124
BetterGeiger wrote: post #33

I think the core of the explanation given is correct but some of the adjacent details need adjustment. The important part is: "Clothes dryers are very effective at making statically charged surfaces. (Dryer sheets help.) So when radon and its temporary decay products are blown through the dryer, electrically-polarized molecules tend to be attracted to the charged surfaces" What that commenter misses is that nearly al…

Man, so glad I decided to finally click on the comments after seeing the article at the top of hn most the day - we don’t have radon where I live (I don’t think?) so I figured the dryer thing wasn’t applicable to me. But for the vast majority of my life, I’ve always wanted a Geiger counter, and once they were cheap and readily available on Amazon, I was just about to pull the trigger. And then Fukushima happened a we…

What's NPP here?
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