General > General Technical Chat
something is leaking in europe
<< < (3/9) > >>
Nusa:

--- Quote from: David Hess on June 29, 2020, 05:11:50 pm ---
--- Quote from: jogri on June 29, 2020, 09:53:27 am ----would also explain the Russian statement that both power plants are working normally
--- End quote ---

The Russians reported that nothing had happened at the Chernobyl power plant after they knew about the accident which also explains their current statements.  Why would you trust anything they say about such incidents?


--- Quote from: Porenbeton on June 29, 2020, 12:18:08 pm ---Also this isnt the 80s anymore with communist russia. I think if something in this scale happened, that it wouldnt take even 5 minutes until the social medias are full of it with videos/pictures etc.
--- End quote ---

Russia is still Russia.  If they had a nuclear accident, they will by default initially deny it.

--- End quote ---

Chernobyl is in Ukraine near the Belarus border. Not in Russia at all. All of those, and quite a few others, were part of the USSR, which broke up about 5 years after the accident.
jogri:

--- Quote from: edy on June 29, 2020, 06:27:16 pm ---I have always wanted to buy a Geiger counter or radiometer or other instrument that measures such incidents. I was also thinking to build from schematics and simply buy a Geiger–Müller tube. However, I'm at a loss as to what kind of instrument will do the job. Obviously they cover different types of radiation, calibrated to handle different level ranges, and so on. So what does someone buy? On a budget... Here are examples, many of which are under $100, some under $50. Anyone have experience with something reliable and does the job and good value:

And short of a nuclear catastrophe can we use any of these for fun educational experiments like measuring basement radon leaks, smoke detector radiation source, marble countertops, various rocks and so on?

There is one more conclusion which is really none of the above instruments are worth buying, some may be gimmicks and some may be too limited in scope of use or type of radiation capable of being detected. Since alpha would be almost impossible to detect unless you were directly on top of the sample, and beta would also be limited in penetration and you'd have to be very close, that leaves Gamma/Xray and Neutrons. Of course you'd still have no idea what isotope was causing the radiation (unless you knew details on the source) but at least you'd know what and where.

--- End quote ---

Let's just put it this way: If you encounter a nuclear incident that gets detected by one of those you are f***ed. A GM tube doesn't discriminate between different types of radiation, it is charged to a point where any extra energy that gets put in triggers a discharge of the entire tube-> that's why they are so pouplar and why they "click": The discharge is strong enough (and uniform as the entire tube discharges every single time) to power a loudspeaker. The only way you would detect something with a GM tube is when it significantly overpowers the natural background radiation->no bueno for you.

If you want to detect such events you need something that can discriminate between ions with different energies: That's a scintillator counter, and it is effing expensive (basically a orange sized monocrystal mounted on top of a photomultiplier).

Back to your GM counters: If you want to play around with it and see what emits radiation they are optimal, but you won't be able to detect radon and smoke alarms: All Radon isotopes decay via alpha radiation, the same goes for the Americium used in old smoke alarms: Only alpha, because they needed something that can ionize smoke particles-> let's just shoot them with really fat positive ions and hope they stick. Charged ions-> gamma is out. Alpha, because helium nuclei are way bigger than electrons.
edy:
Thanks for the explanations.... I started reading up on the difference and encountered this chapter on the web discussing GM vs Scintillation detectors to help me understand:

http://webfiles.ehs.ufl.edu/rssc_stdy_chp_4.pdf
helius:
I don't have the spare $ for such a toy, but if I did I would get a Gamma Scout ($400) or an Automess 6150AD ($400). These are the units used by bionerd23 in her videos at Chernobyl, and both have the ability to measure different types of radiation (gamma, beta, and alpha) either built-in (with the Gamma Scout), or using accessory probes (for the Automess).

Cheap geiger counters are generally gamma only, which has limitations since the "hot particles" ejected during a meltdown are alpha emitters. Another important point is that the counters that read in Rads or Rem are not going to be accurate with different isotopes. Dose-equivalents can only be calibrated for specific isotopes and not for unknowns. With unknowns, you are just looking for counts per minute as the detector cannot differentiate between events that trigger a discharge in the GM tube.

Scintillation detectors would seem to be less sensitive and less desirable, but the energy of the particle does change the output, so they can be built as spectrometers for profiling different isotopes.
jogri:

--- Quote from: helius on June 29, 2020, 08:32:57 pm ---I don't have the spare $ for such a toy, but if I did I would get a Gamma Scout ($400) or an Automess 6150AD ($400). These are the units used by bionerd23 in her videos at Chernobyl, and both have the ability to measure different types of radiation (gamma, beta, and alpha) either built-in (with the Gamma Scout), or using accessory probes (for the Automess).

Cheap geiger counters are generally gamma only, which has limitations since the "hot particles" ejected during a meltdown are alpha emitters.

--- End quote ---

Yeah, but you don't really need to measure alphas as they are only extremely dangerous when they are airborn and their concentration would be too low to be detected by normal alpha counters (unless you point it at a HEPA filter with a suction fan behind).
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod