While there are ion chambers in smoke detectors that use a radioisotope, I was referring to an ion chamber designed to measure radiation.
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While I probably have more then a dozen "professional" articles in ion chambers, Charles Wenzel gets down to the practical "This is how you can build them." [And his work!]
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https://techlib.com/science/ion.html
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Alpha, Beta, and Gamma all produce ions as they pass through "air" [Neutrons not so much] and Ionized air is conductive. [slightly]
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It is easy peasy to build an ion chamber, really REALLY difficult to accurately calibrate them. The old Civil Defense units were off by up to 200%.
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Your dipping a Geiger Muller tube into wax is interesting, not as effective as lining the tube with boron.
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This video shows the effect I was referring to.
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Back in 1975ish, we called it 'dead time,' today it is called "foldback."
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https://www.youtube.com/watch?v=afBrwo96jV8&t=417s
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Note how the count increases then drops off. Not quite what one would expect from the inverse square law.
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Note 1: DO NOT PLAY WITH DRY LOOSE RADIUM PAINT UNLESS YOU WISH TO DIE A HORRIBLE DEATH OF LUNG CANCER! Don't scrape it off clock faces or hands or the needles in some military meters either!
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My best, as in most intense, radiation sample is a 0-1mA analog meter from some obscure, long forgotten, piece of military test equipment.
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It is stored outside with my uranium and thorium oar samples, and a pack of 36 Coleman lantern mantles from 1970ish, also stored outside.
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Pre 1980ish Coleman lantern mantles had thorium oxide and are reasonably "hot." Not sure I like the idea of lighting silk impregnated with thorium, some thorium has to escape and you get to breath some....
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They now use a rare earth. [After I tossed my Coleman lanterns in the trash. Bummer, but LED lanterns are fun to design and build!]
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Some welding rods have [?had?] thorium....quite a bit, fairly hot, and trust me, you get some really odd looks when you go into a welding supply company with a Geiger Counter as a 9th grader to get a radioactive sample for a science project.
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I used a fume hood at the university to crumble the 'stuff' off the thorium welding rods into a plastic 35mm film cartridge case.
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I glued on the top to keep things safe.
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[Hey I was 15 and my concept of safe might have left a bit to be desired.]
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The science teacher freaked out when she checked the radiation level from my sample as in..."My God Terry! Where did you get this?"
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"Made it from thorium welding rods."
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"I think I'll take this for safe keeping."
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I'd intended to demonstrate the inverse square law. I received an "A" but wasn't allowed to do the demonstration.
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She called my mother who nixed further thorium welding rod radioactive samples. Bummer.
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Note 2: Proof one can get a bit too much into their hobby. This guy has way too much radiation in his life. Surprised he hasn't moved to Chernobyl.
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And
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https://www.youtube.com/shorts/51DsRaUtuns?app=desktop
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Different Geiger Muller tubes and circuitry have?different responses to radiation overload. Enough gamma will overload any GM tube. Some fancier systems have secondary sensors to indicate "extremely high radiation levels." Some special silicon diodes are perfect, their leakage goes up extremely rapidly when the gamma or neutron flux is above some level. [I've never studied this in detail because I'll never be in such intense radiation fields.]
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Another option is to include a small ion chamber. During normal operation the small ion chamber's conductivity due to radiation ionization is minimal, at high levels the ionization increases dramatically, increasing the conductivity, giving a warning "your GM tube is overloaded." [Simple in concept, I suspect it'd turn into a design nightmare in practice.]
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Oh, and as a child my dinner plate was a bright red Fiestaware. The red was caused by uranium oar. [That might explain a lot about me.]
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Mom's uncle was an engineer who never spoke of his work. He gave me a Geiger counter, yea at the age of 5 I owned a Geiger counter, it lit up with the Fiestaware.
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"Lit up?"
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Pegged the first 3 scales.
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https://www.orau.org/health-physics-museum/collection/consumer/ceramics/fiestaware.html
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"My" Fiestaware was pre-WWII.
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And Mom threw it away to keep me safe!
[If she only knew how futile that plan was!]
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I strongly suggest any Fiestaware, or similar glazed ceramics, be retired from use.
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To keep radiation safety in perspective, a person in a sea level city will receive ~300 millirems per year, a person in Denver will receive ~400 millirems per year.
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Aircraft crews typically receive?between 3 and 6 millisieverts (mSv)? 3000 and 6000 millirems
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1 mSv = 100 mrem.
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And I won't mention the 'gazillion' or so 'cosmic rays' that punch through us every moment of the day.
Yawn.
[Gazillion is hyperbole, a literary device, not hard science.]
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Oh, useless trivia, Tobacco concentrates ?polonium-210 and lead-210.
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There is a boatload of Uranium dissolved in the world's oceans. Limestone is the result of the remains of ancient sea critters. Their remains have uranium, true, trace amounts, but uranium. Radon in Kentucky comes from the decay products of the uranium deposited way back when.
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Polonuum-219 and led-210 are decay products, as is radium, as is radon. Some spots of limestone in Kentucky produce enough radon to be a real nightmare.
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Of course granite also has uranium, it decays and eventually produces radon. You can't win because the universe conspires against you
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For the truly demented, grab an ion chamber smoke detector. There is a small bit of American-241 in the non photoelectric detectors.
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That bit can be safely removed and used as a check source for Geiger Counters.
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There are youtube videos showing how to do this.
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My standard is a bit of American-241 that I check every year or so against NIST traceable instruments.
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I here someone wail, "But radioactive stuff is dangerous!"
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[Ion detectors have reduced the loss of life in house fires in the US by over 50%.]
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So why does my Civil Defense Geiger counter have a radiation check sources....that has long since decayed to barely detectable....
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"You're trying to tell me a device designed to detect dangerous radiation had a built in radioactive source?"
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"Yep. Deal with it."
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https://www.orau.org/health-physics-museum/collection/civil-defense/cdv-instruments/cdv-700-check-sources.html
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FWIW, The Cuban Missile Crisis happened when I was 12, in the 6th grade and left a deep impression on me. I took the civil defense shelter manager classes and was a certified shelter manager at the age of 16. I'm sure people would have listened to a 16 year old in a nuclear war. When they rolled CD into FEMA and shut down all the shelters, I ended up with Geiger Counters, dosimeters and ion chambers, all legally, I still have the paperwork.
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So I know a bit too much about radiation et al then probably is healthy.
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Oh a boring paper on Radon by the feds.
https://pubs.usgs.gov/gip/7000018/report.pdf
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I have oodles of papers, some require a Ph.D. in physics that I can't begin to comprehend.
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FWIW, Geiger Counters are fun to play with. Optimizing the high voltage inverter is a challenge, you want an extremely stable HV with the lowest practical current drain. This is generally the biggest current hog in a Geiger Counter.
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I have a pair of GM tubes mounted about 20 feet above the ground in water proof cases. They are designed to measure and record "cosmic rays." Designing a HV power supply that is stable, draws as little current as practical that will work over a 150 degree F temperature range was an interesting challenge.
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The weather in Kentucky can ranged from -130F to +120F. Yea the extremes are sooooo much fun.
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My active antennas do not like it when the temps drop below -5F. Cross modulation goes through the roof. Still working on that one.
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