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Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059
From the description given in the article I found involving a radioactive fossil in someone's desk, it would be in the uSv range. Certainly it only showed up on a newer counter, the older unit saw nothing.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
Conundrum wrote ...
From the description given in the article I found involving a radioactive fossil in someone's desk, it would be in the uSv range. Certainly it only showed up on a newer counter, the older unit saw nothing.
The highest dose rate I've ever seen from a mineral sample was just short of 100 uSv/hr gamma from a chunk of the best Cornish pitchblende. Most pitchblende samples give less than half that value.
Registered Member #59353
Joined: Sun Apr 17 2016, 02:08PM
Location: France
Posts: 84
Hello,
(my geiger counter is not compensated on energy, so you have to rely on CPM, not on USV / H.)
my piece contains a significant amount of uranium, and comes from a mine in the Czech Republic.
there are minerals with even higher radiation levels.
example: page 5/11 by an organization that doesn't depend on the government
Translation: Sometimes very important risks Verifying the level of gamma radiation near minerals is a useful precaution because in some cases, the risks may be significant. The highest level of radiation measured by CRIIRAD on minerals to date is for a piece of Uranium ore conserved by a resident of Saint-Priest-La-Prugne in the Loire, at its flowerbeds (see photograph below). The contact dose rate measured in July 2002 was 1 milliSievert per hour (Hp10 dose), 5,000 times higher than the natural background noise of the place. At the request of CRIIRAD, this sample was taken in charge by the former mining operator (COGEMA-AREVA).
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059
I should probably run some more tests, for this purpose a handful of Th welding rods or some Lo-Salt would work. If it saturates a Geiger counter then a laptop should not stand a chance. Depends on isotope of course as lower energy may increase error rate due to higher absorption in the silicon memory chips. Vent holes in the memory casing would increase dosage as well.
EDIT: I found the problem. Bad RAM can happen over time and yes this can make it super sensitive to radiation. So much so in fact that I could detect my proximity by the number of soft errors in the RAM test! Pauli effect IRL. This can also happen to HDD cache chips as well and can sometimes lead to data loss as even a clone will fail.
PaulL Well it was strong enough to detect on my unshielded SBM20 running at about 510V at 2" away (bag of enriched 40K) and when I tried it the RAM test failed in about an hour. At that point it got swapped out and replaced!
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Making a Geiger-Müller Counter
