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A question for those knowledgeable about radioactivity

Seoul_lasers

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Density blocks gamma radiation basically, it's just the amount of mass per square meter of ordinary materials that makes the difference. Since lead is very dense and inexpensive it is often the material of choice, especially for small setups. On larger installations one can rely on thick concrete walls and such instead.

Alpha radiation is very easy to block as it is, no special materials required there.

But with beta radiation things change a bit - high-atomic-mass materials like lead don't really work that well here. They do block the beta radiation, but re-emit part of the energy as x-rays which are still ionizing and dangerous.

For work with pure beta emitters, the safety equipment usually is not shielding by lead, but by half an inch thick perspex or something similar to that. You'll find equipment like that in any radiological lab that works with pure beta emitters.
Yes, and you'd be right on Beta electrons causing secondary emissions. This is why when making shielding, one laminates a number of materials together so as to avoid the situation of X-ray emissions from the bremsstrahlung. Higher energy beta from Y90/Sr90 is particularly problematic in this situation.
Pb shielding, sandwiched between 2 thick Polyethylene plastic sheet material is able to take care of this effect nicely.

the high density polyethylene blocks the beta from getting to the Pb shield and additionally protects against high speed Neutrons as PE is a hydrocarbon, the Pb protects against the higher energy Gamma rays as it has a high Z (atomic number). Other materials with high Z factor are Ti,Cu, Cr, V, Fe
 
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Nordhavn

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When I needed small quantities of solid CO2 (dry ice), I would use a CO2 fire extinguisher. The same technique is used to freeze water in pipes to block flow for emergency repairs.

As far as traser/betalights, even handling raw sources out of an exit sign, has no real risk at the borosilicate via blocks all beta radiation. Even if you cracked open the vial and inhaled H3 (not recommended obviously!) the overall dose wouldn't be that big AND you'd piss it out in a few days.
 

Blarg King

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It occurred to me I could also make a short lived cloud chamber by cooling the chamber by flipping a can of air duster upside down and spraying the propellant out. That stuff comes out at around -35 C, should be cold enough. I may try that this evening. If I did it outdoors it would probably last longer since its around -10 C.
 

cyberdoc

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Hi BK:

I made one centuries ago for a ninth grade science fair. I basically generated a vapor cloud by a sudden deflation of a balloon submerged in an isopropyl alcohol + black ink solution. I’d be happy to elaborate if you’d like. Thanks & Please Take Care. :)

- cd
 

Blarg King

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Welp my first attempt at a canned-air cloud chamber was a failure. I suspect a single can doesn't have that much capacity to cool off a large glass container. Might have to just build one with peltiers.
 

Seoul_lasers

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That is a VOLUME ratio. If you don't understand the difference between volume and mass, I can't help you further.

The ratio posted is a volume based on the Z rating. Yes.

Ch. 8 of Introduction to Radiological Physics and Radiation Dosimetry by Frank Attix does a good job of explaining stopping power and mass stopping power. The mass stopping power is dependent on properties of both the incident particle and the medium. The mass stopping power is directly proportional to the atomic number of the medium and the square of the charge of the incident particle, and inversely proportional to the atomic mass of the medium and the square of the beta value of the incident particle.


Thank you. This is what I was trying to get at the first time. See above :can:
 
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Encap

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Hmm...
From a DIY tritium battery to a cloud chamber...:pop:

Jerry
:pop:
I am still trying to figure out why anyone would want an useless, ugly, and dangerous radioactive rock in a lead lined ammo box in their closet? :crackup:

Who knows, maybe to go next to a "hobby" box of the 5 commonly known most extreme toxic substances one can acquire.
1. Botulinum toxins --The LD50 values reported for the commonly known seven proteins are about 5 ng/kg. There is an eighth, Type H, discovered recently in stool samples of an infant with botulism. It takes an injection of just 2 billionths of a gram or inhaling 13 billionths of a gram to kill an adult.

2. Snake venoms --most snake venoms are a mixture of many proteins which are often neurotoxins with LD50s below 1 mg/kg.

3. Arsenic --Elemental arsenic has an LD50 of around 13 mg/kg – orders of magnitude higher than some of the substances on this list. Despite that, the Agency for Toxic Substances and Disease Registry gives it the top rank on its priority list of hazardous substances.

4. Polonium-210 --The radioisotope used to kill Alexander Litvinenko is extraordinarily toxic even in quantities less than a billionth of a gram.

5.Mercury - the toxicity of mercury depends critically upon the kind of mercury involved. Organic and inorganic mercury compounds have different effects and hence LD50 values (which are typically between 1mg/kg and 100 mg/kg)
 
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Blarg King

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If you read this thread then you would know it isn't dangerous at all. You can make any hobby look stupid with ease. Hobbies don't have to have universal appeal.

Addition: You're trying to understand why I keep a box of radioactive stuff on a forum where people spend hundreds of dollars on machines whose sole purpose is to make beams of colored light that have only a few niche uses for hobbyists.

Hmm...
From a DIY tritium battery to a cloud chamber...:pop:

Jerry
What can I say? An idea I had spawned an enjoyable conversation about radioactivity in general. Nobody I know IRL gives much care to discuss it so might as well discuss it here and run ideas by people more knowledgeable than myself.
 
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Seoul_lasers

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:pop:
I am still trying to figure out why anyone would want an useless, ugly, and dangerous radioactive rock in a lead lined ammo box in their closet? :crackup:

Who knows, maybe to go next to a "hobby" box of the 5 commonly known most extreme toxic substances one can acquire.
1. Botulinum toxins --The LD50 values reported for the commonly known seven proteins are about 5 ng/kg. There is an eighth, Type H, discovered recently in stool samples of an infant with botulism. It takes an injection of just 2 billionths of a gram or inhaling 13 billionths of a gram to kill an adult.

2. Snake venoms --most snake venoms are a mixture of many proteins which are often neurotoxins with LD50s below 1 mg/kg.

3. Arsenic --Elemental arsenic has an LD50 of around 13 mg/kg – orders of magnitude higher than some of the substances on this list. Despite that, the Agency for Toxic Substances and Disease Registry gives it the top rank on its priority list of hazardous substances.

4. Polonium-210 --The radioisotope used to kill Alexander Litvinenko is extraordinarily toxic even in quantities less than a billionth of a gram.

5.Mercury - the toxicity of mercury depends critically upon the kind of mercury involved. Organic and inorganic mercury compounds have different effects and hence LD50 values (which are typically between 1mg/kg and 100 mg/kg)
I too have a quite a radioactive "collection" and it dual purposes as a reference source for gamma spectroscopy, ( also to show to students when I am talking about nuclear related topics or light and energy/ not to mention some of the specimens are highly collectable. :evil:

Nothing useless or ugly. I guess it depends on what value.
 

paul1598419

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I had some rocks in my collection that on the surface, seemed quite ordinary. But, they were often chemically significant, so I saw beauty in them even if others did not. I have known about your radiation spectroscopy projects for some time now and have followed them for maybe a couple of years now, Seoul_lasers. I have found it all very interesting and hope you continue to post about it.
 

Seoul_lasers

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Some of the most insignificant looking things can turn out to have the most interesting stories to tell. Looks are usually deceiving.

BTW--> My Bircon surveyor MS got it's new board installation today. I had to epoxy it onto the back of the analog panel meter. This will give the ability for the unit to be seen on Ti LabView over a network.

the case for the external meter from RHElectonics comes from Ankara, Turkey next week. Will be showing it off in the Bicron Surveyor MS mod thread.
 




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