RU_KLO
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Registered: 12-10-2022
Location: Argentina
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DIY Spinthariscope
I want to make a Spinthariscope based on a ZnS screen.
My idea:
1) Use a sheet of Zn, from a D carbon battery
2) Polish it
3) Paint it with nitric acid (by painting meaning a fine coating of nitric acid – not dipping in acid) as so to give a coating of zinc nitrate
4) Heating to convert the nitrate into ZnO.
5) Dipping this in thioacetamide solution – and heating (to convert the oxide into sulfide)
(maybe there is no need to go by the nitrate process, because Zn can react directly with thioacetamide to form the sulfide?)
This should be done in a neutral solution because acid tends to easily decompose zinc to produce bubbles of hydrogen (which will remove the ZnS
created layer)
(instead of thioacetamide:
1) A saturated solution of H2S in water
2) In a closed H2S atmosphere (jar like) - like lead acetate paper reacting with H2S gas.
Other options : instead of nitric + heat, use acetic acid to go to the acetate route, not heating.
Use a paper - better a black paper as ZnS is white... dipped and dried into zinc acetate then treat it with H2S gas....
Last step, put this sheet in a black closed box, with a magnifying lens.
As source of radioactivity, use the camping gas illuminating bag (I don’t know how to translate to English. We called “sol de noche”, attached a
picture. From high school I remember they are radioactive.
(other sources of alpha particles, old smoke detectors... but they seem difficult to get)
What are your thoughts, ideas? Will it work?
Go SAFE, because stupidity and bad Luck exist.
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chempyre235
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I believe it's called a gas mantle.
Alpha sources are generally hard to get for the amateur (at least in decent quantities), but your suggestions sound like good options. However, I
would rather get thoriated welding rods, as they are OTC in the US (I don't know what the rules/restrictions are in Argentina). The welding rods are
2% Th by weight, with most of the other 98% being titanium.
Another good option might be extraction from natural minerals.
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Sulaiman
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miscellaneous thoughts
A spinthariscope is fairly easy to make
and fascinating to use - for a little while.
your eyes need to be dark-adapted
virtually no one that you show it to will be interested
many that you show it to will be afraid of the radiation
---------------------------------
your vision needs to be dark adapted
so you (and anyone that you want to show it to) will need to be in very dim light for quite a few minutes before looking.
if I understand correctly,
in your scheme the radiation would have to pass through the zinc
which implies a more intense radioactive source - near your eyes.
I used a commercially manufactured activated ZnS screen because it was cheap via eBay only a couple of decades ago.
CAUTION : Hobby Chemist, not Professional or even Amateur
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Sir_Gawain
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A thoriated welding electrode produces barely detectable amounts of radiation due to most of it being blocked by the tungsten. Even the thorium oxide
lantern mantles will likely not produce enough radiation to be visible. I would recommend getting a radium clock hand for the source.
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wg48temp9
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Registered: 30-12-2018
Location: not so United Kingdom
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Apparently to get zinc sulphide to glow requires it to be very pure with only a few parts per million of an impurity such as silver, copper or
manganese.
I recall one experimenter having to recrystallise his raw materials several times, then specifically dope it with a very small amount of impurity.
Perhaps you could use the phosphor extracted of an old florescent tube. Apparently, modern phosphors are more intense than zinc sulphide.
If you google "DIY glow in the dark powder" you will get several ads for phosphors and instructions for making them.
Here is a link to a YouTube video of a guy making zinc sulphide doped with copper phosphor that glows green: https://youtu.be/NGdVCIGHeQE?si=CgvJuOdU_Ygwa0Dv
[Edited on 5/31/2025 by wg48temp9]
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Sulaiman
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Posts: 3899
Registered: 8-2-2015
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if available, the americium capsule from a smoke alarm works really well.
too close to the ZnS screen and you get a large blurry blob of light
at a few cm in air the display is dimmer but more interesting.
if ZnS screens are not available then there is an opportunity for an enterprising chemist.
You may want to consider a naked video camera sensor as a radiation sensor
I've not tried but many have.
(due to societal, procurement and safety concerns I stopped playing with radiation decades ago)
Much nicer to observe on a large screen - far from the source of ionising radiation
and easier to shield against ambient light.
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PS I have an old (1997) unused untested Hamamatsu R1414 PMT if any member wants it for the cost of postage from Malaysia,
and a promise that you will try to use it - not just for resale.
IMPORTANT: Americium capsules from old smoke detectors are a good alpha source
- and a significant gamma and beta source.
+1 for getting the phosphor from a broken fluorescent lamp etc.
[Edited on 31-5-2025 by Sulaiman]
CAUTION : Hobby Chemist, not Professional or even Amateur
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