Let´s build an isotope generator -the thorium cow
(after dr. klaus,thank you amigo)

-[радиоактивность] !!!

the isotope generator contains granular thorite, that contains nearly 70% thorium232.the thorium decays over some isotopes to radon220
(see here)

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the radon emanates the rocks as gas with a half-life of 55 seconds and then condensate to a solid element (polonium..after that lead..finaly stable lead208).
the device can be run in 2 modes:
the solid elements can be catched with electro-static field on a target to measure half life or scintillate (mode 1) or pump the gas over to circulate in
fluids or testing boxes (mode 2)

at first here are the most important ingredients:

small thorites, 60g, if you need a source i can tell you....ask me
little fan 12v,
70mm inox sieves (min 2 -max like you want, i build in 6),
a metal half-sphere from boss(R) parfume,
3mm threaded rod, plastic rod,
transformer 12v dc,
carbon tabs,
copper lace,
some 5mm alloy rivets as nozzles,
M5 screws,
the cheap (4$) 3wcree torch from ebay,
pattex repair or some other flexible glue
and a airtight containment ...
min 71mm diam. plastic storage cylinder (not on picture)

also needed: geiger counter, drilling and grinding machine (multitool) with cutting blade, high voltage source when using a target,
cpu fan holder ring, leds, when buying the sieves, pay attention that the will fit one in one and have a closed rim, they must savely
hold the thorite granulate (1mm granular size is ok, smaller size will result in dust)

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construction:

-at first cut off the handles from the sieves with high speed cuting wheel and cut out a gap left and right at the rim ,the threaded rods must fit in the gaps,
then bend the rim near the gap a bit down-nuts will fit better


-screw on the fan on the base (the base is the top cap of the containment), must have space beyond and blow the air upwards
-power on led: glue on some smd leds to the fan, solder on the wires- the leds will light on when the device is running
-drill 2 holes (but dont bore through)!! in the base to put in the 2 rods
-screw a nut and washer on the rods and put one sieve on it..screw another nut to fasten it...then one by one to get a tower of sieves


-drill 2 holes in the base to pass the cables out of the containment (one from upside one from the side) glue 2 rivets in the holes- this hole must be filled airtight at the end
of construction period


- cut the torch body in half ,the piece with the screwed-head (where the led was in) is the lock and the sample holder on the top of the contraption
- drill a bigger hole at the top of containment - the torch body must glued on airtight, screwed led head outside
-drill a hole through the led head (cap) and glue on a rivet (with isolation between), fill with 2k glue -must be airtight
-the target holder: carbon tab glued on rivet-rivet stuck in plastic rod,inside plastic rod a copper lace is connected with: threaded 5mm rod on the other end of
the plastic rod-this screwed in the rivet on the cap


-drill 2 holes on the half-circle sides to build on 2 straps of copper lace
-glue on the half circle to the inner top of the containment - it acts as collector


-screw on a cpu fan holder ring under the base- makes some space u can use to store the high voltage circuit

on the upper photo the carbon tab is screwed in-high voltage can be applied (2kv) and after beta(-) decay
the positive protos will go to the negative tab, sieves and the collector are connected by the copper laces

on this photo a silicone hose can applied to the top rivet -with a small pump radon gas can be pumped to external containers and from there back to the rivet at the back

high voltage is generated by a small ccfl inverter (40khz ac output) and a two stage half-wave series voltage multiplier (villard cascade)
output is ~ 1200V DC

if the fan and inverter is powered by a single dc 12v source, a diode must be soldered on the inverter input


crushing the thorites is done..outside in the wood with hammer on a stone,the thorites are filled in groups of 4..6 in plastic bags,
hammering and filled in another plastic bag..wearing gloves is recommended-and don´t never ever do this job in your house/flat

finaly the granulated thorites are strained with one of the sieves (had a spare part)

generator@work: now i must wait some days for a balanced out decay chain (and enough radon)
the geigercounter diy-kit on the photo is engineered by alex ( http://radiohobbystore.com )

1st video: 24h after filling in the thorites the radon builds up an radioactive athmosphere and start the decay chain to a balanced state
inside the jar .....that will be done in 6..7..days WATCH

just strapped some thick sticky double sided silicone 3M tape around the gap at the wooden base plate and acrylic top in case some
radon would escape through the seal lids

 

the 2nd mode

collecting isotopes on the carbon tab is sometimes boring, so the generator can be used as a source

i build up a small air pump, pumps can be found in wrist blood pressure devices for cheap, runs at 4,5V , pressure max 0,4bar
the pump is build in a plastic bottle with vibration canceling rubber ,air is pumped with a silicone hose into the generator at the back,
air esapes the generator on the top to a e.g. test-jar and from test jar back to the pump

update: the testchamber connected to the generator ,between them the airpump,notice the filter at the back (output) of the chamber

 

eof