see atomic particles with your own eyes

So you wanna see atomic particles with your own eyes huh? Here's how to do it easily!

Just build a nuclear cloud chamber...for around $7.

Cloud chambers let you see paths left by radioactive particles as they pass through a supersaturation of alcohol vapor. Vapor trails are formed when the radiation ionizes the alcohol mist super-cooled and formed by dry ice under the aquarium while the top of the aquarium drizzles the propanol (very pure rubbing alcohol you must never touch, or Everclear grain alcohol would probably work, as would methyl alcohol like Heet fuel additive). I went with a $7 bottle of 99.9% pure rubbing alcohol. Caution: the 70% stuff at drugstores won't work.

Alpha particles, and beta and gamma rays leave different looking trails in the mist; as do muons, positrons, cosmic rays, electron collisions;--basically ions. X-rays, bremsstrahlung (braking) radiation and annihilation radiation arising from positrons interacting with electrons basically behave like gamma rays.  Some trails are long and thin, some are short and fat, some branch out like lightening: each path can tell you the exact type of particle that just whizzed by! Yes, you can actually see the tracks they rip through the mist. You can even use a strong magnet and "bend" the path of some particles.

What I used: 10 gallon aquarium; metal roof flashing; stiff wire/coat hangers; styrofoam block; socks; wire to use as tie-wraps; 99.9% rubbing alcholol; DRY ICE and some radioisotope AM-241 from an ionic chamber type smoke detector ($5 at any store). AM-241 is Americium (pronounced Amer-eh-SHE-um). You'll see the Am-241 in the video, it's just a flat silver disk that is INSANELY RADIOACTIVE, yet it mostly shoots out 

Don't get confused AM has a number of 95 on the Periodic Table, but this is one of its isotopes (241). Am-241 is so radioactive that all the "harmless" alpha particles is shoots out are so plentiful it actually damages the crystal structure of the element itself! This is like the damage that radioactive particles can do to your DNA to cause cancer. In addition to tons of alpha particles it also emits some gamma particles as well. My Geiger counter can't see alpha particles--just beta, gamma and x-rays and even so it reads around 300 clicks per minute! 

MANY PEOPLE ONLINE SAY THAT AM-241 FROM A SMOKE DETECTOR ONLY PUTS OUT A FEW GAMMA PARTICLES AND THE REST IS SAFE ALPHA. THEY OBVIOUSLY DON'T OWN GEIGER COUNTERS AND CANNOT ANSWER WHEN YOU ASK THEM TO QUANTIFY THE GAMMA RADIATION. 

So do your own homework, buy a $99 Geiger counter (I use a GQ GMC-300e Plus) and don't believe everything on the internet, it can get you killed. At 300cpm what is dangerous gamma particles in this piece of AM-241 is only slightly worse than two of my old glow-in-the-dark wristwatches from the 1930s. Still, the danger is there.

BUILDING THE BEAST

Here's how I did it. Cut a recess in a foam block to hold the dry ice.

Make a wire frame inside an aquarium to hold the socks that we'll douse with 99.9% rubbing alcohol. The long pieces will go near the glass bottom. The aquarium will be upside down with the socks at the top when the unit is working.

Put the socks on and tie them with thin wire. Rubber bands will melt from the alcohol and break from the dry ice. Just use wire bread bag wraps if that's all you can find.

The aquarium's glass bottom is now it's glass top.

I fit the the aquarium on the glass block so it was air-tight and put a piece of THIN metal roof flashing between the dry ice and the inside of the cloud chamber. It looks black here because I had it covered, but it didn't work so I uncovered it. In the video it's bright shiny metal.

I put the dry ice in the hollowed out recess in the foam block. I doused the socks with alcohol. Put the AM-241 on the metal plate. I put the metal plate on the dry ice and the aquarium over everything.

Next I added a light bulb on top of the glass carefully since these 99.9% alcohol vapors are highly inflammable. The light bulb was to add WARMTH to the top of the aquarium while the bottom was super-cooled by the dry ice. This creates the fog of alcohol vapors at the bottom for the particles to leave trails through.

In the video (which gets better halfway through because I re-position the light) you'll see a half-sphere dome of fog over the AM-241 disk and a flower-like cascade of alpha particle trails shooting off the disk. The unit only worked for about 10 minutes after 2 hours of trying. Oddly, even though everyone says it needs to be airtight--the unit only started working once I gave up and started to dismantle it. Once some warmer air hit the inside the fog formed and I started seeing trails!

This could mean that the whole aquarium was too cold. At one point I put a bucket of hot water on top of the aquarium to increase the temperature differential, but it didn't seem to help. I filmed it for a few seconds, and then spent a few minutes silently watching with a smile on my face. 

Almost everything I scavenged for free, including the smoke detector's AM-241. The 99.9% rubbing alcohol was $7 and all gone when I was done. I got the dry ice from the Melvindale Public Library where I work: we had an open house and children's bookmark drawing award ceremony and we had dry ice left over from the ice cream we served. I knew that we'd have dry ice left over, so I ordered the alcohol and built the nuclear cloud chamber a couple weeks before the event. So I guess this is a $7 cloud chamber.

And that's how you can "see" atomic particles. It's a lot more fun than those golf-ball diagrams in your textbooks and tinker toy balls and connectors: like Coca-Cola this is the REAL THING; and it won't give you cavities...but it might give you radiation poisoning...

Yes, you can get great deals on Uranium these days

Yes, you can get great deals on Uranium these days

My (smallest) Geiger counter is a GQ GMC-300e that was $99. It reads beta, gamma and xray radiation. It doesn't do alpha, if it did then this Uranium sample from Lisbon Valley Utah would be about 40% higher! The video was short because as the Geiger got so hot I wanted to move away at high speed.

The final reading was 6200 clicks per minute. My antique radium painted wristwatch was only 220cpm or so! These are very, very hot rocks-like that old film noir movie "Kiss Me Deadly" from the 50s, minus the howling noise.

No relation to the awesome Lita Ford song of the same name.

This sample is unrefined uranium ore. I've tested a few old wristwatches and found Radium in them. Back in the old days companies would paint Radium on watches and clocks and other things to make them glow in the dark! A lot of workers who did the painting died awful deaths, but not before developing disfiguring tumors. A famous group are known as the "Radium Girls" who would purse their lips on their paintbrushes to get a real fine, pointed tip to paint the clock faces with more precision. Turns out putting radioactive brushes in your mouth is a bad idea. Radium is very similar to calcium, it has a bad habit of swapping places with the calcium in your bones and causing massive health problems.


Alpha particles are stopped by your skin. Even a sheet of paper will stop them so Geiger counters that can detect alpha radiation are more open and this fragile: the plastic case on my Geiger is more than enough to block all alpha even if it was sensitive to it. To stop beta radiation you'd need a sheet of aluminum. Gamma and x-rays blast through all sorts of things but are significantly stopped (but not totally) by lead. Surprisingly, scientists disagree on the definition of what constitutes gamma vs X-rays.

I got interested in radioactive things when I fixed an old antique watch. I fell asleep with it on and in the dark noticed that the hands weren't "glowing" but we're actually sparkling! It was so weird that I researched and found that the watch was painted with Radium. On the bottom of the face near the 6 o'clock position was a tiny "Ra" that could only be seem with a magnifying glass. Ra=Radium. Deadly, deadly radium.

After getting me Geiger counter I found another, unlabeled, watch that was even more radioactive in my collection.


Recently I ordered the uraninite ore from LifeTech and they sent it out properly packed and with no problems. It is way more radioactive than my old wristwatches.

So, besides listening to the tell-tale clicking of the Geiger counter what can you do with radioactive minerals and such? Well, my next post will be about the cool Nuclear Cloud Chamber that let's you see the trails left by the path of radioactive particles zinging through a cloud of supercooled alcohol vapor-the best part of that it is super cheap and easy to make!

How did I get interested in radioactive stuff? Well, shown above are my gold Lord Elgin Swiss watch with Radium glowing hands and hour markers and a Uranium laced glass marble. I got the watch for free in a box of 'junk' at a garage sale. I fell asleep while wearing it and in the darkness brought it up to my eyes to see. It was then I noticed that it wasn't just 'glowing' in the dark it was 'sparkling'!!!! This sparkling was a scintillation every few seconds, like a weird mini-lightening strike: kind of slow, like when a big lightening bolt takes a while to branch out in the sky. I did a little research and found out my cool gold watch was radioactive--and the reason it was is that the hands were painted with Radium, sometimes written near the 6 o'clock position as 'Ra'.

The Uranium glass marble changes color in sunlight due to, well: Uranium in the glass. Many antique (and new) glass contains Uranium for this color-changing effect. Uranium glass is also called "Vaseline Glass". It's all slightly radioactive. So are thorium laced gas lantern mantles for camping. The little sock looking wick is radioactive. 

Fiestaware ceramic bowls and plates (especially the red colored ones) are so radioactive that people break them into pieces and sell them to Geiger counter owners like me as a test source!

Name      What is it?                                                                           Distance traveled 
                                                                                                                    through open air
Alpha       Physical particle equaling a Helium nucleus                        2-3cm

Beta          Physical particle equaling an electron                                    2-3m

Gamma    Not radioactive decay, just energy burst                                500m
                   accompanying alpha or beta radiation.
                   The same as an x-ray, but arising from
                   different sources.

Neutron     Physical particle made up of 1 up quark and                   1000s of meters
                     2 down quarks.


Name   Symbol     Makeup                           Charge         Speed       Atomic Mass Units
Alpha     α             2 protons & 2 Neutrons       + +                Slow                               4

Beta        β               1 electron                                -              Fast or Slow                1/2000

Gamma  γ                Photons/                           Neutral        Speed of light                   0
                           electromagnetic waves

Neutron n           1 up & 2 down quarks         Neutral      2.2km/S-14,000km/S         1
                                                                                                 (~5% speed of light)

Notes: 

An AMU (Atomic Mass Unit) is equal to 1/12 the mass of a Carbon-12 atom. 

Slow Neutrons are called "Thermal" and fast ones are called "Fast" neutrons. 

An alpha particle is double positive "++". 

Gamma rays are produced by atomic nuclei and x-rays are created by accelerating electrons, but they are basically the same type of wave energy. 


Lead only approximately halves the gamma/x-ray amounts. A 1/2" of lead stops about half the waves trying to get through. When beta radiation hits lead sometimes a new type of radiation is created that is more dangerous! This is Bremsstrahlung radiation (braking/deceleration). Lead barely interacts with neutron radiation, water or hydrogen-containing compounds such as common paraffin wax are much better shielding material.


By the way, another great place to creep around and find info like this is the Oak Ridge National Lab at  https://libcat.ornl.gov/  which has tons of DECLASSIFIED reports of various techniques for radioactive fun. The directory names look like years, but the files inside them are all scrambled up--so just poke around. A cool file I found was "The Preparation, Properties, and Uses of Americium - 241, Alpha-, Gamma-, and Neutron Sources."