Tactical Nuclear Warhead Made From Smoke Detectors
Many people don't realize this but most smoke detectors contain an artificially produced radioisotope: americium-241. Americium-241 is made in nuclear reactors, and is a decay product of plutonium-241. This radioisotope can be used as the fissionable material in a homemade nuclear warhead. I will outline the details of how to make your own nuclear weapon on this page.
First some background:
The key component in household smoke detectors is a small quantity of americium-241. This element was discovered 50 years ago during the Manhattan Project. The first sample of americium was produced by bombarding plutonium with neutrons in a nuclear reactor at the University of Chicago.
Americium-241 emits alpha particles and gamma rays. The alpha particles are absorbed within the smoke detector, while most of the gamma rays escape harmlessly. The alpha particles emitted by the Am-241 collide with the oxygen and nitrogen in the air in the detector's ionization chamber to produce charged particles called ions. An electric voltage applied across the chamber is used to collect these ions, causing a steady small electric current to flow between two electrodes. When smoke enters the space between the electrodes, the alpha radiation is absorbed by smoke particles. This causes the rate of ionization of the air and therefore the electric current to fall, which sets off the alarm.
The amount of Americium in a smoke detector is small - about 1/2 gram. And the amount of Americium-241 required to form a critical mass - about 750 grams - is large by comparison, yet if you collect enough smoke detectors it IS possible to accumulate enough of the stuff to make a tactical nuclear warhead. A quick calculation would indicate that 1500 smoke detectors are required, but because of impurities and unavoidable inefficiencies in a homemade design, you will want at least 2000.
I guess I should put in a disclaimer here so I don't get sued:
Americium-241 is a potentially dangerous isotope if it is taken into the body in soluble form. It decays by both alpha activity and gamma emissions and it would concentrate in the skeleton. Also, constructing a home-built nuclear weapon has many obvious risks to yourself and to the people in your community. If you decide to go ahead with this: DO SO AT YOUR OWN RISK!
OK, down to business. First of all how can an average person afford to buy 2000 smoke detectors? At about $20.00 each that would be about $40,000! Let me give you a little secret: The half-life of Americium-241 is 432 years. Old discarded smoke detectors work just as well as brand new ones! Still, getting 2000 discarded detectors may seem like a daunting task. Here is how I did it: The best place to find detectors is at your local dump. I have combed through the garbage heaps at my local dump every Sunday for the past two and a half years. I have found an average of 15 smoke detectors in the four hours or so that I spend there every week. I never found less than five, and one memorable day I came home with almost 40!
Once you have your smoke detectors, you need to separate the fissionable material from the plastic and metal of the detector. You will quickly get the hang of this, and it shouldn't take you more than one or two minutes each. One word of caution here: Do not keep your Americium in one big container! Remember – a nuclear bomb is detonated by bringing enough fissionable material into close enough proximity with itself, to create a "critical mass". I don't think you will be wanting to create an unintentional critical mass in your sock drawer, so keep it in separate containers, and keep the containers well apart.
When you have collected and separated your Americium-241, you will be ready for the actual construction of the bomb. First, you will need to prepare the two masses of americium so that each of these sub-critical masses can be brought together rapidly into one super-critical mass that will sustain a runaway nuclear chain reaction. The best shape for the critical mass is a sphere, so one logical configuration would be two half-spheres. This is just what I did. I found that a tennis ball makes a great mold, and it's the perfect size. Cut it in half, and put half of your americium in each side of the ball. Use an epoxy or similar glue to hold the particles of americium together. I used Elmers non-toxic paste, and it worked great.
Now we have to figure out how to bring these two half-spheres together and hold them together long enough for the chain reaction to take place. If they are not held together long enough you will probably still get a blinding flash and searing heat but no real explosive power - in other words, a dud.
For you technical types, here is the formula for the power required to bring these masses together violently enough to ensure a chain reaction: g(l-CmCl)sin +K*(Pi-Omega)/L1(1+CmCl2). This works out to the explosive power of about 1/20 of a stick of dynamite, or the power of one common M-80. M-80s are like giant firecrackers, and they are usually available around the Fourth of July. They are not legal in most states, but if you have ever heard those big explosions in the distance on the Fourth, you can bet it's some kids who have gotten a hold of some of these. You may have to hunt around a bit, but you should be able to find them.
Now you will need to collect some common materials to make your warhead. You will need a two foot length of 2.5" diameter pipe, Two screw-on end caps for the pipe, a can of frozen concentrate orange juice, and some common hand tools.
Glue one of your sub-critical masses into one of the end caps. Screw this onto the pipe. Glue the M-80 into the other end cap, and pass the fuse through a drilled hole in the cap. Now we could just glue the other sub-critical mass on top of the M-80, screw the end cap on light the fuse, and hope for the best, but this probably won't work because we want the two halves of the Americium-filled tennis balls to come together with the flat sides facing each other. Here is how you can guarantee that happens: Make sure the can of frozen concentrate orange juice slides nicely in the pipe. If not, use some other canned food like tomato paste. Then glue the second half of the tennis ball (flat side out), to your canned food. Now, when the can slides down the pipe, it will keep the tennis ball properly oriented. You should glue the can to the M-80 to hold it apart from the other sub-critical mass until you are ready to trigger your device. Screw the second end cap on securely, and you have your bomb!
Obviously, a 20-second fuse is not long enough for you to get away to a safe distance if a weapon like this were ever detonated. Three miles is the minimum safe distance from an explosion of this size. One solution is the powerful missiles available to the model rocketry hobbyist. I have constructed a five foot long rocket using components that are available from Earl’s Hobby and Crafts at: http://www.earles-hobby.com. This rocket should be powerful enough to carry a payload the size of the warhead at least three miles. This would be plenty for a small bomb like this, but I would make sure you use some very dark sunglasses, or welder’s goggles, if you plan to observe a nuclear fireball.
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