Nulcear weapons - frighteningly simple

JupiterKid

I was reading upo on wiki anbout the development of nuclear bombs since it was the 65th anniversary of the Hiroshima bombing.

Most of us who are old enough to remember the threat of nuclear holocaust destroying the entire world which was very real until the early 1990s (and still is today with rogue nations like Iran and North Korea) will have heard of the ultimate and most destructive weapon built by humankind, the nuclear bomb.

The first nuclear bomb was detonated in July 1945 in New Mexico, USA. It unleashed a power even its creators never dreamed of. But what are the exact mechanics of the atomic bomb? Most people would assume these weapons to be highly complex devices.

In truth, they are frighteningly simple. The atomic bomb that was dropped on Hiroshima, Japan in 1945 instantly ended around 100,000 lives.:(

All it required was a device that could create a critical mass of the radioactive element Uranium 235 in an instant. The bomb was devastatingly straightforward in design. It effectively was a trigger and gun device whereby an amount of uranium that could potentially explode in a nuclear detonation (called a critical mass) was created through a device whereby a bullet of Uranuim 235 was fired into a pit of more Uranium which, when they met, caused a nuclear explosion.

Terrorists could easily create such a bomb - the only limit is the availablility of enriched Uranium 235 which is costly and difficult to manufacture.


Methods used to achieve nuclear bomb detonation. Creation of a critical mass of uranium/plutonium either by gun or implosion method.





In the early 1950s, scientists took nuclear weapons a significant step further, by developing the hydrogen bomb. Unlike using fission, or the splitting of atoms of radioactve materials such as uranium and plutonium to act as the explosive, the hydrogen bomb uses the fusion of the heavy isotopes of hydrogen, deutrium and tritium, to cause an explosion of a magnitude many times more powerful than the Hiroshima explosion.


Hydrogen bomb test in the 1960s




The hydrogen bomb is capable of far more destruction than a fission bomb (like the one dropped on Hiroshima) and in fact has the potential to annihilate huge cities like London, New York or Paris in one go, with the potential to kill tens of millions.

It seems to me that these bombs are not nearly as complex or as diffucult to build with the right technical know-how. That's a very frightening thought...

Turtwig

I was once told that you need at least eight different types of specialists to build a nuke. I know it's anecdotal, but there's no way in hell I'm typing "building a n..." into Google.

Terry

Malty_T wrote: »

I was once told that you need at least eight different types of specialists to build a nuke. I know it's anecdotal, but there's no way in hell I'm typing "building a n..." into Google.

I googled it. Here you go:

We will look today at what you need in order to make a nuclear fission bomb. You need some money, as it would really help
if you were the prince, sultan or other royalty of a small, but rich state. If not, you need to know on a first name basis some evil leader with lots of cash, oil, diamonds and so on, of a small but ambitious country, with a need for revenge on the world.

Step 1 - What is a nuclear fission bomb?

Fission bombs derive their power from nuclear fission, where heavy nuclei (uranium or plutonium) are bombarded by neutrons and split into lighter elements, more neutrons and energy. These newly liberated neutrons then bombard other nuclei, which then split and bombard other nuclei, and so on, creating a nuclear chain reaction which releases large amounts of energy. These are historically called atomic bombs, atom bombs, or A-bombs, though this name is not precise due to the fact that chemical reactions release energy from atomic bonds (excluding bonds between nuclei) and fusion is no less atomic than fission. Despite this possible confusion, the term atom bomb has still been generally accepted to refer specifically to nuclear weapons and most commonly to pure fission devices.

Step 2 - What do you need?

a. The fissionable material

Plutonium239 isotope. Around 25 pounds (10 kg) would be enough. If you could find some Uranium235, that would be good, but not great. You would need to refine it using a gas centrifuge. The uranium hexafluoride gas is piped in a cylinder, which is then spun at high speed. The rotation causes a centrifugal force that leaves the heavier U-238 isotopes at the outside of the cylinder, while the lighter U-235 isotopes are left at the center. The process is repeated many times over through a cascade of centrifuges to create uranium of the desired level of enrichment. To be used as the fissile core of a nuclear weapon, the uranium has to be enriched to more than 90 per cent and be produced in large quantities.

You could try buying it from a former Soviet Republic, or from Iran, since they're trying so hard to produce it. North Korea is not ready yet, and unfortunately, Iraqi dealers retired from the business.

b. The explosive to start the nuclear chain reaction

100 pounds (44 kg) of trinitrotoluene (TNT). Gelignite (an explosive material consisting of collodion-cotton (a type of nitrocellulose or gun cotton) dissolved in nitroglycerine and mixed with wood pulp and sodium or potassium nitrate) would be better. Semtex would be good too, but it's a bit hard to get, these days.

c. The detonator

To fabricate a detonator for the device, get a radio controlled (RC) servo mechanism, as found in RC model airplanes and cars. With a modicum of effort, a remote plunger can be made that will strike a detonator cap to effect a small explosion. These detonation caps can be found in the electrical supply section of your local supermarket. If you're an electronics wiz, you should be able to make it using a cellphone.

d. The pusher

The explosion shock wave might be of such short duration that only a fraction of the pit is compressed at any instant as it passes through it. A pusher shell made out of low density metal such as aluminium, beryllium, or an alloy of the two metals (aluminium being easier and safer to shape but beryllium reflecting neutrons back into the core) may be needed and is located between the explosive lens and the tamper. It works by reflecting some of the shock wave backwards which has the effect of lengthening it. The tamper or reflector might be designed to work as the pusher too, although a low density material is best for the pusher but a high density one for the tamper. To maximize efficiency of energy transfer, the density difference between layers should be minimized.

Step 3 - How to build the nuke?

You will need to get the fissile material to the critical mass in order to start the chain reaction, which depends upon the size, shape and purity of the material as well as what surrounds the material. Your weapons-grade uranium will have to be in subcritical configuration.

First, you must arrange the uranium into two hemispherical shapes, separated by about 4 cm. Since it's highly radioactive, the best way do it is to ask the friend owning the small country to let you use one his facilities. You could use a nuclear plant, a steel factory or even a well equipped pharmaceutical installation as a disguise for your plans.

It is not sufficient to pack explosive into a spherical shell around the tamper and detonate it simultaneously at several places because the tamper and plutonium pit will simply squeeze out between the gaps in the detonation front. Instead, the shock wave must be carefully shaped into a perfect sphere centered on the pit and traveling inwards. This is achieved by using a spherical shell of closely fitting and accurately shaped bodies of explosives of different propagation speeds to form explosive lenses.

After a few careful calculations, all you need now is to carefully pack and transport your nuclear bomb to the targeted location. If you happen to be an Al-Qaeda fan, you should try to infiltrate a military facility, for the psychological effect. Watch it, though, they are usually well guarded!

Step 4 - Disguising the bomb and placing it for detonation

The smallest nuclear warhead deployed by the United States was the W54, which was used in the Davy Crockett recoilless rifle; warheads in this weapon weighed about 23 kg and had yields of 0.01 to 0.25 kilotons. This is small in comparison to thermonuclear weapons, but remains a very large explosion with lethal acute radiation effects and potential for substantial fallout. It is generally believed that the W54 may be nearly the smallest possible nuclear weapon, though this may be only smallest by weight or volume, not simply smallest diameter.

The best way to disguise it would be in the form of an ordinary appliance, like a copier, a widescreen TV set, or any other inconspicuous electronic device.

Now, all you have to do is transport it to the selected location and get to a safe distance of a few tens of miles, but not far enough to get out of the range of the remote detonator. That is why a cellphone is strongly recommended for its wide range capabilities.

http://news.softpedia.com/news/How-To-Make-An-Atomic-Bomb-53392.shtml

If anyone asks, I got the name of a U2 album wrong.

norrie rugger

you should have made the U2 album your next search lol
Although i would rather be questioned about the bomb than why i was interested in U2

stevenmu

From what I understand (which admittedly isn't a lot), the tolerances are very very small. While the principle is relatively simple, the engineering of the actual device is still quite difficult. The casing, pusher shell, high explosive 'lenses', and the core itself must be manufactured and shaped to tolerances of tiny fractions of millimeters, and the timing of the explosives needs to be incredibly precise.

I believe that the equipment needed to work with the materials at the level required is still highly controlled internationally and restricted for sale or export, so it takes a lot of resources even to just build the equipment needed to build a bomb.

It is a little frightening though that it really just amounts to an engineering challenge.

laugh

3DataModem

I met a bloke who built one once.

Google "The A Bomb Kid"

amen

the theory is fine but the practice is hard.

in theory its easy to make a plane fly but try building a 747 in your garage

norrie rugger

amen wrote: »

the theory is fine but the practice is hard.

in theory its easy to make a plane fly but try building a 747 in your garage

Ok so you night not be able to build a 747 but you would get something that would fly

Turtwig

norrie rugger wrote: »

Ok so you night not be able to build a 747 but you would get something that would fly

Highly doubt it.

housemap

Yea if you could get your hands on a quantity of plutonium or enriched uranium you wouldn't have too much trouble making a bomb.

Check out the wiki article on the pakistan nuke program , apparently the yanks are very worried about the security of their bombs and materials and consider that it would be where terrorists and fellow travellers would most likely source materials.

They are currently (it is thought) training a special forces unit whose sole purpose would be to enter Pakistan in the event of materials going loose and to recover them.

riffmongous

Semtex would be good too, but it's a bit hard to get, these days.

Getting hold of some plutonium or uranium and building an atomic bomb, no problem, just don't ask me to get a bit of semtex

housemap

Malty_T wrote: »

Highly doubt it.

Wat ?? give me a sheet of A4 and I'll give you something that can fly.

The amount of info on flight online is breathtaking,

Given the will a failure to build a fully functional plane for no more than a few grand and a few months would only be indicative of the mental capacities of the person attempting it and not the difficulty of the task.

norrie rugger

Malty_T wrote: »

Highly doubt it.

Really? you doubt that with tools and materials today that someone would not be able to better the Wright brothers of over 100 years ago?

Turtwig

housemap wrote: »

Malty_T wrote: »

norrie rugger wrote: »

amen wrote: »

the theory is fine but the practice is hard.

in theory its easy to make a plane fly but try building a 747 in your garage

Ok so you night not be able to build a 747 but you would get something that would fly

Highly doubt it.

Wat ?? give me a sheet of A4 and I'll give you something that can fly.

The amount of info on flight online is breathtaking,

Given the will a failure to build a fully functional plane for no more than a few grand and a few months would only be indicative of the mental capacities of the person attempting it and not the difficulty of the task.

Really, I just this dug hole for myself but I must say the paper plane analogy is misleading as it doesn't actually fly, it just "falls with style":p (The latter part about the materials though was spot on.) Anyways here's how such a fabulous brain fart came about. In my haste I misread norrie's comment as something along "It could still serve the role of a 747.. My "highly doubt it" was referring to the fact that building something in your garage would never fly from here to Syndey carrying a shed load of passengers. As to how I got that from his comment I don't know (It's isn't the first I've totally misread others people posts, though normally, I cop it and run a lightning edit.) Anyways, all criticism of the fart were deserved.:)

VNP

Has there been a nuke suicide bomber yet? sounds like in building one in the potting shed you' d be taking on that role. I know a guy who built his own hang glider in the 70s, he broke his pelvis:eek:.