Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: tony6789 on 09/02/2006 14:46:11
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If you fused a hand gernade with a nuclerear bomb cuold you get even more disasteruos effects?
- Big T
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No [:)]and the hand granade could prevent the nuclear bomb from detinating if it went off first
Michael
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No i am saying if you added the chemicals from like a dozen gernades into a nuke so they were one would the explasion be even maore desaterous than a regular nuke?
- Big T
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I'm certainly no nuclear physicist and my name is not oppenheimer but I would have thought that even the ingredients from a thousand hand grenades would hardly make any difference at all to the ensuing nuclear reaction....but then that's my purpose here...to consistantly be corrected and educated !
Men are the same as women.... just inside out !!
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I suspect what Mickey was trying to suggest was that nuclear explosions are very carefully shaped, and adding an arbitrary bit of explosive on the side of it could undermine the shape of the explosion.
A nuclear bomb contains a few pieces of fissile material that will do very little at all, surrounded by conventional explosive designed compress all that fissile material into a compact form that would allow it to go critical. If a slight explosion distorts the shape of explosion (implosion) that forces the fissile material together, the form of that fissile material will not be as compact, and it will very possibly not go critical.
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quote:
I suspect what Mickey was trying to suggest was that nuclear explosions are very carefully shaped, and adding an arbitrary bit of explosive on the side of it could undermine the shape of the explosion.
Cheers george, that is exactly what i mean't
Michael
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before you could pull the pins on a thousand grenades,the first 989 grenades would have exploded,there-bye messing up your experiment.
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I am all confused could you simplify it fr me
- Big T
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quote:
Originally posted by tony6789
I am all confused could you simplify it fr me
- Big T
I'm not an expert on nuclear fusion (nor much else), so I'll try and give a layman's eye view.
Uranium 235 (i.e. the type you can use in nuclear bombs – uranium 238 won't work in bombs), or plutonium, can be used in bombs because if an atom of the material is hit by a neutron, it will shatter, and send 3 new neutrons. As you can see, one neutron in, 3 neutrons out, so you can get an ever increasing rate of chain reaction, and while it is doing this, it is generating a lot of energy, that ultimately becomes the basis for your explosion.
The trouble is, the likelihood that a neutron travelling a block of uranium or plutonium will actually hit the nucleus of the atom is very very small, so the greatest likelihood is that the neutrons will just escape out of the uranium/plutonium, and so it simply wont explode.
So what you need to do is have a big enough block of uranium/plutonium to give a very high probability that the neutrons will actually find an atom to hit within the bulk of the material. The minimum size of material you need to have in one block to guarantee that enough neutrons will find enough atoms to hit is known as the critical mass.
In the first atomic bombs, they used a very crude mechanism, where they just had two small pieces of uranium, each below the critical mass, but when brought together, they formed enough uranium to become a critical mass, and start an explosion.
As you try and make bombs that create bigger explosions than this, you need to combine much larger amounts of uranium/plutonium than you can get with just two small pieces or uranium.
As a simple example, lets say you want to bring together a bomb that has almost 4 times the critical mass of uranium. You would need to bring together 4 small blocks of uranium into a single explosive mass. The problem is that even bringing together 2 of these small blocks will cause a small explosion, but would cause the power of the other 2 blocks to be wasted, so you have to make sure that all 4 blocks come together at exactly the same time (within a few microseconds of each other), and so you need explosive charges that with blast these pieces together at exactly the same time.
Even if you only want a smaller explosion, one of the ways to make smaller nuclear explosions is by reducing the critical mass needed before you can start a chain reaction. You do this by increasing the likelihood that a neutron will find another atom to hit, and shatter apart. One of the ways you can do this is by squeezing the uranium block in order to bring the atoms closer together, and thus make it less likely that a neutron will find a path between the atoms where it can escape without hitting an atom. The way you would compress the block of uranium is by packing conventional explosive around it, and when you explode that conventional explosive it will squeeze the uranium into a smaller ball, and so the uranium starts an explosive chain reaction.
The point is, one way or another, you need to use conventional explosive to make a modern nuclear bomb go critical, but that explosive is used to force the uranium or plutonium together. If you think about trying to squeeze a balloon, if you squeeze it on one side more than another, it will simply push the balloon away from you – if you want to squeeze a balloon into a smaller ball, you have to make sure the pressure is equal from all sides. You can think of the explosives trying to squeeze the uranium together as it it was a balloon.
Hope that hasn't confused you even more.
No doubt some nuclear physicists will tell me all the bits I got wrong, but hopefully not wildly wrong.
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but still what if they added gun powder to a nuclear bomb i mean lots of it would the explosion be bigger
- Big T
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quote:
Originally posted by tony6789
but still what if they added gun powder to a nuclear bomb i mean lots of it would the explosion be bigger
- Big T
If by gunpowder, you are referring to what is often now called 'black powder' (i.e. salt petre/sulphur/charcoal) then this is not commonly used these days, it is a very low explosive (i.e. it burns very slowly, and is only explosive if constrained within a container, and it is the bursting of that container that causes an explosion, rather like a pressure cooker that explodes). More commonly, explosives such as TNT, which are high explosives, are used.
Whether the addition of more explosive would increase the power of the explosion depends upon what you do with it. If the explosive were to disrupt the shape of the implosive detonation used to trigger the chain reaction, then it would not only not not increase the power of the explosion, it would reduce the power of the explosion very significantly.
The first nuclear bombs, those dropped on Japan, had an explosive force about equivalent to 15,000 tons (or should that be tonnes – I'm not sure, and it wouldn't make much difference) of TNT. On the other hand, that was an extremely inefficient explosion. It is estimated that of the 60Kg of uranium was used in the bomb, but only 0.7Kg actually contributed to the explosion. Modern devices are no doubt much more efficient.
A B-52 can carry about 31,000Kg of ordinance, which if it was pure TNT (not allowing for the bomb casing, etc.) would only add 0.2% to the amount of effective explosive force of the Hiroshima bomb, that is even if it does not undermine the nuclear explosion.
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But gun powder is used in modern guns today
- Big T
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quote:
Originally posted by tony6789
But gun powder is used in modern guns today
- Big T
OK, that is why I was asking what you meant by gunpowder.
The original gunpowder is what is now known as 'black powder', but this creates a lot of smoke and residue, which made repeated firing difficult because it would obscure the line of sight, and tended to quickly foul up the barrel. In the latter part of the 19th century smokeless gunpowder was developed, which had neither of these problems.
None of these are really high explosives, because if you were to use high explosive in a gun barrel you would simply shatter the gun barrel (which is why you don't use dynamite or plastic explosive or guncotton to propel a bullet of of a gun).
George.
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What if they combined the ingredients of two nukes into one?
- Big T
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My best guess is that what we are told about nuclear bomb making is quite ficticious. If it were true, more countries would have nuclear capabilities. My guess on how nuclear bombs work is this. Element Uuu(111) is synthetically created from Bi and Ni. The channels within its strucutre are large enough to fit protons through. Subsequently, it is utilized to obtain protons. Protons are necessary as they have substantial mass and due to their positive charge they can be propelled at high spees. Then these protons are sent at high speeds into an element such as Helium. When the protons hit the nucleus of the Helium atoms, it produces a chain reaction blowing apart the nuclues' of other helium atoms producing Hydrogen or completely disengrating into protons, neutrons and electrons free of any nuclear bond. The release of energy would be quite extreme...4 atomic mass units * (300,000 km/s)^2 per helium atom.
quote:
Originally posted by another_someone
quote:
Originally posted by tony6789
I am all confused could you simplify it fr me
- Big T
I'm not an expert on nuclear fusion (nor much else), so I'll try and give a layman's eye view.
Uranium 235 (i.e. the type you can use in nuclear bombs – uranium 238 won't work in bombs), or plutonium, can be used in bombs because if an atom of the material is hit by a neutron, it will shatter, and send 3 new neutrons. As you can see, one neutron in, 3 neutrons out, so you can get an ever increasing rate of chain reaction, and while it is doing this, it is generating a lot of energy, that ultimately becomes the basis for your explosion.
The trouble is, the likelihood that a neutron travelling a block of uranium or plutonium will actually hit the nucleus of the atom is very very small, so the greatest likelihood is that the neutrons will just escape out of the uranium/plutonium, and so it simply wont explode.
So what you need to do is have a big enough block of uranium/plutonium to give a very high probability that the neutrons will actually find an atom to hit within the bulk of the material. The minimum size of material you need to have in one block to guarantee that enough neutrons will find enough atoms to hit is known as the critical mass.
In the first atomic bombs, they used a very crude mechanism, where they just had two small pieces of uranium, each below the critical mass, but when brought together, they formed enough uranium to become a critical mass, and start an explosion.
As you try and make bombs that create bigger explosions than this, you need to combine much larger amounts of uranium/plutonium than you can get with just two small pieces or uranium.
As a simple example, lets say you want to bring together a bomb that has almost 4 times the critical mass of uranium. You would need to bring together 4 small blocks of uranium into a single explosive mass. The problem is that even bringing together 2 of these small blocks will cause a small explosion, but would cause the power of the other 2 blocks to be wasted, so you have to make sure that all 4 blocks come together at exactly the same time (within a few microseconds of each other), and so you need explosive charges that with blast these pieces together at exactly the same time.
Even if you only want a smaller explosion, one of the ways to make smaller nuclear explosions is by reducing the critical mass needed before you can start a chain reaction. You do this by increasing the likelihood that a neutron will find another atom to hit, and shatter apart. One of the ways you can do this is by squeezing the uranium block in order to bring the atoms closer together, and thus make it less likely that a neutron will find a path between the atoms where it can escape without hitting an atom. The way you would compress the block of uranium is by packing conventional explosive around it, and when you explode that conventional explosive it will squeeze the uranium into a smaller ball, and so the uranium starts an explosive chain reaction.
The point is, one way or another, you need to use conventional explosive to make a modern nuclear bomb go critical, but that explosive is used to force the uranium or plutonium together. If you think about trying to squeeze a balloon, if you squeeze it on one side more than another, it will simply push the balloon away from you – if you want to squeeze a balloon into a smaller ball, you have to make sure the pressure is equal from all sides. You can think of the explosives trying to squeeze the uranium together as it it was a balloon.
Hope that hasn't confused you even more.
No doubt some nuclear physicists will tell me all the bits I got wrong, but hopefully not wildly wrong.
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Another someone is resonably right and maximillian is talking tripe
There are one or two tricks and important pieces of information that you need to know exactly but the biggest difficulty is obtainig the highly enriched uranium which neeeds a large industrial scale plant. Plutonium is easier to seperate but even that needs some clever chemical engineering an a nuclear reactor ro irradiate the uranium fo a long time to make the plutonium
Learn, create, test and tell
evolution rules in all things
God says so!
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The short answer to your question is no.
To a first approximation, to get "earthy", is that it would be like peeing in the ocean. The ocean is so big that you don't even notice the extra water. A nuclear explosion is so large (a one megaton warhead is the equivalent of one million tons of TNT after all).
To a second approximation, you would probably get even less of an effect, since the nuclear explosion would be probably be hot enough to vaporize the grenades, providing little to no explosive boost at all.
To a third approximation (as mentioned elsewhere), you might end up destroying the bomb with no nuclear explosion. A bomb must have a very precise shape to generate a nuclear explosion. If the grenades disrupt that shape, the nuclear explosion may not occur. You'd at least notice the grenades exploding, however. [;)]
DrDick