vinnie neutrinos
Posted on 03/29/2004 5:04:19 PM PST by vannrox
A super-powered neutrino generator could in theory be used to instantly destroy nuclear weapons anywhere on the planet, according to a team of Japanese scientists.
If it was ever built, a state could use the device to obliterate the nuclear arsenal of its enemy by firing a beam of neutrinos straight through the Earth. But the generator would need to be more than a hundred times more powerful than any existing particle accelerator and over 1000 kilometres wide.
"It is really quite futuristic," Alfons Weber, a neutrino scientist at Oxford University, UK, told New Scientist. "But the maths and physics seems to be right."
John Cobb, another researcher at Oxford University, cautions: "It might be technically feasible, given massive investment, but there are still unsolved problems."
Ghostly particles
Neutrinos are elementary particles with no electric charge and virtually no mass. They are produced in the nuclear reactions within stars and pass through the Earth in their thousands every day. As they pass through ordinary matter, neutrinos scatter atomic nuclei.
By scattering neutrons in uranium or plutonium, a sufficiently high-powered beam of neutrinos would destabilise a nuclear bomb. According to Hiroyuki Hagura and Toshiya Sanami at Japan's KEK High Energy Accelerator Research Organization and Hirotaka Sugawara at the University of Hawaii this would cause the weapon to "melt down" without triggering the chain reaction needed for it to fully detonate.
But the "muon storage ring" generator needed to propose the neutrino beam would need to be 1000 kilometres wide. It would also require 50 gigaWatts of power to operate - the same as used by the entire UK - and would cost an estimated $100 billion to construct.
Weber says the first stage of a generator might be feasible within 10 to 20 years, but he reckons the main problem is that the neutrino beam produced would be just a few metres wide. This means a target would need to be very precisely located beforehand. He adds that the beam would produce dangerous alpha and neutron radiation in any living thing in its path.
Considering you can get maybe 2 kW of power per square meter from solar collectors, you'd need about 500,000 square meters of solar panels to power this puppy -- and then you could only use it during the 14-day Lunar "day."
How does it stop nuclear weapons in terrorist hands where one does not know where to aim the Neutrino Gun?
If I can neutralize Plutonium, can it also do it to Carbon, or whatever element you tune it to?
I'm not a nuclear physicist, but I'm guessing that neutrinos would be used to accelerate the decay rate of radioactive materials. Stable elements like most carbon might get annoyed, but wouldn't fall apart.
Just kidding about the cleaning fluid, by the way.
Neutrinos are very hard to detect, and they can pass through a lot of ordinary matter without ever reacting with anything. That is the reason they are very hard to detect.
If a neutrino can pass through the entire Earth without being affected in the slightest degree, why would it react with a nuclear bomb?
Since the Earth is being bombarded with lots of neutrinos as a matter of course, for this to work, that would mean that no nuclear bomb has ever worked in the past.
Oh, I don't know; fire ants might just be tougher than nuclear weapons...
Wow, guys, this is straight from "Mad Magazine" in the 1950's! Can somebody track it down?
No kiddin', I remember a "Mad" cartoon of the US and Russia blasting rockets through the earth at each other!
vinnie neutrinos
That was my point.
Let's spend billions of dollars to develop it, then outsource its manufacturing to Pakistan so the radical Muslims can finally get the weapon they've been dreaming of to literally blow up the world.
Thank God we are spending so much money on science. It is really coming in handy now.
My understanding is that it's a question of concentration. For example, one could look at photons. The suns rays are not particularly threatening (ignoring skin cancer), but focus them with a magnifying glass...
So the difference would be between the light "rain" of neutrinos constantly falling on the earth, and the laser-like concentration of a high-density neutrino beam.
"If a neutrino can pass through the entire Earth without being affected in the slightest degree, why would it react with a nuclear bomb?"
Good question. Perhaps it doesn't do significant damage to materials less dense than a plutonium or uranium core. Or perhaps they'd have to focus multiple converging beams on a single spot so the combined concentration of the beams provides the desired effect.
"Now witness the firepower of this fully armed and operational death star!"
In heavier nuclei, the number of neutrons increases to a higher portion of the overall nucleus. But the nucleus as a whole can become unstable, when the number of neutrons is near the edges of what this binding can hold together. So heavy nuclei with the right number of nucleons (in particular) are more likely to break apart. This is the fission radioactivity of e.g uranium-235, and of plutonium.
It happens in smaller nuclei too. But those tend to be either very stable, or to decay so rapidly no appreciable amount of the radioactive versions is seen. A few types with long half lifes but that do decay are present in trace amounts, e.g. carbon 18, with a ten thousand year half life. For comparison, uranium 235 has a half life on the order of 700 million years. Left to itself, that is how slow the breaking apart happens.
In a nuclear bomb, free neutrons are shot into a nucleus to accelerate its breakup, which it turns spits out some additional neutrons, which don't "fit" in either of the smaller daughter nuclei. If this happens rapidly enough it sets off a cascade, the famous chain reaction.
Shooting neutrinos at the nucleus instead, will turn some of the neutrons inside into protons, emitting an electron as well (beta decay radiation). This will drive the resulting material up the table of elements (higher proton number) until it hits an unstable form, then it will split. Thus, repeated, it will tend to accelerate the decay of the nucleus, but without releasing scads of free neutrons to drive a chain reaction.
The chance of any given neutrino interacting with a neutron to cause such a proton-electron split, is tiny. And in typical matter, very little of the area is occupied by the neutrons themselves - the only thing the neutrinos will interact with (essentially). They have no electric charge, so they don't notice the electrical repulsion forces that give ordinary matter its "exclusivity" in space (inability to penetrate each other, etc - that is a solid wall of electric charge hitting another such wall). That is why they pass right through most matter.
The earth is opaque to light, because light is electromagnetic radiation, and it hits the electric field of electrons or protons in ordinary matter, stopping the light. It is largely transparent to neutrinos, because an individual neutrino can pass through a mile of rock with only an infinitessimal chance of actually hitting a neutron anywhere along the way.
Neutrons are small, in other words. Even scads of them in solid matter make a thin net. Neutrinos go through matter containing neutrons rather like water goes through chicken wire - not because the material in the wire can't stop them, but because a fence of the stuff is mostly holes and air, with only a small portion of the area covered by stuff that will stop the water.
But if you turn on a hose high enough, you can be sure you will get the links of the fence wet. Get a powerful enough neutrino source, and you will "dose" some portion of the neutrons along the path of the beam. "But don't solar neutrinos already dose them?" At some rate, sure. And radioactive materials decay naturally. But make a neutrino source many times "brighter" than that - over a small area - and you might measurably speed up the rate of decay.
What may be a bit crazy about the idea (besides the impracticality, on which a bit more below) is that so much energy dumped along a narrow beam is going to set of neutron to hydrogen reactions all along its length. They talk of "increased neutron and alpha radiation". That's a bit of an understatement.
Then there is the impracticality of spending $100 billion to disable one enemy nuke, when one nuke of your own will do it for one ten thousandth of the price. Maybe the idea is the enemy won't know, or won't treat as hostile, a disabling hit that doesn't smash the whole silo with a big mushroom cloud. But there is no obvious reason why this would be so.
People wouldn't want their nukes destroyed by enemy weapons, even if those weapons were fluffy bunnies or secret agents with hairpins. And might react in much the same way to losing them, as they would to counterforce targeted nukes. It is not like there is any great mystery about some practical way to blow up a nuke. But perhaps they expect it would somehow be all different, if the disabler isn't using nukes himself. Maybe, but it seems to be purely speculative.
And if they are going to react the same way as they would to a counterforce attack by any other means, then being able to take out one, exactly located, enemy nuke, is not exactly a new capability or one worthy of a $100 billion price tag. Just bomb the thing.
Now, where it might be nice to have, is if it can be targeted finely enough on a moment's notice to disable enemy nukes that have already "left the station", as it were. Then it might be a kind of final safety against an accidental or rogue launch. But again much of that mission can be done by missile defense, costing considerably less.
Still it is a fun idea to think about. If the numbers had come out a bit differently, it might be important and practical. A nuke neutralizer cannon would be great - if it weren't the size of France.
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