5 ms·

The title alone should give you pause; neutrinos are no easy thing to wrangle. We build giant swimming pools of water underground in the dark to try to catch th

The title alone should give you pause; neutrinos are no easy thing to wrangle. We build giant swimming pools of water underground in the dark to try to catch them. https://what-if.xkcd.com/73/ https://what-if.xkcd.com/73/ "We emphasize that the whole technology is futuristic and thereason should be clear toall the accelerator experts. Actually, even the simplest prototype of our proposal, i.e. theneutrino factory of GeV range needs substantial R & D work. Wealso note that a 1000 TeVmachine requires the accelerator circumference of the order of 1000 km with the magnetsof≃10 Tesla which is totally ridiculous. Only if we can invent a magnet which can reachalmost one order of magnitude higher field than the currentlyavailable magnet, the proposalcan approach the reality. Even if it becomes the reality, thecost of the construction is ofthe order of or more than 100 billion US$. Also we note that thepower required for theoperation of the machine may exceed 50 GW taking the efficiencyinto account. This is abovethe total power of Great Britain. This implies that no singlecountry will be able to affordthe construction of this machine and also the operation timemust be strictly restricted. Webelieve the only way this machine may be built is when all the countries on earth agree todo it by creating an organization which may be called the “World Government” for whichthis device becomes the means of enforcement."

pugworthy 6y ago
It sounds staight out of Star Trek
cshimmin 6y ago
Particle physicist here! Actually it's pretty easy to generate intense neutrino beams. You just have to accelerate protons and smash them into a lead wall. This produces all kinds of particles, including for instance muons. Since muons are charged, you can filter and focus them into a beam using magnets, and then they rapidly decay in flight, producing a beam of neutrinos going in the same direction. As you say, they are quite difficult to detect once produced. This is exactly what the DUNE experiment will be doing. It's a large underground detector in North Dakota that will measure properties of neutrinos produced in a beam at Fermilab near Chicago. The difficulties mentioned in the quote from the article have little to do with neutrinos. 1000 TeV is simply an insanely high energy for any particle beam.
- deftnerd 6y ago
  > Actually it's pretty easy to generate intense neutrino beams. You just have to accelerate protons and smash them into a lead wall. This produces all kinds of particles, including for instance muons. Since muons are charged, you can filter and focus them into a beam using magnets, and then they rapidly decay in flight, producing a beam of neutrinos going in the same direction. That's pretty fascinating. When the protons hit the lead wall, are there any other "messy" particles created that are problematic? Filtering and focusing the muons might be relatively easy to handle, but what about the other kinds of particles that will be created?
  - jjk166 6y ago
    By selecting the energy of the proton beam correctly, you can prevent much besides the muons from being produced. Whatever other particles do show up - if not guided by carefully set up electromagnetic fields - will quickly smash into the walls of the device, generating heat as they scatter and decay. Some of this heat can be used to boil a coolant and regenerate energy, but for the most part it is just an inefficiency. The lead wall and some of the material around it will become radioactive waste as some long lived isotopes are produced, but they could potentially have many years of service life.
- protomyth 6y ago
  Sanford Underground Research Laboratory is in Lead, South Dakota.
  - gpderetta 6y ago
    > Lead I guess it is not a coincidence they are putting a neutrino detector in a place called that way. Am I correct to assume there are old lead mines there? Edit: there are mines, very deep mines, but not Lead mines in fact. And the detector is in one of them.
    - zedpm 6y ago
      Lead is not named for the element lead nor is it pronounced the same. It's pronounced like leader (without the er, of course) and named for a mining term[0]. [0]: https://www.britannica.com/place/Lead-South-Dakota https://www.britannica.com/place/Lead-South-Dakota
mandevil 6y ago
Fortunately, Lederman, Schwartz, and Steinberger won the 1988 Nobel Prize in Physics for figuring out how to build a neutrino beam, which is much easier than detecting them. Basically, slam a proton beam into a few feet of something big and heavy. The big heavy stuff will absorb everything else, and leave just a beam of neutrinos, which don't care if you have miles of armor rather than feet.
ApolloFortyNine 6y ago
>This implies that no singlecountry will be able to affordthe construction of this machine and also the operation timemust be strictly restricted. Meh, $100 billion? The US has spent more than that on it's own defense initiative ($200 billion from the sources I found). [1] And as for the power usage, 1 of the two reactors on the new class of aircraft carriers would provide 125MW (or 700MW of thermal energy, granted I'm not a physicist, but the thermal power is probably what they're after here?) [2], so I don't think it'd be out of the realm of possibilities to either build more reactors for the project, or do a combination of hooking up to existing naval reactors and new reactors to run. If the Cold War was going on, I'd be shocked if this wasn't something the U.S military looked into doing. No one is thrilled with MAD approach, it's more of just no one has found a better way to deal with nuclear weapons. [1] https://en.wikipedia.org/wiki/Strategic_Defense_Initiative https://en.wikipedia.org/wiki/Strategic_Defense_Initiative [2] https://en.wikipedia.org/wiki/A1B_reactor https://en.wikipedia.org/wiki/A1B_reactor
- robocat 6y ago
  More than $100 billion after you have invented 100T magnets is how I read it. So a hella lot more expensive than 100G$.
  - jcun4128 6y ago
    The magnets would be electromagnetic right? Not just a new type of material?
jcun4128 6y ago
Kind of interesting when I was thinking about neutrinos was thinking about communication that can go through the Earth but this article is talking about hitting a target to affect the plutonium hmm.

pugworthy 6y ago

It sounds staight out of Star Trek

cshimmin 6y ago

Particle physicist here! Actually it's pretty easy to generate intense neutrino beams. You just have to accelerate protons and smash them into a lead wall. This produces all kinds of particles, including for instance muons. Since muons are charged, you can filter and focus them into a beam using magnets, and then they rapidly decay in flight, producing a beam of neutrinos going in the same direction. As you say, they are quite difficult to detect once produced. This is exactly what the DUNE experiment will be doing. It's a large underground detector in North Dakota that will measure properties of neutrinos produced in a beam at Fermilab near Chicago. The difficulties mentioned in the quote from the article have little to do with neutrinos. 1000 TeV is simply an insanely high energy for any particle beam.

deftnerd 6y ago
> Actually it's pretty easy to generate intense neutrino beams. You just have to accelerate protons and smash them into a lead wall. This produces all kinds of particles, including for instance muons. Since muons are charged, you can filter and focus them into a beam using magnets, and then they rapidly decay in flight, producing a beam of neutrinos going in the same direction. That's pretty fascinating. When the protons hit the lead wall, are there any other "messy" particles created that are problematic? Filtering and focusing the muons might be relatively easy to handle, but what about the other kinds of particles that will be created?
- jjk166 6y ago
  By selecting the energy of the proton beam correctly, you can prevent much besides the muons from being produced. Whatever other particles do show up - if not guided by carefully set up electromagnetic fields - will quickly smash into the walls of the device, generating heat as they scatter and decay. Some of this heat can be used to boil a coolant and regenerate energy, but for the most part it is just an inefficiency. The lead wall and some of the material around it will become radioactive waste as some long lived isotopes are produced, but they could potentially have many years of service life.
protomyth 6y ago
Sanford Underground Research Laboratory is in Lead, South Dakota.
- gpderetta 6y ago
  > Lead I guess it is not a coincidence they are putting a neutrino detector in a place called that way. Am I correct to assume there are old lead mines there? Edit: there are mines, very deep mines, but not Lead mines in fact. And the detector is in one of them.
  - zedpm 6y ago
    Lead is not named for the element lead nor is it pronounced the same. It's pronounced like leader (without the er, of course) and named for a mining term[0]. [0]: https://www.britannica.com/place/Lead-South-Dakota https://www.britannica.com/place/Lead-South-Dakota

mandevil 6y ago

Fortunately, Lederman, Schwartz, and Steinberger won the 1988 Nobel Prize in Physics for figuring out how to build a neutrino beam, which is much easier than detecting them. Basically, slam a proton beam into a few feet of something big and heavy. The big heavy stuff will absorb everything else, and leave just a beam of neutrinos, which don't care if you have miles of armor rather than feet.

ApolloFortyNine 6y ago

>This implies that no singlecountry will be able to affordthe construction of this machine and also the operation timemust be strictly restricted. Meh, $100 billion? The US has spent more than that on it's own defense initiative ($200 billion from the sources I found). [1] And as for the power usage, 1 of the two reactors on the new class of aircraft carriers would provide 125MW (or 700MW of thermal energy, granted I'm not a physicist, but the thermal power is probably what they're after here?) [2], so I don't think it'd be out of the realm of possibilities to either build more reactors for the project, or do a combination of hooking up to existing naval reactors and new reactors to run. If the Cold War was going on, I'd be shocked if this wasn't something the U.S military looked into doing. No one is thrilled with MAD approach, it's more of just no one has found a better way to deal with nuclear weapons. [1] https://en.wikipedia.org/wiki/Strategic_Defense_Initiative https://en.wikipedia.org/wiki/Strategic_Defense_Initiative [2] https://en.wikipedia.org/wiki/A1B_reactor https://en.wikipedia.org/wiki/A1B_reactor

robocat 6y ago
More than $100 billion after you have invented 100T magnets is how I read it. So a hella lot more expensive than 100G$.
- jcun4128 6y ago
  The magnets would be electromagnetic right? Not just a new type of material?

jcun4128 6y ago

Kind of interesting when I was thinking about neutrinos was thinking about communication that can go through the Earth but this article is talking about hitting a target to affect the plutonium hmm.