3 ms·

I know nothing about nuclear energy but I immediately thought about the Tokamak. The article said it could be useful for scenarios where penetration of a wall o

by 14 5y ago

I know nothing about nuclear energy but I immediately thought about the Tokamak. The article said it could be useful for scenarios where penetration of a wall of a device would be problematic. I thought I wonder if the Tokamak had the need to be sealed in some way and being able to send a signal inside it wirelessly would help. Maybe they need a completely sealed room but they also need to trigger a switch but no one can be in the room and typical communication can not penetrate it. You just need one bit to make it through to flip that switch from a 1 to a 0. This would be the perfect device. Ya I know that probably has no use for the Tokamak and I can’t think of a scenario where you need a completely sealed device with no holes but still need to send a signal inside. Like in the article they also mentioned submarine communications. You sound smart but surely if they could just do other forms of communication they would have already the US military budget is massive. Currently subs float a device to the surface so they can talk. The article says this slows them down and risks exposing them. Beside the couple mentioned in the article already I’m sure there has to be more use cases someone smarter then your or I can see.

gh02t 5y ago
Neutron transmission is not useful in any of these scenarios. Not in a fusion reactor because a fusion reactor produces a ton of neutrons itself, many orders of magnitude higher than any transmission you'd be able to make so it'd be drowned out (most neutron generators use fusion to produce neutrons too so they're probably also at similar energies to what the reactor makes). Plus the problem with the inside of a tokamak vessel is that it's a super extreme environment and not much can survive in there and like I said in another comment you still have to power your neutron generator. Neutrons are also relatively short ranged and more-or-less isotropic in emission (not able to be focused effectively), meaning you need really high fluence (=dangerous) to transmit more than a few meters. For submarines, water actually attenuates neutrons extremely quickly making it completely useless there. And also let's not forget that neutrons activate materials and make them radioactive for long periods even after you stop with the neutrons. For totally sealed rooms there are better solutions (e.g an acoustic transducer). On top of all this, the physics of neutrons mean this will always be very low bandwidth. None of the applications mentioned in the article are remotely credible, IMO, and this is my area of expertise. Perhaps there is some application where this is the best solution. My point is that at best it's extremely niche; the article makes it out like this is revolutionary but it is definitely not nor is it even particularly interesting. This is not military research with an intended application, this is someone slowly moving a block of plastic back and forth in front of a californium source in a university lab and a press release declaring victory. The actual article published by the scientists in NIM is much more reasonable, but the one linked here is greatly playing up the utility. A fairly reasonable analogy that captures some of the downsides of using neutrons for this is that you could also transmit information by shooting at a metal plate with a pellet gun and having someone listen for the pinging sound. Sure it's possible, but the list of drawbacks is pretty long.

by 14 5y ago

gh02t 5y ago

Neutron transmission is not useful in any of these scenarios. Not in a fusion reactor because a fusion reactor produces a ton of neutrons itself, many orders of magnitude higher than any transmission you'd be able to make so it'd be drowned out (most neutron generators use fusion to produce neutrons too so they're probably also at similar energies to what the reactor makes). Plus the problem with the inside of a tokamak vessel is that it's a super extreme environment and not much can survive in there and like I said in another comment you still have to power your neutron generator. Neutrons are also relatively short ranged and more-or-less isotropic in emission (not able to be focused effectively), meaning you need really high fluence (=dangerous) to transmit more than a few meters. For submarines, water actually attenuates neutrons extremely quickly making it completely useless there. And also let's not forget that neutrons activate materials and make them radioactive for long periods even after you stop with the neutrons. For totally sealed rooms there are better solutions (e.g an acoustic transducer). On top of all this, the physics of neutrons mean this will always be very low bandwidth. None of the applications mentioned in the article are remotely credible, IMO, and this is my area of expertise. Perhaps there is some application where this is the best solution. My point is that at best it's extremely niche; the article makes it out like this is revolutionary but it is definitely not nor is it even particularly interesting. This is not military research with an intended application, this is someone slowly moving a block of plastic back and forth in front of a californium source in a university lab and a press release declaring victory. The actual article published by the scientists in NIM is much more reasonable, but the one linked here is greatly playing up the utility. A fairly reasonable analogy that captures some of the downsides of using neutrons for this is that you could also transmit information by shooting at a metal plate with a pellet gun and having someone listen for the pinging sound. Sure it's possible, but the list of drawbacks is pretty long.