4 ms·

My reading of the paper shows they already factored that into the equation. So at the target, in the 1m² cross-section, 1,000 W of energy is being delivered. It

My reading of the paper shows they already factored that into the equation. So at the target, in the 1m² cross-section, 1,000 W of energy is being delivered. It takes about 50,000,000,000 W at the beam generator to achieve that.

3pt14159 6y ago
If it's just 50 gigawatts it is potentially viable, considering the stakes of nuclear warfare. The precise locations of most stationary nuclear weapons systems are already known, though this would run into some trouble finding nukes on submarines unless they were detected by submerged drones or subullites. I'd look into it.
- CSSer 6y ago
  > most Sounds really perilous. If even one is missed isn’t its risk of usage now astronomically higher?
  - 3pt14159 6y ago
    Well I don't think anyone in charge is really happy about how nuclear weapons are handled these days, but generally speaking I'd say that most people don't want to use them, but they're forced into over-worrying about attack vectors because that's the nature of MAD. Even so, there are so many ways of doing so much damage to an adversary right now I doubt if a major nuclear power would actually deploy[0] offensive neutrino weapons outside of an actual war. [0] There is a difference between use and deploy in military terminology.
jessriedel 6y ago
Which part of the paper? I don't know why they would quote power per unit area for a beam that is clearly depositing it proportional to volume. What is the assumed depth?
- function_seven 6y ago
  The assumed depth is the diameter of Earth. That's where the 10^-7 figure comes in. Look at eq. (1). It's dividing the initial energy (1,000 TeV, or 10^15) by the diameter of Earth (10^-7) The beam energy of 1000TeV is chosen to "have approximately single interaction before the neutrino beam hits the bomb". The mechanism is for a neutrino to interact with the Earth a few meters before the bomb, creating a hadron shower that does the real work. If you look at the equations, they're sub-scripting "E" with "dep", meaning deposited. The figure is arrived at after accounting for the 1/10^7 probability that a given neutrino in the beam actually interacts in the right zone of soil. > The range of the neutrino is 10^7 meters and the effective neutrino interaction is restricted within a few meters away from the bomb because of the interaction range of the hadrons. Which I'm reading as: "we're going to lose the vast majority of this energy in the Earth itself, so we need to choose an initial power level so that, by the time the beam is interacting with the dirt just under the bomb, it's delivering ≈ 1kW of power."
  - jessriedel 6y ago
    Thanks much

3pt14159 6y ago

If it's just 50 gigawatts it is potentially viable, considering the stakes of nuclear warfare. The precise locations of most stationary nuclear weapons systems are already known, though this would run into some trouble finding nukes on submarines unless they were detected by submerged drones or subullites. I'd look into it.

CSSer 6y ago
> most Sounds really perilous. If even one is missed isn’t its risk of usage now astronomically higher?
- 3pt14159 6y ago
  Well I don't think anyone in charge is really happy about how nuclear weapons are handled these days, but generally speaking I'd say that most people don't want to use them, but they're forced into over-worrying about attack vectors because that's the nature of MAD. Even so, there are so many ways of doing so much damage to an adversary right now I doubt if a major nuclear power would actually deploy[0] offensive neutrino weapons outside of an actual war. [0] There is a difference between use and deploy in military terminology.

jessriedel 6y ago

Which part of the paper? I don't know why they would quote power per unit area for a beam that is clearly depositing it proportional to volume. What is the assumed depth?

function_seven 6y ago
The assumed depth is the diameter of Earth. That's where the 10^-7 figure comes in. Look at eq. (1). It's dividing the initial energy (1,000 TeV, or 10^15) by the diameter of Earth (10^-7) The beam energy of 1000TeV is chosen to "have approximately single interaction before the neutrino beam hits the bomb". The mechanism is for a neutrino to interact with the Earth a few meters before the bomb, creating a hadron shower that does the real work. If you look at the equations, they're sub-scripting "E" with "dep", meaning deposited. The figure is arrived at after accounting for the 1/10^7 probability that a given neutrino in the beam actually interacts in the right zone of soil. > The range of the neutrino is 10^7 meters and the effective neutrino interaction is restricted within a few meters away from the bomb because of the interaction range of the hadrons. Which I'm reading as: "we're going to lose the vast majority of this energy in the Earth itself, so we need to choose an initial power level so that, by the time the beam is interacting with the dirt just under the bomb, it's delivering ≈ 1kW of power."
- jessriedel 6y ago
  Thanks much