Can you "Overload" a Laserwarhead?

Sorry, but you got this one wrong as well: explosions in water are more destructive because water is 1000x the density of air, and transmits shocks proportionately better. Since the speed of the shock is also higher [although by a lower factor], energy is transmitted away from the point of explosion faster, so any change in confinement time doesn't increase the energy in the shock - in fact, the mechanism you describe would _reduce_ it by diverting some of the explosion energy into the latent heat of vapourisation.

Relax wrote:< snip >

Explosions in water are vastly more destructive why? Because they have a mass able to HOLD the wave front which creates a longer TIME, allowing greater heating, allowing greater evaporation, equaling far more matter being converted into a larger VOLUME which makes the secondary shock wave much greater. In space, none of these factors are true.

Louis R wrote:Sorry, but you got this one wrong as well: explosions in water are more destructive because water is 1000x the density of air, and transmits shocks proportionately better. Since the speed of the shock is also higher [although by a lower factor], energy is transmitted away from the point of explosion faster, so any change in confinement time doesn't increase the energy in the shock - in fact, the mechanism you describe would _reduce_ it by diverting some of the explosion energy into the latent heat of vapourisation.

Relax wrote:< snip >

Explosions in water are vastly more destructive why? Because they have a mass able to HOLD the wave front which creates a longer TIME, allowing greater heating, allowing greater evaporation, equaling far more matter being converted into a larger VOLUME which makes the secondary shock wave much greater. In space, none of these factors are true.

Seems you are having a senior moment as well. Destructive power is a time derivative against structures. Momentum based. Density is nothing but a scalar. Shock wave based on the speed of sound in water is immaterial as a cause for destruction.

In fact:

If we went with your theory, the speed of sound in a dense material like steel, etc is far higher than that of air or water... Like that of a pressure vessel... Beyond pointless when talking about reaction at or near the speed of light.

Shock waves based on the speed of sound in a material or fluid is of secondary consideration regarding destruction. Get secondary effects based on harmonic frequencies. Completely useless when using nukes with time derivatives in nanoseconds... Now if you wish to talk about shock wave FATIGUE, then yes, speed of sound in a material is very important.

Seems you completely missed the last sentence you copied...

Louis R wrote:Sorry, but you got this one wrong as well: explosions in water are more destructive because water is 1000x the density of air, and transmits shocks proportionately better. Since the speed of the shock is also higher [although by a lower factor], energy is transmitted away from the point of explosion faster, so any change in confinement time doesn't increase the energy in the shock - in fact, the mechanism you describe would _reduce_ it by diverting some of the explosion energy into the latent heat of vapourisation.

I thought the key thing was that water is barely compressible. The shockwave in air would seem to "waste" energy compressing the air (and thereby creating heat).

Relax wrote:PS> One of the main reasons for the magnetic retention today, is to keep the PLASMA OFFFFFFFFFFFFFF the walls of the reactor vessel. If this was not done, it would MELT the reactor vessel... OOPPSSIIIEEESSSS.

IIRC, while the purpose of the magnetic field retention is to keep the plasma off the walls of the reactor vessel, its not to keep melting the walls of the reactor vessel. Instead it's to keep the walls of the reactor vessel from cooling the plasma.

I read somewhere in a science magazine where one of the scientists on the magnetic confinement fusion research project being covered was quoted (as best I can remember) that although the temperature of the plasma being contained was in the tens of millions of degrees, because the mass and density of the plasma was so low, that 1) a cup of hot coffee had more total energy than the plasma being contained and 2) you could in effect cool the plasma down to near room temperature if you could stick your finger into it.

It's similar to the difference between the sun's photosphere (the light radiating surface), chromosphere (the lower atmosphere of the sun--visible during total eclipses), and corona (the upper atmosphere of the sun--visible during total eclipses). While the temperature of the sun's corona is measured in the millions of degrees, the temperature of the sun's chromoshpere and photosphere is measured in thousands of degrees. But the sun's photosphere is far more massive and denser than its chromosphere and corona, so the amount of energy in the photosphere dwarfs the total amount of energy in the chromosphere and corona combined, even though the corona is many times higher in temperature--the chromosphere is slightly cooler than the photosphere.

Jonathan_S wrote:

Louis R wrote:Sorry, but you got this one wrong as well: explosions in water are more destructive because water is 1000x the density of air, and transmits shocks proportionately better. Since the speed of the shock is also higher [although by a lower factor], energy is transmitted away from the point of explosion faster, so any change in confinement time doesn't increase the energy in the shock - in fact, the mechanism you describe would _reduce_ it by diverting some of the explosion energy into the latent heat of vapourisation.

I thought the key thing was that water is barely compressible. The shockwave in air would seem to "waste" energy compressing the air (and thereby creating heat).

While you are discussing this, you are missing a key answer to the original poster's question - as we all know, water is 2/3rd Hydrogen. In any of those water borne or under water explosions did a significant amount of hydrogen fuse and boost the reaction?

The answer is no - the water was outside the nuclear pit and the hydrogen did not fuse and boost the reaction in an appreciable way.

In a similar way, a tank of Hydrogen or Lithium would not boost the nuke's warhead. That is not to say that some individual atoms or millions of individual atoms, for that matter, absorbed neutrons or alphas and split, but no large scale, self sustaining reaction would occur under those conditions

I'm inclined to doubt it, since you completely missed the point I was making. It's the difference in density that matters for energy transmission. One reason for that was summarized nicely by Jonathan in his post.

Relax wrote:

Louis R wrote:Sorry, but you got this one wrong as well: explosions in water are more destructive because water is 1000x the density of air, and transmits shocks proportionately better. Since the speed of the shock is also higher [although by a lower factor], energy is transmitted away from the point of explosion faster, so any change in confinement time doesn't increase the energy in the shock - in fact, the mechanism you describe would _reduce_ it by diverting some of the explosion energy into the latent heat of vapourisation.



Seems you are having a senior moment as well. Destructive power is a time derivative against structures. Momentum based. Density is nothing but a scalar. Shock wave based on the speed of sound in water is immaterial as a cause for destruction.

In fact:

If we went with your theory, the speed of sound in a dense material like steel, etc is far higher than that of air or water... Like that of a pressure vessel... Beyond pointless when talking about reaction at or near the speed of light.

Shock waves based on the speed of sound in a material or fluid is of secondary consideration regarding destruction. Get secondary effects based on harmonic frequencies. Completely useless when using nukes with time derivatives in nanoseconds... Now if you wish to talk about shock wave FATIGUE, then yes, speed of sound in a material is very important.

Seems you completely missed the last sentence you copied...

kzt wrote:

Loren Pechtel wrote:There's also the bomb, I forget which one, where they used U-238 for the casing. Oops--the neutron bombardment from the exploding fusion device caused the case to fission and greatly upped the yield.

Lots of bombs use a depleted uranium radiation case. It's got a lot of useful properties including adding significantly to the yield. It's not light so it isn't used everywhere Iirc.

Yeah, now we know it adds to the yield. The first time we didn't--and got a much bigger boom than expected. Same as now we know Lithium-7 adds to the boom but the first time it was a surprise.

Theemile wrote:While you are discussing this, you are missing a key answer to the original poster's question - as we all know, water is 2/3rd Hydrogen. In any of those water borne or under water explosions did a significant amount of hydrogen fuse and boost the reaction?

The answer is no - the water was outside the nuclear pit and the hydrogen did not fuse and boost the reaction in an appreciable way.

In a similar way, a tank of Hydrogen or Lithium would not boost the nuke's warhead. That is not to say that some individual atoms or millions of individual atoms, for that matter, absorbed neutrons or alphas and split, but no large scale, self sustaining reaction would occur under those conditions

Ordinary water doesn't increase the boom because it's almost all plain hydrogen, not deuterium or tritium. Only the latter add to the boom.

Now, if you used heavy water or doubly heavy water it would add to the boom.

Loren Pechtel wrote:

Theemile wrote:While you are discussing this, you are missing a key answer to the original poster's question - as we all know, water is 2/3rd Hydrogen. In any of those water borne or under water explosions did a significant amount of hydrogen fuse and boost the reaction?

The answer is no - the water was outside the nuclear pit and the hydrogen did not fuse and boost the reaction in an appreciable way.

In a similar way, a tank of Hydrogen or Lithium would not boost the nuke's warhead. That is not to say that some individual atoms or millions of individual atoms, for that matter, absorbed neutrons or alphas and split, but no large scale, self sustaining reaction would occur under those conditions

Ordinary water doesn't increase the boom because it's almost all plain hydrogen, not deuterium or tritium. Only the latter add to the boom.

Now, if you used heavy water or doubly heavy water it would add to the boom.

No… it wouldn’t.

One of the first emisisons of the nuclear event (but not the first) is a neutron wave, and water is a neutron absorber – or more importantly – the hydrogen in it is. The neutron absorption has the effect of turning said hydrogen into deuterium and tritium. (And all water contains a small fraction of deuterium and tritium in its natural state.

The heavy Hydrogen isotopes add to a nuclear explosion when injected into an atomic pit and the pressures created in the pit cause them to fuse. Depending on the amount injected and timing – this either enhances the atomic explosion by the injection of more spare neutrons into the fissile mass (Uranium or Plutonium) increasing the reaction, or creates a second, fusion explosion when the force of the (nearby) fission explosion compresses the deuterium and tritium.

The Deuterium and Tritium in the water is outside the nuclear events and will never achieve the temperatures and pressures necessary to fuse. AS I said upthread, timing and position in a nuclear device are, and have to be, insanely accurate.

Theemile wrote:No… it wouldn’t.

One of the first emisisons of the nuclear event (but not the first) is a neutron wave, and water is a neutron absorber – or more importantly – the hydrogen in it is. The neutron absorption has the effect of turning said hydrogen into deuterium and tritium. (And all water contains a small fraction of deuterium and tritium in its natural state.

The heavy Hydrogen isotopes add to a nuclear explosion when injected into an atomic pit and the pressures created in the pit cause them to fuse. Depending on the amount injected and timing – this either enhances the atomic explosion by the injection of more spare neutrons into the fissile mass (Uranium or Plutonium) increasing the reaction, or creates a second, fusion explosion when the force of the (nearby) fission explosion compresses the deuterium and tritium.

The Deuterium and Tritium in the water is outside the nuclear events and will never achieve the temperatures and pressures necessary to fuse. AS I said upthread, timing and position in a nuclear device are, and have to be, insanely accurate.

You seem to be talking about a boosted fission design where some fusion fuel is injected into the pit of the fission bomb. But that's still the primary for a thermonuclear bomb. The design that, as far as I know, all current thermonuclear bombs uses is the Teller–Ulam configuration where there's a secondary, with the fusion fuel sitting off to the side of the primary boosted fission core. See https://en.wikipedia.org/wiki/Thermonuclear_weapon

The radiation from the explosion of the primary interacts with the material wrapped around the secondary's fusion fuel to initiate the larger secondary fusion explosion.

That same radiation would be slamming into the surrounding water; however I think without the special wrapping material it won't undergo the conversion necessary to trigger any appreciable amount of extra fusion.

So ultimately I think you're right, detonating a fusion bomb underwater isn't going to get any noticeable extra fusion. But it's not because the water isn't inside the primary core; it's because it's not wrapped in the materials necessary for the secondary stage's fusion material to get ignited by the radiation wave from the primary core's detonation.