Attacking Darius:

Jonathan_S wrote:My assumption would be that the plasma in the tubes would be below the temperature/pressure levels necessary for fusion. (Because otherwise you've got a distributed fusion reactor running throughout your ship; and YIKES!!)
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No, this is how they start fusion reactors. The use the plasma vent system to move plasma at the temperature and pressure needed for HH to He fusion into the pod, missile or drone reactor. So that 30,000K is missing some zeros, as that requires the conditions of a star’s core.

Jonathan_S wrote:My assumption would be that the plasma in the tubes would be below the temperature/pressure levels necessary for fusion. (Because otherwise you've got a distributed fusion reactor running throughout your ship; and YIKES!!).

kzt wrote:No, this is how they start fusion reactors. The use the plasma vent system to move plasma at the temperature and pressure needed for HH to He fusion into the pod, missile or drone reactor. So that 30,000K is missing some zeros, as that requires the conditions of a star’s core.

I had thought that the plasma in the tubes was the output of the fusion reactor and so already contained enough helium that fusion was inhibited. But the presence of helium might not allow you to start the new missile reactors that KZT mentions; so that is likely not correct. Therefore backing off some on the pressure seems to be most likely.

PS: I was not intending that there would be fusion occurring in the tubes; only that if artificial gravity was sufficient to contain plasma in tubes, then it did not seem a stretch to up the pressure enough to sustain fusion. Possibly that is what they did to create the mini-reactors for the newest generation missiles.

tlb wrote:

Jonathan_S wrote:My assumption would be that the plasma in the tubes would be below the temperature/pressure levels necessary for fusion. (Because otherwise you've got a distributed fusion reactor running throughout your ship; and YIKES!!).

kzt wrote:No, this is how they start fusion reactors. The use the plasma vent system to move plasma at the temperature and pressure needed for HH to He fusion into the pod, missile or drone reactor. So that 30,000K is missing some zeros, as that requires the conditions of a star’s core.

I had thought that the plasma in the tubes was the output of the fusion reactor and so already contained enough helium that fusion was inhibited. But the presence of helium might not allow you to start the new missile reactors that KZT mentions; so that is likely not correct. Therefore backing off some on the pressure seems to be most likely.

PS: I was not intending that there would be fusion occurring in the tubes; only that if artificial gravity was sufficient to contain plasma in tubes, then it did not seem a stretch to up the pressure enough to sustain fusion. Possibly that is what they did to create the mini-reactors for the newest generation missiles.

Reminds me of a turbo system.

tlb wrote:I had thought that the plasma in the tubes was the output of the fusion reactor and so already contained enough helium that fusion was inhibited. But the presence of helium might not allow you to start the new missile reactors that KZT mentions; so that is likely not correct. Therefore backing off some on the pressure seems to be most likely.

PS: I was not intending that there would be fusion occurring in the tubes; only that if artificial gravity was sufficient to contain plasma in tubes, then it did not seem a stretch to up the pressure enough to sustain fusion. Possibly that is what they did to create the mini-reactors for the newest generation missiles.

It's hard to do much with 50 million K gas physically, you have to do it all with magnetic or gravity fields. So this gets very weird as you have these stupidly hot pipes that, if damaged, pretty much instantly destroy the ship.

tlb wrote:I had thought that the plasma in the tubes was the output of the fusion reactor and so already contained enough helium that fusion was inhibited. But the presence of helium might not allow you to start the new missile reactors that KZT mentions; so that is likely not correct. Therefore backing off some on the pressure seems to be most likely.

PS: I was not intending that there would be fusion occurring in the tubes; only that if artificial gravity was sufficient to contain plasma in tubes, then it did not seem a stretch to up the pressure enough to sustain fusion. Possibly that is what they did to create the mini-reactors for the newest generation missiles.

kzt wrote:It's hard to do much with 50 million K gas physically, you have to do it all with magnetic or gravity fields. So this gets very weird as you have these stupidly hot pipes that, if damaged, pretty much instantly destroy the ship.

As I wrote in the earlier post (see below), there have to be safety devices to limit damage that do not get mentioned. We have seen ships destroyed by malfunctioning reactors, but by not damage to the plasma pipes. A shutoff that occurred fast enough would fry a compartment, without destroying the ship; but we have not seen mention of even that. I guess there might be some things that simply have to be glossed over; because to try to explain them would take too long and might even be impossible.

The only possibility that occurs to me is that these pipes are outside of the main hull of the ship, so that they vent into space when ruptured. However they cannot be directly exposed to space, because radiant heating means they must be glowing like the surface of the sun.

So basically, I do not know; it is simply the magic of future technology.

There are at least two steps in there that we do not understand; because it involves millennia in the future technology, that is akin to magic for us.

First is how the plasma is confined to the tubes. We can only speculate that it uses the artificial gravity generators in repulsion or pressor beams (that also seem magical). We expect that most of those tubes only contain plasma on demand, with automatic shutoff in case of rupture. Note that the method of confinement probably will not stop radiative heating of those tubes (another source of waste heat).

Second is how that plasma is converted into what we would consider usable energy, such as electricity. We expect that they have something better than magneto-hydrodynamics (or at least a very much improved version of MHD).

cthia wrote:Unless everyone is positing that the fusion thrusters have their own built-in reactor.

I don't think "reactor" is really the right word. Gravity pinch enough to trigger fusion, but not contained.

ThinksMarkedly wrote:At a minimum it would be incredibly less efficient. The oxygen atoms won't participate in the fusion reaction at the energy levels required for fusing hydrogen, deuterium or helium-3, but will absorb energy, both created by that fusion and by the means by which the energy levels of the reactants is brought up. We don't know how a gravity reactor works, but in a plasma reactor like a tokamak, you inject energy into the system by huge electromagnets so the protons accelerate around the torus. If you have these huge blobs with 16x the mass of a proton in the way, they will absorb energy too. And they may have different trajectories than the hydrogen and helium nuclei, which means they could impact the walls of the reactor.

But the Honorverse has gravity pinch fusion, it can be done without confinement. Yes, the oxygen would absorb some of the energy but I don't think that would be a problem.

In one of the books depicting the early Manticore, didn't a pair of heros get one shot from their spinal laser when using a damaged fusion pipe, which then destroyed the enemy ship and theirs as well?

tlb wrote:

tlb wrote:I had thought that the plasma in the tubes was the output of the fusion reactor and so already contained enough helium that fusion was inhibited. But the presence of helium might not allow you to start the new missile reactors that KZT mentions; so that is likely not correct. Therefore backing off some on the pressure seems to be most likely.

PS: I was not intending that there would be fusion occurring in the tubes; only that if artificial gravity was sufficient to contain plasma in tubes, then it did not seem a stretch to up the pressure enough to sustain fusion. Possibly that is what they did to create the mini-reactors for the newest generation missiles.

kzt wrote:It's hard to do much with 50 million K gas physically, you have to do it all with magnetic or gravity fields. So this gets very weird as you have these stupidly hot pipes that, if damaged, pretty much instantly destroy the ship.

As I wrote in the earlier post (see below), there have to be safety devices to limit damage that do not get mentioned. We have seen ships destroyed by malfunctioning reactors, but by not damage to the plasma pipes. A shutoff that occurred fast enough would fry a compartment, without destroying the ship; but we have not seen mention of even that. I guess there might be some things that simply have to be glossed over; because to try to explain them would take too long and might even be impossible.

The only possibility that occurs to me is that these pipes are outside of the main hull of the ship, so that they vent into space when ruptured. However they cannot be directly exposed to space, because radiant heating means they must be glowing like the surface of the sun.

So basically, I do not know; it is simply the magic of future technology.

There are at least two steps in there that we do not understand; because it involves millennia in the future technology, that is akin to magic for us.

First is how the plasma is confined to the tubes. We can only speculate that it uses the artificial gravity generators in repulsion or pressor beams (that also seem magical). We expect that most of those tubes only contain plasma on demand, with automatic shutoff in case of rupture. Note that the method of confinement probably will not stop radiative heating of those tubes (another source of waste heat).

Second is how that plasma is converted into what we would consider usable energy, such as electricity. We expect that they have something better than magneto-hydrodynamics (or at least a very much improved version of MHD).

For the whole Plasma and reactor set o questions with containment and not self immolating every time there is damage, I think the work you are looking for is magic.

Theemile wrote:

cthia wrote:Feed the reactor which is located in the bowels of the ship with water to produce the hydrogen? Then that hydrogen has to travel in a vein thru the ship back out to the thrusters.

Unless everyone is positing that the fusion thrusters have their own built-in reactor.

Cthia, the whole ship is plumbed with Plasma conduits - it's how Honorverse ships transfer power. The capacitors are Plasma Capacitors. Each weapon, drive system, sidewall generator, etc, etc is run off live Plasma.

It came to me about 3 years ago, the plasma system is analogous to Late 19th century steam systems. A ship's screws are turned by steam, the turrets are turned by steam, the guns are elevated by steam. Steam lines are plumbed all over the ship. The steam pressure from the boilers isn't enough on their own so there are steam accumulators (ie capacitors) all over the ship to add more pressure where it is needed.

So hydrogen storage tanks are no biggie, because Hydrogen/Helium plasma at >30,000K is plumbed all over the ship, and every capacitor (one at every weapons system, in every missile, and spread over the ship to add redundancy and power the wedge) is full of live hydrogen/Helium plasma.

Thanks for reminding me of the magic elves of plasma conduits running all over the ship, and their magic cousins the plasma capacitors.

(And thanks-a-million for your steam analogy!)

I understand everyone's sentiment, that in light of being able to safely handle these magic elves, then handling the hydrogen storage tanks that are used in various locations around the ship should be just as easy. I get it. I just can't swallow it.

Of course, the system probably can be made safe when it is operating normally. But when a monkey wrench is thrown into the mix, like those monkey wrenches described as laserheads, that is when I question why the whole thing doesn't easily go boom. But if there are laserheads, you say, then there is a much bigger problem.

But my point is that even the slightest love tap to the most survivable of all ships, the SD, should cause massive destruction from a serious of chain reactions.

For instance, a single hit from a laserhead should destroy at least one vein of plasma conduits. Hot plasma eating through the ship like acid should be the start of something big. Oxygen is always around. Humans need it.

However, I always convince myself that many of the dangers can be solved, not by handwavium, but by the unique element that all of the HV seems to tap into. Gravity.

I can't imagine what could be used to design plasma conduits except pipes of highly controlled gravity. Gravity conduits. Why not? The reactor uses gravity containment. When there are craftsmen in the HV who are such masters of gravity, then all things are possible.

About that gravity. When I consider the myriad number of applications of gravity in the HV, it makes me wonder why certain other things aren't intuitively possible. And even why some things are done the way they are when that obvious mastery of gravity could have solved the problem even better.

BTW, gravity is one reason I think the LDs will be so formidable, because they will showcase the use of gravity in ways that were unthought of. The Spiders already have a more intimate relationship with gravity.

It makes sense that the fuel for the thrusters should be kept near the skin of the ship. That even supports storyline when it says that some ship is leaking atmosphere. I always imagined that atmosphere to be composed of oxygen only. But it is probably a mixture of oxygen, hydrogen and plasma!

Incidentally, the environmental systems must be prepared to pump oxygen throughout the entire ship on a moment's notice. Which means there are also veins of oxygen running all over the ship as well. All of the recipes of disaster are present on every ship. I like to cook. I know what a bad recipe looks like. LOL

Anyway, fuel for the thrusters located near the thrusters on the hull is much safer. An explosion near the hull of the ship is far less dangerous to the ship as a whole. And any long fuse that it may ignite could be instantly shut off by some kind of "gravity valve."