What happens to all that debris?

tlb wrote:An X-ray laser beam does not work the same as a microwave oven. The actual result would not be good for the occupants of a pod, but that is mainly because it will blast the pod apart (and its contents); not because it will super-heat water molecules.

ThinksMarkedly wrote:Then we'll be glad the Honorverse uses grasers, not masers.

A cavity of suitable enough material can provide amplification effects for a wave. This happens with radio waves ("wave guides" for example) and in your microwave. In fact, that's why lasers exist in the first place, among other things. Grasers could do that too, but given their extremely short wavelengths, such a cavity would need to be extremely small. Our science today can't make xrasers and grasers. There's also no material known to be reflective to gamma rays.

In the extremely unlikely event that a graser hair-thin beam went through the launch tube without hitting the walls, it would also just hit whatever is at the end of the tube, causing that to vapourise and push plasma towards the occupants on the other side. People would be cooked by the tremendous amount of energy released, vapourised even, but not as an indirect effect.

But that requires a perfect shot.

A graser beam is not hair thin; from War of Honor, chapter 28:

"...So I did exactly what Mister Pirate told me to," Thomas Bachfisch said with an evil grin. "We hove to, opened our personnel locks, and stood by to be boarded. And then, when their boarding shuttles were about five hundred klicks out, we opened the weapons ports and put an eighty-centimeter graser straight through their ship."

Obviously the beam is not the full wide of the graser, instead it has a Gaussian profile (let's guess a quarter of the diameter for the main part of the beam); so about 20 cm for Bachfisch's weapons, which would be small compared to the latest Manticoran weapons for cruisers and SD's (maybe even destroyers). The reflectors are probably based on artificial gravity, which can also provide focusing.

tlb wrote:A graser beam is not hair thin; from War of Honor, chapter 28:

"...So I did exactly what Mister Pirate told me to," Thomas Bachfisch said with an evil grin. "We hove to, opened our personnel locks, and stood by to be boarded. And then, when their boarding shuttles were about five hundred klicks out, we opened the weapons ports and put an eighty-centimeter graser straight through their ship."

Obviously the beam is not the full wide of the graser, instead it has a Gaussian profile (let's guess a quarter of the diameter for the main part of the beam); so about 20 cm for Bachfisch's weapons, which would be small compared to the latest Manticoran weapons for cruisers and SD's (maybe even destroyers). The reflectors are probably based on artificial gravity, which can also provide focusing.

Is there any evidence of the beam being of comparable width to the dish that emitted it? I don't see any reason why an 80cm emitter can't produce a 1mm thick beam. In fact, there's also something to be said about focusing more the wider it is: if you look at our current telescopes, in any wavelength, the bigger the telescope the better they can resolve smaller angles.

Whether a hair thin beam makes sense is another story. If you make it too thin, will it just punch through the entire ship and come out on the other side? Given that both ships are moving, the beam will still slice, but if it's too focused, it might not hit enough matter once the leading edge has come out on the other side.

Though it would help with staying focused to greater distances. Maybe the focus width is configurable, depending on the enemy ship's distance.

tlb wrote:A graser beam is not hair thin; from War of Honor, chapter 28:

"...So I did exactly what Mister Pirate told me to," Thomas Bachfisch said with an evil grin. "We hove to, opened our personnel locks, and stood by to be boarded. And then, when their boarding shuttles were about five hundred klicks out, we opened the weapons ports and put an eighty-centimeter graser straight through their ship."

Obviously the beam is not the full wide of the graser, instead it has a Gaussian profile (let's guess a quarter of the diameter for the main part of the beam); so about 20 cm for Bachfisch's weapons, which would be small compared to the latest Manticoran weapons for cruisers and SD's (maybe even destroyers). The reflectors are probably based on artificial gravity, which can also provide focusing.

ThinksMarkedly wrote:Is there any evidence of the beam being of comparable width to the dish that emitted it? I don't see any reason why an 80cm emitter can't produce a 1mm thick beam. In fact, there's also something to be said about focusing more the wider it is: if you look at our current telescopes, in any wavelength, the bigger the telescope the better they can resolve smaller angles.

Whether a hair thin beam makes sense is another story. If you make it too thin, will it just punch through the entire ship and come out on the other side? Given that both ships are moving, the beam will still slice, but if it's too focused, it might not hit enough matter once the leading edge has come out on the other side.

Though it would help with staying focused to greater distances. Maybe the focus width is configurable, depending on the enemy ship's distance.

Please do not confuse a laser (at whatever frequency) with an antenna or a telescope. Within the limit of the Rayleigh distance, the beam width of a laser is approximately the same as the width at the source and begins to increase linearly for distances much greater. So there is no need for focusing and it would be wasteful to make a beam smaller than whatever is dictated by the aperture. I had an argument like this before and these are the numbers I produced then:
(Spoilers) Future Technological Developments.

tlb wrote:Let's look at the equations for Gaussian beam propagation and see what we can see. For Gaussian beams (where the energy is highest in the center and drops rapidly as you measure to the edge) the beam width follows this equation:
w(z) = w(0) * squareroot(1 + (z/R)**2),
where z is the distance from the source and R is the Rayleigh distance. For distances small compared to R the beam width is about the width at the source (which is some fraction of the size the end of the laser) and for distances much greater than R the beam width increases linearly with distance. The equation for the Rayleigh distance is
R = pi * (w(0)**2 / L),
where L is the wavelength of the emitted radiation. This is a simplification based on the wavelength being much smaller than w(0).
The wavelength of an x-ray is in the vicinity of 0.3 nanometers (exponent of -9) and for gamma rays is in the region of 30 femtometers (exponent of -15). If we try those figures we get distances that are nearly a light minute or more. So we should not worry about getting energy to the target, provided we can actually hit it.

PS. I am having difficulty finding the sizes of the graser aperture for the current classes of ships, although there are passages that indicate that they increase based on ship size; such as LAC, DD, CL, CA and SD. From Honor Among Enemies, chapter 5:

But the undeniably fertile imagination of Hemphill's allies in BuShips had given her Q-ships some advantages the Peeps had never thought of. For one thing, their energy batteries would come as a major surprise to anyone unfortunate enough to enter their range. The Peeps' Q-ships had settled for projectors heavy enough to deal with cruisers and battlecruisers, but Hemphill had taken advantage of a bottleneck in the superdreadnought building schedule. Weapons production had gotten well ahead of hull construction, so Hemphill had convinced the Admiralty to skim off some of the completed lasers and grasers sitting around in storage. Wayfarer had barely half the energy mounts of her Peep counterparts, but the ones she did have were at least three times as powerful. If she ever got close enough to shoot anyone with those massive beams, her target was going to know it had been kissed.

As far as escape pods, isn't the area around the ship likely to be ripe with particles from exploding reactors? I hope pods and reactors are not ejected in close proximity. Also, wouldn't the ejecta from exploding reactors pose an unseen danger as far as raining debris? A silent killer entering atmospheres?

cthia wrote:As far as escape pods, isn't the area around the ship likely to be ripe with particles from exploding reactors? I hope pods and reactors are not ejected in close proximity. Also, wouldn't the ejecta from exploding reactors pose an unseen danger as far as raining debris? A silent killer entering atmospheres?

We know that there is efficient anti-radiation shielding, because that permitted the fission reactors in the new LAC design. But as far as exploding reactors go, I believe that it is only those fission reactors which pose a problem; since exploding a fusion reactor releases compressed plasma (created from low atomic weight material), which cools rapidly after expansion.

cthia wrote:I hope pods and reactors are not ejected in close proximity.

Even ship small enough to support ejecting reactors (basically DDs and some CLs) it would usually be an either/or thing for ejecting reactors or abandoning ship.

You'd eject the reactor if doing so would buy the ship more time, and eject pods if the ship is hopelessly crippled or about to die.

It's be extreme bad luck to have a reactor run away, and have to eject rather than shut down, right in the middle of pods ejecting. But if say 10% of the crew has ejected then ejecting a runaway fusion reactor (even if that kills all the ejected pods on that side of the ship) might be worth it if it lets the ship survive long enough for the majority of the remaining crew to get to their pods and eject. OTOH if more of the crew was already out I'm not sure what the better solution is for the runaway reactor - keeping it in the ship might somewhat reduce the size of the plasma blast but the tradeoff is that there are now irradiated chunks of ship turned into high speed shrapnel and I'm not sure which would be more lethal for ejected pods.


But most ships don't even have the option because their reactors are deeply buried behind armor and have no eject mechanism (because it isn't practical to eject a reactor through half the decks and armor of a CA or larger).

Jonathan_S wrote:OTOH if more of the crew was already out I'm not sure what the better solution is for the runaway reactor - keeping it in the ship might somewhat reduce the size of the plasma blast but the tradeoff is that there are now irradiated chunks of ship turned into high speed shrapnel and I'm not sure which would be more lethal for ejected pods.

Is this correct? Naively I assumed that once the plasma was freed, then any nuclear reaction would stop and so the only irradiated pieces would be from the reactor wall prior to the explosion.

In either case, the main danger to the launched pods would be from the flying chunks (whether irradiated or not). Obviously that depends on whether the ship is being accelerated, as we have discussed before.

tlb wrote:I am having difficulty finding the sizes of the graser aperture for the current classes of ships, although there are passages that indicate that they increase based on ship size; such as LAC, DD, CL, CA and SD.

I have found these remarks by members of the forum:

kzt wrote:My impression is that SD grasers are very large diamter. Like 8 meter. Which on low power rapid fire should be abl to do something.

Theemile wrote:Graser beams are huge... The shrike beam has a diameter of 1.5m. Capital beams start in the 3.5m range and go up to 6.5m or so. I would hardly call a beam the size of my living room, "needle-like".

tlb wrote:

Jonathan_S wrote:OTOH if more of the crew was already out I'm not sure what the better solution is for the runaway reactor - keeping it in the ship might somewhat reduce the size of the plasma blast but the tradeoff is that there are now irradiated chunks of ship turned into high speed shrapnel and I'm not sure which would be more lethal for ejected pods.

Is this correct? Naively I assumed that once the plasma was freed, then any nuclear reaction would stop and so the only irradiated pieces would be from the reactor wall prior to the explosion.

Indeed the plasma will cool rapidly and the nuclear reactions will stop.

The problem is if you couldn't do that or if your reactor was overloading due to damage. In that case, your reactor is not controlled and you may be fusing different elements than you intended to. That could produce a burst of fast neutrons and other radioactive products, which will decay. Those fast neutrons would get absorbed and re-released later, which is a health problem.

But I agree the actual shrapnel is likely to be far more dangerous.

Well, irradiated pieces hitting planets has to pose a problem as well. Grayson certainly don't need any more dangerous metals impacting the planet.

You know, we haven't heard of escape pods communicating with each other. I would imagine lifeboats can. An escape pod should at least be able to pick up the signal from another pod since it's so close. If it has even a very rudimentary antenna. That could help alert S&R of the possibility and locus of any other survivors.