Terran Nuclear Tech (split from Terran Q&A)

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Siber
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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Siber »

I get ~50m diameter at 50km with 0.057 beam angle.
Right, I think I got crossed up and thought you were proposing that it was dangerous when the beam was dispersed over a 50km wide area, instead of being detonated at 50km. This comes from the idea that I recall being a starting point but I think we've wandered from, that a cassaba howitzer based firing chamber was a reasonable competitor weapon. If you can get your bombs up within 50km then yes it's probably an effective blast, but as I noted in my last post the combatants apparently already use shaped blasts to extend the kill range of their torpedoes, so it's not a very special trick.

However, in my experience divergence angle in these kinds of contexts is measured as angle from the center of the cone to the outside, not angle from far sides of the cone. That would make this a ~50 meter radius, not diameter. I was not able to find a source for the 0.057 beam divergence CHs that was perfectly explicit on this distinction, so I did my math on what I understand to be the default. So all other things being equal you should be getting intensities four times higher than I am.

However, 314000000m^2 is the area of a 10km radius circle, not a 50km or 25km one.

With a 50km radius area of effect, other assumptions permitted, I end up with the surface of the tempest absorbing a total of 17 points of damage, not 429.
112500m2*1131.53MJ
127237500MJ of energy delivered to the tempest on a top down blast at 50000km
It hits with 15.9 times the energy at 50000km then the Terran GWS.
Perhaps, but you already did the math to what damage is done per square meter, and it's not that impressive. If their shields are any good at deflecting plasma, and the armor any more significantly sophisticated than steel, I wouldn't expect this to be a big deal. This is exacerbated if the impact gets spread out at all along the time axis by the trip, which I expect it might be.

Since we don't know the actual operating principles of their shields and the weapons they are built to repel(I suspect both depend on magnetics that aren't actually possible in reality) then we can't say for certain if this kind of broad slap actually has the same effect as a focused impact.

It's also worth considering that the most optimistic number I was able to find on Atomic Rockets was a jet velocity of 10,000km/s, with most figures being much lower. At the ranges under consideration that gives five seconds(or more, in less optimistic numbers) for the plasma to radiate energy and do other interesting things, as well as time for the target to react with turning and/or burning.
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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

You know I have no idea how I managed to do that... I even ran numbers twice to make sure... :?: :roll:

My understanding.
Beam angle is the total angle measured.
Beam deviation is half the angle taken from the vertical.

I have found divergence being used to mean both but SDI paper states beam angle and then beam divergence so meh.

25000m radius circle(25km) which is 50km has an area of 1.96E9 m2
1960000000
314000000
~6.2 greater area.

At 50000km it will take out shields on pure energy alone(68 damage) which is greater then point blank shot of any of the Combatants plasma weapons.
Actual hull damage is another thing entirely... It will still do damage and still pump in a ton of heat(take out a modern day tank for example) I will assume advanced armour likely can stop most of the effects and only sensors and other stuff would be destroyed since they are soft targets.

At 50000km its going to take down the shields pump in heat and take out sensors and damage turrets to some degree but I am going to assume the ships armour will hold.

All my numbers are applicable for 20000km range not 50000km
Its still respectable weapon compared to the other combatants but not nearly as effective range wise.

You can't use antimatter for a shaped charge with the same degree of cohesion, atom formation by neutrons after an antimatter explosion will dirty your propellant rendering any produced beam irregular. That said Umiak/Loroi do have "carrier waves" and if they generated one for it to travel down then it could be vastly more effective then a Casaba then ship based weapons and be instant kills.

I did however discover something interesting, 5.7295779513082E-7 is the current reached deviation on a particle beam.
Particle beam advances are actually being made rapidly due to research and development of hydrogen injectors for fusion chambers and not weapons research. However due to advances made in collimation of particle beams the USA started this year a new particle weapon development program as its been deemed viable with current technology.

Minimum hydrogen beam deviation is
0.0000030939720937064
so
A particle weapon can have inverse divergence, it actually condenses as it moves if its cooled during focusing. Wouldn't work for a Casaba Howitzer but particle weapons don't need a carrier wave to travel long distances in Outsider. It makes complete sense, cool gasses condense when you think about it but its rather cool(no pun intended) yet very simple idea.
Siber wrote:
I get ~50m diameter at 50km with 0.057 beam angle.
Right, I think I got crossed up and thought you were proposing that it was dangerous when the beam was dispersed over a 50km wide area, instead of being detonated at 50km. This comes from the idea that I recall being a starting point but I think we've wandered from, that a cassaba howitzer based firing chamber was a reasonable competitor weapon. If you can get your bombs up within 50km then yes it's probably an effective blast, but as I noted in my last post the combatants apparently already use shaped blasts to extend the kill range of their torpedoes, so it's not a very special trick.

However, in my experience divergence angle in these kinds of contexts is measured as angle from the center of the cone to the outside, not angle from far sides of the cone. That would make this a ~50 meter radius, not diameter. I was not able to find a source for the 0.057 beam divergence CHs that was perfectly explicit on this distinction, so I did my math on what I understand to be the default. So all other things being equal you should be getting intensities four times higher than I am.

However, 314000000m^2 is the area of a 10km radius circle, not a 50km or 25km one.

With a 50km radius area of effect, other assumptions permitted, I end up with the surface of the tempest absorbing a total of 17 points of damage, not 429.

Hydrogen is very penetrating and their is no physical way to stop it besides more mass, a modern day tank at 50000km even with the correct numbers would still have the crew cooked.

Yes shields can stop it, but insider states that even if plasma is defected the shields overload due to the energy level of the hit.
Its still delivering more energy at 50000km with the correct numbers against shields then point blank plasma shots.
112500m2*1131.53MJ
127237500MJ of energy delivered to the tempest on a top down blast at 50000km
It hits with 15.9 times the energy at 50000km then the Terran GWS.
Perhaps, but you already did the math to what damage is done per square meter, and it's not that impressive. If their shields are any good at deflecting plasma, and the armor any more significantly sophisticated than steel, I wouldn't expect this to be a big deal. This is exacerbated if the impact gets spread out at all along the time axis by the trip, which I expect it might be.

Since we don't know the actual operating principles of their shields and the weapons they are built to repel(I suspect both depend on magnetics that aren't actually possible in reality) then we can't say for certain if this kind of broad slap actually has the same effect as a focused impact.

It's also worth considering that the most optimistic number I was able to find on Atomic Rockets was a jet velocity of 10,000km/s, with most figures being much lower. At the ranges under consideration that gives five seconds(or more, in less optimistic numbers) for the plasma to radiate energy and do other interesting things, as well as time for the target to react with turning and/or burning.
Last edited by MBehave on Thu Jun 13, 2019 2:26 pm, edited 1 time in total.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

Casaba Howitzer has almost no beam divergence.
A secondary laser is used as the waveguide instead of trying to do it all with magnetic fields.

Yep its a real thing

https://www.nasa.gov/directorates/space ... /PROCSIMA/

This also makes Arioch "waveguide" technology actually real.
So thats actually really awesome.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Arioch »

PROCSIMA is not a Casaba howitzer.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

Your right, its only half of a PROCSIMA system(ok its not PROCSIMA at all but the laser waveguide is valid), the other half is the laser array circling the output aperture.
Image
Arioch wrote:PROCSIMA is not a Casaba howitzer.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Arioch »

The PROCSIMA concept requires a neutral particle beam. The output of a nuclear shaped charge is a jet of ionized plasma.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

Which has a overall neutral charge, Casaba fusion pumped particle weapon produces quasi neutral plasma.
Arioch wrote:The PROCSIMA concept requires a neutral particle beam. The output of a nuclear shaped charge is a jet of ionized plasma.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by icekatze »

hi hi

First of all, PROCSIMA is still really hypothetical, and there are a lot of reasons why it might not work.

Second of all, it requires an absolutely neutral charge, not an overall neutral charge. Any transverse interactions between atoms being drawn toward each other by electromagnetism would ruin the hypothetical effect.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

All neutral plasma is "quasi neutral" the laser would effect a Casaba Howitzer beam in this regard just fine.
I got a second opinion.
Gradient pressure isn't theory, you can pick up a speck of graphite from a pencil with a decent laser pointer at home.
icekatze wrote:hi hi

First of all, PROCSIMA is still really hypothetical, and there are a lot of reasons why it might not work.

Second of all, it requires an absolutely neutral charge, not an overall neutral charge. Any transverse interactions between atoms being drawn toward each other by electromagnetism would ruin the hypothetical effect.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Mjolnir »

MBehave wrote:All neutral plasma is "quasi neutral" the laser would effect a Casaba Howitzer beam in this regard just fine.
I got a second opinion.
Gradient pressure isn't theory, you can pick up a speck of graphite from a pencil with a decent laser pointer at home.
Quasi-neutral or not, the interaction of plasma with light is very different from that of neutral atoms. What you want is an extremely uniform column of cold neutral atoms extending from your beam generator to the target with a very narrow distribution of particle velocities. The idea is to shine a laser down through the entire column, so you don't actually want much matter in it.

What the Casaba Howitzer gives you is a more or less directional blast of vaporized and mostly-ionized bomb material that is likely to also vaporize your laser source, making the fact that it's largely opaque to electromagnetic radiation fairly irrelevant.

Edit: also, you're going to need more than a laser pointer to levitate anything. You're going to need both a couple orders of magnitude more power and a laser source of sufficient quality to be focused to a tiny area. Since you mention graphite, you're probably thinking of optical manipulation of magnetically levitated graphite.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by icekatze »

hi hi
MBehave wrote:Gradient pressure isn't theory...
Could you maybe unpack this a little bit? I don't know of any Law of Gradient Pressure. Are you talking about Newton's Second Law of Motion, Pascal's Law, or maybe the Ideal Gas Law? Why does it matter if there is a theory behind it or not?

Also, if you're talking about optical levitation, you want a transparent, dielectric material, not graphite. And you're going to want at least 1 Watt for a 50 micrometer diameter sphere. Laser pointers are generally 5 milliwatts or weaker.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

Youtube has quite a few laser levitation videos using cheap laser systems at home.

From dust to graphite from a pencil to tiny diamonds.
Sprinkle the tiny dust/lint/graphite particles through the beam and some will get trapped and you can move the laser around with them trapped inside. If you can modify the focus you can move the particle up and down the beam.

I thought it was same method as optical tweezers using gradient of force.

The argument was the beam had to be true neutral for a laser to be coupled with it.
It does not.
It also does not need to be cold.
The beam does need to be monoenergetic, the hydrogen particles having like energy level.

Which is a hurdle for a Casaba and I was told pretty much impossible.

The fact its happening in a firechamber and the beam is getting processed means its not out of the question IF the technology for the magnetic fields is there. Which has been my premise all along, the magnetic field strength for the Terran railguns is of such power using a firing chamber to collimate the beam shouldn't be impossible.

200kg to 400km/s almost 4 megatons over very small surface area and a length of 10m or so.
Such a weapon isn't possible, but it is in outsider so jumping on that technology as a basis I am saying the Ship mounted Casaba Howitzer is possible in this regard.


Ok
I didn't work this out Matterbeam at ToughSF did.
400km/s in 10m is an average acceleration of 8000000000 m/s^2. Acting on 200kg, that's a force of 1.6 teraNewtons. If the projectile is 10cm wide at the base, the magnetic pressure could be the equivalent of 2e14 Pa, or 203 teraPascals.
It is hard to give an atomic bomb a 'pressure' in space, but in general terms you will need about 1 Pa to contain 1 joule in 1 cubic meter. Therefore, 2e14 Pa can contain the yield of 47.8 kT inside 1m^3.
A firing chamber 20m across can contain 100mt fusion reaction easily using the same level of technology behind the Terran Railguns.
So the only technological hurdle left working out if its possible to process the hydrogen beam to be monoenergetic.

icekatze
Laser beam with a differing intensity between the core and the edge has a gradient of force when that beam interacts with particles.
Mjolnir wrote:
MBehave wrote:All neutral plasma is "quasi neutral" the laser would effect a Casaba Howitzer beam in this regard just fine.
I got a second opinion.
Gradient pressure isn't theory, you can pick up a speck of graphite from a pencil with a decent laser pointer at home.
Quasi-neutral or not, the interaction of plasma with light is very different from that of neutral atoms. What you want is an extremely uniform column of cold neutral atoms extending from your beam generator to the target with a very narrow distribution of particle velocities. The idea is to shine a laser down through the entire column, so you don't actually want much matter in it.

What the Casaba Howitzer gives you is a more or less directional blast of vaporized and mostly-ionized bomb material that is likely to also vaporize your laser source, making the fact that it's largely opaque to electromagnetic radiation fairly irrelevant.

Edit: also, you're going to need more than a laser pointer to levitate anything. You're going to need both a couple orders of magnitude more power and a laser source of sufficient quality to be focused to a tiny area. Since you mention graphite, you're probably thinking of optical manipulation of magnetically levitated graphite.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Mjolnir »

Any optical tweezer demos done with low power lasers are using lasers that are still many times more powerful than a laser pointer, and manipulating particles suspended in a fluid, using thermal effects on the liquid or air surrounding the particles. It should be obvious why this wouldn't work on gas particles in a vacuum.

The beam has to be neutral particles. Being neutral overall is not sufficient. The problem with plasma isn't that it doesn't interact with light, it'll interact quite well, and you won't get your focused beam, you'll just get some hotter and faster expanding plasma. It also absolutely does have to be cold. The confining effect of the laser is not strong, and if the molecules are moving too quickly they will escape. They also need to occupy a very narrow range of velocities in terms of overall beam motion, or they will collide with each other, convert the motion to heat, and escape. Additionally, doppler effects will change how the beam interacts with the particles. You want something as close as possible to a bunch of particles flying in formation to the target.

Ionized hydrogen consists of free electrons and protons. The whole concept of energy levels only applies to bound systems...neutral hydrogen.

You need a continuous beam of transparent, extremely uniform, cold, high and very consistent energy, neutral gas of sufficiently low density that a laser can travel along the length of the entire beam to the target with little attenuation. A nuclear device is not a reasonable approach to generating such a beam.

And as icekatze said, it's not clear how workable PROCSIMA actually is. The system seems certain to be unstable at best. Basic conservation of momentum makes a strong argument that you can't keep deflecting both neutral atoms and photons near the edge of the beam inward to keep the beam collimated.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Mjolnir »

MBehave wrote:A firing chamber 20m across can contain 100mt fusion reaction easily using the same level of technology behind the Terran Railguns.
Accelerating a couple hundred kg of inert projectile is nothing at all like confining a detonating thermonuclear weapon in a chamber tens of meters across. How can you suggest the two are anything like equivalent?

MBehave wrote:So the only technological hurdle left working out if its possible to process the hydrogen beam to be monoenergetic.
And all the other stuff. Oh, and justifying such a mechanism for generating cold, uniform neutral particle beams when there's got to be about a billion more suitable approaches.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by MBehave »

The peak field strengths required ARE alike, or actually less for the fusion chamber.
Mjolnir wrote:
MBehave wrote:A firing chamber 20m across can contain 100mt fusion reaction easily using the same level of technology behind the Terran Railguns.
Accelerating a couple hundred kg of inert projectile is nothing at all like confining a detonating thermonuclear weapon in a chamber tens of meters across. How can you suggest the two are anything like equivalent?

MBehave wrote:So the only technological hurdle left working out if its possible to process the hydrogen beam to be monoenergetic.
And all the other stuff. Oh, and justifying such a mechanism for generating cold, uniform neutral particle beams when there's got to be about a billion more suitable approaches.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Siber »

I'm not going to dig into everything else at the moment, but I am curious where the 10m barrel length figure is coming from. I understood the weapon to be fixed mounts because if it's size, and the smallest ship that carries a heavy mass driver is almost 300m. Was there word of god on this somewhere that I missed?

It probably doesn't make much difference in the final mathing because the forces involved in accelerating a projectile even over that length are still going to be bonkers, but I am still curious.
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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Mjolnir »

MBehave wrote:The peak field strengths required ARE alike, or actually less for the fusion chamber.
Except you have to apply those fields with a field topology suitable for bottling and directing plasma across a chamber with about a million times the volume, containing an explosion generating immense amounts of heat and neutrons. These things are nothing alike in their technological requirements.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by icekatze »

hi hi
MBehave wrote:icekatze
Laser beam with a differing intensity between the core and the edge has a gradient of force when that beam interacts with particles.
So... what does this have to do with gradient pressure not being a theory? Why does it matter if it is a theory or not? I still don't know which law you're referring to.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by icekatze »

hi hi
Siber wrote:I'm not going to dig into everything else at the moment, but I am curious where the 10m barrel length figure is coming from.
I'm not sure if there's a hard number anywhere, but it seems that the barrels on the railguns are pretty short compared to the whole ship, based on the image of the America that Arioch made.

At those sizes, and those power levels, I have a feeling that those mass drivers are meticulously maintained to avoid sudden, unplanned failure of the firing chamber. I would expect that they'd be considered very state of the art by today's standards, and probably not at all cost effective as expendable munitions themselves.

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Re: Terran Nuclear Tech (split from Terran Q&A)

Post by Siber »

The barrels could run most of the length of that wing structure, which is a lot bigger than 10m long. I'd eyeball it at 50-70% of the length of the ship. Since we've got profile views of the ships I tried matching the sideview features and came up with close to 54%, so on a 320m ship lets call it 170m for round numbers.
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