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Post by ironclad6 on Aug 29, 2017 4:56:27 GMT
Guys, feel free to add to this list of shit I have to work out. While I'm thinking about it. All of the Systems Commonwealth designs are underweight. The "Rocket" modules serve as standins for her magnetic confinement nozzles but I need to work out a couple of things.
1) There should be a stellarator module standin somewhere from which I should be able to harvest some usable energy in proportion to my total thrust power. I also need to make a final decision about what kind of fusion reaction I'm going to use.
2) I need to consider, select and design a potential replacement for my metallic hydrogen munitions.
3) I need to work out how I'm igniting my stellarator when I neet to GTFO in a hurry.
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Post by bigbombr on Aug 29, 2017 6:02:16 GMT
Guys, feel free to add to this list of shit I have to work out. While I'm thinking about it. All of the Systems Commonwealth designs are underweight. The "Rocket" modules serve as standins for her magnetic confinement nozzles but I need to work out a couple of things. 1) There should be a stellarator module standin somewhere from which I should be able to harvest some usable energy in proportion to my total thrust power. I also need to make a final decision about what kind of fusion reaction I'm going to use. 2) I need to consider, select and design a potential replacement for my metallic hydrogen munitions. 3) I need to work out how I'm igniting my stellarator when I neet to GTFO in a hurry. 1) Perhaps look at resource availability: some factions might use one reaction and others might use another based on availability. A sub-optimal fuel with guaranteed access beats a more optimal fuel which can be blockaded by the enemy. Variety (especially in lore) is the spice (must flow) of life. 3) Tactical nuke to ignite the fuel, harvest the energy with magnetohydrodynamics, use the harvested energy to kickstart 'conventional' fusion. |
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Post by Kerr on Aug 29, 2017 8:40:14 GMT
Guys, feel free to add to this list of shit I have to work out. While I'm thinking about it. All of the Systems Commonwealth designs are underweight. The "Rocket" modules serve as standins for her magnetic confinement nozzles but I need to work out a couple of things. 1) There should be a stellarator module standin somewhere from which I should be able to harvest some usable energy in proportion to my total thrust power. I also need to make a final decision about what kind of fusion reaction I'm going to use. 2) I need to consider, select and design a potential replacement for my metallic hydrogen munitions. 3) I need to work out how I'm igniting my stellarator when I neet to GTFO in a hurry. 1. D-T fusion might be completly unfeasible, the only source of tritium I know of is from Water-cooled nuclear reactors, which will most likely be replaced with thorium-salt reactor. D-He3 can be aquired from gas giants, it has overall the best performance of any fuel, relatively easy to ignite, and produces 75% protons as the reactions output. Those helium-3 filters on gas giants are easy targets thought and can possibly cripple an entire empire within few months. p-B11 is pretty common, very hard to ignite, it's Lawson Criterion is 31x higher than that of D-He3, it's exhaust velocity is half of that of D-He3, you can only ignite this stuff with particle beam. But still it's exhaust velocity is still sufficant. 2. Maybe you want to consider an NTR? I've got my 600g NTR up to a exhaust velocity of 11.4km/s. Which pretty damn near to that Metallic Hydrogen. 3. Antimatter. 1-10 micrograms of it can ignite pretty much any fusion fuel due to it's enourmous annihilation energies. And don't worry, a microgram will only result rougly 20kg TNT. As an alternative, an Fusion reactor, if your setting has the tech for high efficiency magnetic nozzle and near 100% burning rates then why not use it in an actual stellerator. Use D-He3 in it and with a single ton of it you can supply your ship with 33GW for 3 years. |
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Post by matterbeam on Aug 29, 2017 9:15:27 GMT
Guys, feel free to add to this list of shit I have to work out. While I'm thinking about it. All of the Systems Commonwealth designs are underweight. The "Rocket" modules serve as standins for her magnetic confinement nozzles but I need to work out a couple of things. 1) There should be a stellarator module standin somewhere from which I should be able to harvest some usable energy in proportion to my total thrust power. I also need to make a final decision about what kind of fusion reaction I'm going to use. 2) I need to consider, select and design a potential replacement for my metallic hydrogen munitions. 3) I need to work out how I'm igniting my stellarator when I neet to GTFO in a hurry. You only really need to power up the proton accelerator and have some current running through the drive's electromagnets. The first pulse of fusion power won't be completely captured by the drive coils working in reverse to slow down the charged particles and generate electricity. You will recuperate more energy than expended however. Second pulse, drive coils with more current, even more energy collected. At full power, you can start shifting the fusion power to generating thrust. A simple 10 ton fission reactor assembley, pumpa, radiators and all, can produce over 7.2GJ when running for an hour. More than you can store! For rapid startup power, use a flywheel. However, I am of the opinion that keeping the fusion engine running in very low power mode with 100% MHD, like one pulse a minute, using no propellant other than the fusion products, will consume negligible amounts of fuel while providing more power than you could ever need. If you enter combat and somehow don't want to accelerate, pump the fusion reaction rate up and use larger pulses for terawatts of electricity. That will keep the lasers fed. |
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Post by matterbeam on Aug 29, 2017 9:27:57 GMT
Kerr: I must note that while proton boron reaction are clean, use plentiful fuels (boron11 is 80% on natural boron) and produce 8.6MeV per boron reaction, it would be strongly contested by D-T reactions where neutrons are absorbed and converted into heat by something like a boron shell around the fusion fuels...
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Post by Kerr on Aug 29, 2017 9:38:59 GMT
Kerr: I must note that while proton boron reaction are clean, use plentiful fuels (boron11 is 80% on natural boron) and produce 8.6MeV per boron reaction, it would be strongly contested by D-T reactions where neutrons are absorbed and converted into heat by something like a boron shell around the fusion fuels... 14.1 Mev Neutrons can penetrate up to 2cm into matter before any significant amount of neutrons are absorbed. Also how do you want to get large quantities of tritium? Breeders? In Polyethylene 50% of the neutrons are absorbed at 5cm. And that your boron is 5 times better at absorbing than PE. 100g frozen D-T, 1L volume. 1cm Boron shell. 1.3L volume of the boron shell. Resulting in 3kg of Boron. Even if the boron 10x better you'd still need 1.3kg for every 100g D-T. Even most Li-6 radshields are much thicker than that, and they have to deal with neutrons that ary 5 times weaker. |
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Post by matterbeam on Aug 29, 2017 10:20:18 GMT
Kerr : I must note that while proton boron reaction are clean, use plentiful fuels (boron11 is 80% on natural boron) and produce 8.6MeV per boron reaction, it would be strongly contested by D-T reactions where neutrons are absorbed and converted into heat by something like a boron shell around the fusion fuels... 14.1 Mev Neutrons can penetrate up to 2cm into matter before any significant amount of neutrons are absorbed. Also how do you want to get large quantities of tritium? Breeders? How did you get that neutron absorption depth? Lithium-6 represents 7.5% of natural lithium, and readily converts into tritium under neutron bombardment. Not a lot of it is needed to produce terawatts of power either. I mean, its much more common than fissile fuels and we can make it out of practically limitless supplies of lithium, so sourcing it should not be a major issue. |
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Post by Kerr on Aug 29, 2017 10:31:51 GMT
14.1 Mev Neutrons can penetrate up to 2cm into matter before any significant amount of neutrons are absorbed. Also how do you want to get large quantities of tritium? Breeders? How did you get that neutron absorption depth? Lithium-6 represents 7.5% of natural lithium, and readily converts into tritium under neutron bombardment. Not a lot of it is needed to produce terawatts of power either. I mean, its much more common than fissile fuels and we can make it out of practically limitless supplies of lithium, so sourcing it should not be a major issue. Correction. Neutron absorbtiond peaks at roughly 2cm. Before that energy amount are still pretty high. I got the number from Fourth Generation Nuclear Weapons: Military effectiveness and Collateral effects" the example was for Polyethylene, but the depths shouldn't change much because inelstatic and elastic scattering cancel each other out. Even if 5mm Boron shell can absorb 50% of the energy it would weight 1.3kg for every 100g D-T, it might be less if you use somethinh likd LiDT, or an small DT charge surrounded by LiD. I've did the math. If the DT was in form of an LiD ball then the balls volume is only 125cm3. A 5mm Boron shell would weight 300g. If this shells absorbs 100% of the neutrons it will improve the exhaust by an factor of 1.18x. At 75% it won't really at all besides absorbibg most of the lethal neutrons. But I don't think an 5mm thick shell could absorb anything near that. Heck, I question if 0.5cm Li-6 can stop radiation from a normal reactor. Also shouldn't the boron ions have similiar problems to that of the water afterburner? To get back to the water afterburner. Oxygen ions might have worse charge-ratio than the alpha particles. But they are also alot slower and have way less kinetic energy. A 10x thrust boost requires 100x more mass. Making the average particle 10x slower. |
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Post by Kerr on Aug 29, 2017 15:54:42 GMT
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Post by ironclad6 on Aug 29, 2017 16:27:59 GMT
I am reading and researching at the moment. I have a quick question though. Do you know of any fusion power mods and would that be the best way to represent my stellarator core? Is there a relationship between how much power I can generate to power on board systems and my total thrust power? If so, what is it?
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Post by Kerr on Aug 29, 2017 16:41:34 GMT
I am reading and researching at the moment. I have a quick question though. Do you know of any fusion power mods and would that be the best way to represent my stellarator core? Is there a relationship between how much power I can generate to power on board systems and my total thrust power? If so, what is it? KSP Interstellar comes in mind. For CDE they are non. You can use an black box module though. Depends on how do you even power your ship. If with MHD's then yes. Otherwise no. If you use an reactor to power the fusion drive without MHDs of any kind. Yes. You have to decide between fusion ignition methods. In most cases your power input correlates into your output. matterbeam Is it even entirely safe to use MHDs in a fusion drive? These are still millions to billions kelvin beams moving at multiple percent of c. |
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Post by ironclad6 on Aug 29, 2017 16:50:09 GMT
How does an MHD draw power from a stellarator and what is a black box module?
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Post by Kerr on Aug 29, 2017 17:01:29 GMT
How does an MHD draw power from a stellarator and what is a black box module? In an D-He3 Stellerator protons are catched by the magnetic field and directed into the MHD. Comparing Stellarator and fusion a drives MHD is like an fission reactor and nuclear bombs turning water into steam. Fundamentaly the same but on a completly different order of magnitude. Black box modules are either weapons, propulsion, reactors. I think they are the most right icon on each list. Go to atomic rockets pick an fusion drive and replicate them into your black box module. You can pick fuel, exhaust velocity, mass flow and even power demnand I think. |
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Post by ironclad6 on Aug 29, 2017 17:23:52 GMT
So, if I understand your suggestion, I'd have a stellarator from which I can draw electrical power in proportion to my thrust power. I'd need a secondary piwer plant for hotel load and to power my particle accelerator. A couple of massive flywheels for startup juice and a number of magnetic confinement nozzles to direct the thrust generated in my stellarator. The MC nozzles would have to be fed fusion products from the stellarator and power from the powerplant to maintain their fields? This is surprisingly similar to my original design idea.
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Post by Kerr on Aug 29, 2017 17:38:34 GMT
So, if I understand your suggestion, I'd have a stellarator from which I can draw electrical power in proportion to my thrust power. I'd need a secondary piwer plant for hotel load and to power my particle accelerator. A couple of massive flywheels for startup juice and a number of magnetic confinement nozzles to direct the thrust generated in my stellarator. The MC nozzles would have to be fed fusion products from the stellarator and power from the powerplant to maintain their fields? This is surprisingly similar to my original design idea. my suggestion is 1. Get an decent fusion reactor providong both hotel and medi ocre engine and weapon power. 2. Use the fusion reactor to power your engine. Flywheels have to charge. And when you already used your charge and have to wait to recharge, then you are fucked if something attacks. 3. Put MHDs around your magnetic nozzle. Why? Because magnetic nozzles are never 100% efficant. A good nozzle has 85% efficiency meaning 15% escape. Absorb 1-10% of the particles. My 16MN D-He3 engine has a 163TW Thrust power. 24.5TW escape. 2.45TW hit the MHD's. At 50% efficiency you get 1.2TW power. Theres a problem. You have to deal with 1.2TW of heat deposited in your MHD. And you most likely want more than 16MN. So you end up with few terawatts. Sufficant to provide mayhem. |
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