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Post by shurugal on Nov 2, 2016 17:20:52 GMT
So I made a thing. I think I'll try to make a <100 ton drone with it and some MPD thrusters More seriously, the laser rod is way too small diameter for 42.6 MW of 1064nm, 112GW/m^2 . (oh and the end mirrors won't take it either, dielectric mirrors please!) The thermal stress in the rod will probably shatter it as well. ("just" 11.6MW of volumetric heating to deal with.) Finally, can we have an incandescent lamp pump source please? (i.e. a black body) I think it'll make Erbium and Ytterbium doped lasers more viable. It also opens up the possibility of using a nuclear reactor's fuel rods as the black body pump source. I'd LOVE a nuclear pumped Nd:Diamond laser (A black body pumped laser is a common concept explored by the few researchers looking at solar powered lasers) I'd like to have a CO2 laser. They're significantly more efficient than the solid state types we use in the game currently (according to wikipeida they can reach inefficiencies of 20%!), so output powers could be much higher than what we get currently. Edit: That said, I did experiment with a 100% efficient 300MW black box laser. It wasn't as awesome as I'd hoped. The biggest reason I would like to see more efficient laser types is that it would make building a death-array of many small lasers much more practical, and infinitely scalable.
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Lasers
Nov 2, 2016 18:18:26 GMT
Post by redparadize on Nov 2, 2016 18:18:26 GMT
Laser should be buffed a bit, in a non-physics breaking way of course. Cost and mass would be reasonable. I slight nerf would be welcome too, I am not convinced that you could remain pin point accurate at 250km... A small wobble would be welcome.
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Post by apophys on Nov 2, 2016 21:02:11 GMT
In any case, the main reason I came to this thread is to ask the following: Are there any wavelengths that are particularly common, useful, or powerful? I ask because if there were, then it would be interesting to implement metamaterial cloaking as a counter; because they currently exist, but can only really affect a handful of wavelengths at the same time; not all wavelengths at once (full true invisibility). With the materials available, the only 2 wavelengths that are significantly used are frequency-doubled Nd:YAG + krypton (green, 532 mm) and frequency-doubled Ti:Sapphire + xenon (purple, 395 mm). That's because the power efficiency for those combos is higher than anything else by a fair margin. Frequency doubling is basically always used, for a much better intensity with no serious downsides. You could try aluminum for purple and silver for green, because that's the material they use for their focusing mirrors. Also both materials reflect the other color decently. The trade-off between the two is that purple gets better intensity, but less raw power. Purple gets more efficient at low power levels, but still not more than green.
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Post by jonen on Nov 2, 2016 21:18:03 GMT
The trade-off between the two is that purple gets better intensity, but less raw power. Purple gets more efficient at low power levels, but still not more than green. Green vs Purple.
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tuna
New Member
Posts: 33
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Post by tuna on Nov 3, 2016 1:16:31 GMT
I am not convinced that you could remain pin point accurate at 250km. You'd be wrong. The hubble space telescope has a precision of 0.007 arcsec. This means that at 250km, the telescope will not wander more than 0.025mm from it's aiming point. That is smaller than the diameter of a human hair. The game chooses to have all turrets rotated with momentum wheels. This has drawbacks in making large turrets really expensive to turn, with most of the weight of the turret in the reaction wheels. However, reaction wheel systems can truly be crazy stable and precise.
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Lasers
Nov 3, 2016 1:57:44 GMT
Post by RA2lover on Nov 3, 2016 1:57:44 GMT
The HST doesn't have a gigawatt of power being pumped through it, though. That's enough power flowing through to throw off the weapon's aim.
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Lasers
Nov 3, 2016 16:08:31 GMT
via mobile
Post by dragonkid11 on Nov 3, 2016 16:08:31 GMT
So erm, I tried to build a laser ship with 10 1 gigawatt lasers.
Tried.
For some reasons, the game outright crashed and exited when I tried to play it in sandbox.
I tested the component in a single gigawatt laser ship version and they work perfectly fine.
So now I'm just really not sure on what broke inside it.
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Lasers
Nov 3, 2016 16:14:06 GMT
via mobile
Post by Durandal on Nov 3, 2016 16:14:06 GMT
The HST doesn't have a gigawatt of power being pumped through it, though. That's enough power flowing through to throw off the weapon's aim. You mean motion from the coolant pumps or something? "Power" itself shouldn't be a problem, and beyond the turbopump nuclear reactors don't have (m)any moving parts from what I understand.
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Post by Easy on Nov 3, 2016 16:30:58 GMT
I am not convinced that you could remain pin point accurate at 250km. You'd be wrong. The hubble space telescope has a precision of 0.007 arcsec. This means that at 250km, the telescope will not wander more than 0.025mm from it's aiming point. That is smaller than the diameter of a human hair. The game chooses to have all turrets rotated with momentum wheels. This has drawbacks in making large turrets really expensive to turn, with most of the weight of the turret in the reaction wheels. However, reaction wheel systems can truly be crazy stable and precise. The HST doesn't rapidly aim at maneuvering targets in real time from a wobbly, accelerating platform. Also the HST uses long exposure times on a single target.
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Post by goduranus on Nov 3, 2016 19:11:09 GMT
More on aerogel armor vs lasers, maybe there is a solution to aerogel? So, I was testing some armor configurations, and added a 0.5mm layer of aluminum on top of the aerogel, thinking that aluminum's reflectivity will make the aerogel better. To my surprise, aerogel that is coated with aluminum got destroyed by lasers more quickly. I think what happened was that aluminum was conducting heating, and that melted the aerogel. That got me thinking, aerogel has really low melting point, at 800k, the power needed to melt it is only something like 65kW/m^2, and the problem with big lasers not burning through aerogel, probably has to do with their power being concentrated on a spot too tiny to be hit repeatedly. I made a laser with a relatively small lens, so that it only puts out 70kW at 250km, just enough to destroy the aerogel. I put 20 of them on the ship, which I think helps because lasers are essentially pulsed, with one "hit" per "tick" in the game, so more lasers is more hits per tick, and will whittle down the aerogel faster. The results are okay, I guess,burning through 20cm of aerogel sloped at 60 degrees in 60 seconds. To actually destory a ship though, there also needs to be a big-lens laser on the ship to get through the metal behind the aerogel. A bigger version of the setup with 20 50MW lasers that produce 100kW/m^2 at 250KM, for hitting a much bigger area per tick, was faster than the 20x6.5MW setup, burning that same 20cm of aerogel sloped at 60 degrees in 20 seconds. Also showing that the aerogel-burning small-lens lasers are completely ineffective against metal armor, which likely has a higher melting point.
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reviire
New Member
I'm pretty great
Posts: 44
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Lasers
Nov 4, 2016 2:02:39 GMT
Post by reviire on Nov 4, 2016 2:02:39 GMT
Can someone explain to me where exactly I've messed up here? The efficiency seems fine, but the graph looks a bit... weird? puu.sh/s5LSK.jpg
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Post by cuddlefish on Nov 4, 2016 2:12:28 GMT
Well, you have coolant going in at 50k and coming out at 167k - that's going to be next to impossible to radiate, as you're keeping the thing well below 0 C and heat engines aren't implemented. That's what's causing the blue background in the laser image - the color there represents the temperature inside the laser itself.
Or, if you meant the intensity graph on the left side, I think the X-axis extent is set by the max range you've input on the right hand side, and it's having trouble graphing intensity out to what appears to be a distance of 1km as the limit.
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reviire
New Member
I'm pretty great
Posts: 44
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Post by reviire on Nov 4, 2016 2:49:36 GMT
Well, you have coolant going in at 50k and coming out at 167k - that's going to be next to impossible to radiate, as you're keeping the thing well below 0 C and heat engines aren't implemented. That's what's causing the blue background in the laser image - the color there represents the temperature inside the laser itself. Or, if you meant the intensity graph on the left side, I think the X-axis extent is set by the max range you've input on the right hand side, and it's having trouble graphing intensity out to what appears to be a distance of 1km as the limit. Oh well, fuck. Can't believe I missed that. Thanks anyway, as for the coolant yeah, I was wondering if lasers needed their own radiators, just haven't used one yet. But it shouldn't be an issue, I hope.
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Post by apophys on Nov 4, 2016 6:24:51 GMT
With reactor temp at 2500K (standard for me) and laser temp at 1234K (barely below silver's melting point), laser radiators take up about twice the space of reactor radiators (with reactors powering almost nothing else).
Combined radiators are the #1 element in my MPD laser ship in terms of both mass and cost, even though the radiators have minimum thickness and are made of light, cheap materials. So radiator temperature is a big deal if you're focusing on lasers.
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Lasers
Nov 4, 2016 7:16:23 GMT
Post by goduranus on Nov 4, 2016 7:16:23 GMT
That 10GW reactor someone posted was a major breakthrough, ultra-high deltaV ships and huge laser arrays are no problems now.
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