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Post by Lukander on Mar 4, 2017 19:11:06 GMT
Yes, but the outgoing intensity you're listing is the intensity at the ~target point~. Not what the focusing mirrors themselves experience, which is my point.
"damaging" the mirrors just requires enough heat to affect reflectivity across some of its surface. That requires far less than causing any noticeable meltage in the material.
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Post by apophys on Mar 4, 2017 20:23:43 GMT
Yes, but the outgoing intensity you're listing is the intensity at the ~target point~. Not what the focusing mirrors themselves experience, which is my point. "damaging" the mirrors just requires enough heat to affect reflectivity across some of its surface. That requires far less than causing any noticeable meltage in the material. One of the very first lasers I made on the forum had ~2.5 MW/m 2 of intensity at the outgoing mirror (before the second frequency doubler was available). You can easily make one with 1 GW / m 2. The game will only throw an error for aluminum mirrors when the outgoing intensity passes 1.27 GW / m2.
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Post by leerooooooy on Mar 4, 2017 20:32:30 GMT
Um, reflective surfaces don't really help with resisting weaponized lasers though. At the energy densities(at the point focused on) used to damage a target, any materials reflective properties are ruined when it heats up. That's why "reflective" armor is considered a bad SF cliche... Your own lasers avoid destroying themselves when they fire because the beam of coherent light is only that tightly focused when exiting the focusing device(ideally at there tightest focus at the targeted point) Our own lasers are putting up to a few GW/m2 on their own mirrors, and survive those just fine. Then they die after getting hit by 1 MW/m2 lasers on the same wavelenght, which makes no sense
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Post by Lukander on Mar 4, 2017 21:23:25 GMT
Ah, after further clarification that does seem off. My apologies.
A calculation error or simulation short-cut in the game engine perhaps?
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Post by Rocket Witch on Mar 4, 2017 23:29:46 GMT
A calculation error or simulation short-cut in the game engine perhaps? Oversight I think. If it works like armour, laser mirrors probably don't have any thickness defined, so they're either intact or destroyed and nothing in between. If not, it seems the game doesn't check for the remaining margin in the intensity threshold, it just considers a laser to be inoperable once it is flashed with no actual damage modelling taking place, just flipping a boolean. Oh, there is also the matter of a laser not being able to reach the optics of another anyway due to all that light issuing forth from it already. This is what makes inertial-confinement fusion difficult; it's like trying to block off a water hose by shooting another stream of water into it. The new laser weapon models in CDE suggest the mirror does have to be exposed though? I don't know how lasers actually work but this might be a point worth raising.
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Post by lawson on Mar 5, 2017 1:58:30 GMT
Also note even a little damage to the mirrors will ruin there ability to properly focus the beam. No it won't. Minor scarring will scatter some of the outgoing beam and increase the spot size a bit. Sand-blasting half the mirror will scatter half the beam and increase the spot size by up to 2x or so. A good melted track would distort the shape of the mirror and is likely to massively increase the spot size. (note, this needs 10-100MW/m^2 intensity, a few centimeter diameter spot, and enough control to partially melt a track in the mirror)
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Post by StalkerJames on Mar 5, 2017 2:00:17 GMT
Even though the primary mirror can withstand GW/m2 intensity, what about the secondary mirror(beam expander). The secondary mirror requires its own cooling system and struts to support it, and they are vulnerable to enemy laser fire.
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Post by deltav on Mar 5, 2017 2:48:41 GMT
Here's a little drawing I did of how I think our laser turrets work. The laser beam is not focused until it hits the variable optic focusing mirror inside the turret. The unfocused output from the laser is fed to the turret most likely using a fiber optic cable system. This is then fed to the turret where it hits the prefocusing mirror (in red) and then the variable optic focusing mirror, that focuses the laser based on distance to target. If you hit the prefocusing mirror (in red) with a laser, you just have to deform it enough to damage its optical properties, and that can knock out the laser. That's my working theory of how very powerful lasers are being knocked out with weak ones. Small lasers with small apertures are perfect for this because they would have smaller prefocusing mirrors and a smaller focused beam size.
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Post by deltav on Mar 5, 2017 5:11:51 GMT
I believe laser threshold just means you need that much intensity to reach the full ablation rate. It's no guarantee the ablation rate under that threshold is low enough to make a good armor. that's not reasonable, since those materials work fine with intensities near the threshold when inside a laser, and if they ablated at all the laser should not work Also the variable optic mirror is made of Aluminum, but so is the default whipple shield, one melts but the other is fine. Why? The focusing mirror is specially cut and polished to a shine to reflect almost all light instead of absorbing it, while the whipple shield is not. The full power of the beam never contacts any part of the laser because it does not come to full power until it leaves the focusing mirror at the last step at creating a laser beam, although the focusing mirror experiences the highest intensity. The materials may be the same, but the polishing/finishing is not the same, and when it comes to lasers, that's pretty important.
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Post by deltav on Mar 5, 2017 6:06:17 GMT
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Post by deltav on Mar 5, 2017 13:56:42 GMT
PS I was thinking about how our laser mounts/turrets close over with armor with the "hatch" completely closed. The best I could think of is some type of Iris hatch, but this doesn't explain everything... where are the "hatch" panels hiding? Love this new update.
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Post by Enderminion on Mar 5, 2017 14:29:18 GMT
PS I was thinking about how our laser mounts/turrets close over with armor with the "hatch" completely closed. The best I could think of is some type of Iris hatch, but this doesn't explain everything... where are the "hatch" panels hiding? Love this new update. In the rest of the turret most likely
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Post by deltav on Mar 5, 2017 14:43:43 GMT
Enderminion , I mean there is no room for the panels of the iris. The turret would have to be bigger, or the opening smaller. Edit:Maybe if they curve outward and downward in 3 dimensions somehow. But no current iris design works that way... as far as I know.
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Post by apophys on Mar 5, 2017 18:17:29 GMT
The incoming laser intensity at the aperture (big mirror) is much, much less than outgoing laser intensity at the same aperture. They are both proportionally more concentrated at the smaller focusing mirror (thanks for pointing out its location, deltav ). The outgoing beam is still much, much stronger at that location. For there to be any damage to any component, such as the focusing mirror, the combined intensity of incoming and outgoing beams would have to be greater than a certain number, " Lasing Damage Threshold." For Aluminum the threshold is 1.27 GW/m 2. For silver that is 4.46 GW/m 2. For titanium dioxide that is 129 TW/m 2. This is accounted for when producing the outgoing beam. This does not appear to be accounted for when receiving an incoming beam. Thus, the bug. Edit:Maybe if they curve outward and downward in 3 dimensions somehow. But no current iris design works that way... as far as I know. Let me Google that for you:
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Post by lawson on Mar 5, 2017 18:48:19 GMT
Let me Google that for you: Nifty As shown in the photo, most flat mechanisms can be projected onto a spherical surface and still work. That said, I think the game just uses a big flat door that flips up and out of the way. (K.I.S.S. and all that) It just hasn't been a priority to render the telescope cap when it's open.
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