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Lasers
Oct 6, 2016 3:32:54 GMT
Post by nivik on Oct 6, 2016 3:32:54 GMT
It can potentially change the center of mass and moment of inertia enough to reduce the time required to change heading. Hmm. That's true. Also a hot drone under power is still a target that the enemy ship will consider a target, which is a merit all its own.
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Lasers
Oct 6, 2016 3:45:39 GMT
Post by ross128 on Oct 6, 2016 3:45:39 GMT
Even if you moved the ammo storage, when a gun is destroyed it leaves a hole in the armor where it was. For most drones, that's the entire nose cone, and if the drone is facing you (it usually is) that's it's entire front cross-section.
Basically as soon as the gun goes, the only thing between you and coring it completely is the fuel tank.
I can also say that after testing, I cannot emphasize enough how important it is to always have something, anything, targeted if you're laser boating. Even a centimeter of Silica aerogel can take hours to burn through if your lasers are randomly raking across the hull, but if you target anything at all the lasers will all converge on a single point and burn right through it.
Crew module radiators are particularly good targets though because they tend to be flimsy, and if they pop then all the crew modules cook.
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Lasers
Oct 6, 2016 5:03:54 GMT
Post by Dhan on Oct 6, 2016 5:03:54 GMT
It can potentially change the center of mass and moment of inertia enough to reduce the time required to change heading. If anything it should make it worse as you'd be moving the mass closer to the engine.
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Lasers
Oct 6, 2016 5:52:24 GMT
Post by blothorn on Oct 6, 2016 5:52:24 GMT
Some thoughts from messing around with different materials: * I cannot get tolerable pumping efficiency out of anything but Nd:YAG and titanium sapphire (and ruby, to a lesser extent; need to see if its high wavelength can overcome poor efficiency). * Molybdenum is noticeably more reflective in the shortwave IR band, but between the higher diffraction of longwave lasers and the poor pumping efficiency I am seeing for those gain media, it seems better to go with Nd:YAG or titanium:sapphire and swallow the bad reflectivity. * I wonder how clear a choice between efficiency and intensity is---is it sometimes better to put out more power over a larger area when, for example, trying to melt a thermally conductive radiator?
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Post by apophys on Oct 6, 2016 8:09:42 GMT
Some notes from me: - Irradiance can be increased greatly by buffing aperture (and turret size); output power has no simple increase once you hit 1GW power in. So I care somewhat more about output power for my lasing materials. - In my testing, Nd:YAG+krypton consistently beats Ti:Sapphire+xenon and Nd:GGG+krypton in terms of output power, which in turn consistently beat everything else. Nd:YLF+krypton exists, but the melting point makes me entirely disregard it, as it has no outstanding redeeming qualities. - I can get Ti:Sapphire to pleasant efficiency levels beyond what Nd:YAG can accomplish, but I have so far not been able to do it without a large cavity, costing enormous amounts of hydrogen mass. - I see no reason to use anything other than hydrogen as coolant. - I suspect that there's an optimal irradiance. If you're able to burn through a weapons module, you don't need to make targeting harder with a smaller focal point. It would be hilarious if you could cut ships in half with an extremely focused beam like a sword, or core drill them, but I suspect it doesn't work that way, and you'd be better off barely burning away the modules and whipple shield.
The big one:
- For me, using molybdenum instead of silver for the shell, and diamond instead of fused quartz for transparent bits, cuts output power by ~55%. It saves ~90% of the radiator surface area with a 2240K output temp. Looks like it's worth it, right?
Well, with reactors at 2500K, high-temperature laser radiators take about 22% of the area of the reactor radiators used to provide the power the laser consumes. Switching to a higher laser operating temperature saves you 62% of your original total radiator area. Considering the 55% loss of power, it's basically scaled down without any savings, and the mass of the laser+reactor is not scaled. So this is actually slightly worse.
I hope I haven't made an error in my arithmetic, because this is a big deal.
A higher reactor temperature would change this of course, but not by much, I think.
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Post by leerooooooy on Oct 6, 2016 17:33:36 GMT
I did a thing almost 2 GW of output power, and these are the lasers you can increase optical units to take dowm M 2 to 3, but that adds quite a bit of weight and price and I doubt will make them much better: one of those ships can already solo Vesta overkill without letting the enemy fire a single shot. Shaving down armour (especially on radiators) might be an idea
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aiyel
Junior Member
Posts: 83
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Post by aiyel on Oct 6, 2016 20:27:38 GMT
I was experimenting with a similar ship that had about 50 lasers facing the target at any one time, that I dubbed the Archimedes. Refitted it with your lasers, launched a pair of them.
I think my laptop nearly died. Put it up against ten enemy cutters. All ten of them simply melted before they got closer than 200km. I was getting about half a frame per second with every option bottomed out.
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Post by apophys on Oct 7, 2016 4:06:19 GMT
Try this laser. More efficient, smaller, lighter, and enormously increased intensity (123 MW/m 2 at 200km); although with less angle (45 deg.) and traverse speed (45 deg./s). Edit: an immediate update, now weighs even less at 10.6 tons. LaserModule 100 MW Titanium:Sapphire Violet Laser 2 ArcLamp GasComposition Xenon EnvelopeComposition Fused Quartz PowerSupplied_W 1e+008 Radius_m 0.06 CavityWallComposition Silver CavityCoolantComposition Hydrogen CavitySemimajorAxis_m 1 CavitySemiminorAxis_m 0.99 GainMedium Titanium:Sapphire OpticalNodes 9000000 LasingRodRadius_m 0.079 Mirror Composition Silver OutputCoupler Composition Fused Quartz CoolantTurbopump Composition Boron PumpRadius_m 0.9 RotationalSpeed_RPM 46 CoolantInletTemperature_K 1200 FrequencyDoubler NonlinearOptic Composition Silver Gallium Selenide OpticLength_m 0.026 OpticRadius_m 0.0089 ApertureRadius_m 1.6 FocusingMirror Composition Aluminum Turret InnerRadius_m 3.4 ArmorComposition UHMWPE ArmorThickness_m 0.02 ReactionWheels Composition Cadmium RotationalSpeed_RPM 44 EngagementRange_km 210 TargetsShips true TargetsShots true
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Post by apophys on Oct 7, 2016 5:44:54 GMT
By the way, here's the current version of my 1GW superlaser. Intensity at 240km is 1240 MW/m 2, mass is 46.9 t, and cost is 514 kc. Armor is 3 cm of boron. LaserModule 1.000 GW Nd:YAG Green Laser ArcLamp GasComposition Krypton EnvelopeComposition Fused Quartz PowerSupplied_W 1e+009 Radius_m 0.01 CavityWallComposition Silver CavityCoolantComposition Hydrogen CavitySemimajorAxis_m 1 CavitySemiminorAxis_m 0.99 GainMedium Nd:YAG OpticalNodes 7000000 LasingRodRadius_m 0.014 Mirror Composition Silver OutputCoupler Composition Fused Quartz CoolantTurbopump Composition Boron PumpRadius_m 0.9 RotationalSpeed_RPM 460 CoolantInletTemperature_K 1200 FrequencyDoubler NonlinearOptic Composition Silver Gallium Selenide OpticLength_m 0.026 OpticRadius_m 0.025 ApertureRadius_m 2.4 FocusingMirror Composition Silver Turret InnerRadius_m 5.1 ArmorComposition Boron ArmorThickness_m 0.03 ReactionWheels Composition Lead RotationalSpeed_RPM 72 EngagementRange_km 250 TargetsShips true TargetsShots true
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foof
New Member
Posts: 31
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Post by foof on Oct 7, 2016 16:22:47 GMT
Hi everyone, I found this article on pump cavity geometry, it says that: But what if they don't have the same diameter? I can calculate the focal points via F =√j2−n2 where: F is the distance from each focus to the center j is the semi-major axis (major radius) n is the semi-minor axis (minor radius) Link: Calculator.But that works only for point sources. I found this But I have no idea how to turn this into a formula where I can insert lamp and rod diameter and get semi major and minor axis as output. Any ideas?
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Lasers
Oct 7, 2016 16:36:09 GMT
Post by blothorn on Oct 7, 2016 16:36:09 GMT
Of curiousity, are people actually using these near-zero-armor turrets in combat? I would expect them to be extremely vulnerable to countersniping.
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Lasers
Oct 7, 2016 17:42:53 GMT
Post by leerooooooy on Oct 7, 2016 17:42:53 GMT
By the way, here's the current version of my 1GW superlaser. Intensity at 240km is 1240 MW/m 2, mass is 46.9 t, and cost is 514 kc. Armor is 3 cm of boron. LaserModule 1.000 GW Nd:YAG Green Laser ArcLamp GasComposition Krypton EnvelopeComposition Fused Quartz PowerSupplied_W 1e+009 Radius_m 0.01 CavityWallComposition Silver CavityCoolantComposition Hydrogen CavitySemimajorAxis_m 1 CavitySemiminorAxis_m 0.99 GainMedium Nd:YAG OpticalNodes 7000000 LasingRodRadius_m 0.014 Mirror Composition Silver OutputCoupler Composition Fused Quartz CoolantTurbopump Composition Boron PumpRadius_m 0.9 RotationalSpeed_RPM 460 CoolantInletTemperature_K 1200 FrequencyDoubler NonlinearOptic Composition Silver Gallium Selenide OpticLength_m 0.026 OpticRadius_m 0.025 ApertureRadius_m 2.4 FocusingMirror Composition Silver Turret InnerRadius_m 5.1 ArmorComposition Boron ArmorThickness_m 0.03 ReactionWheels Composition Lead RotationalSpeed_RPM 72 EngagementRange_km 250 TargetsShips true TargetsShots true
You 100 MW design is a fantastic improvement, but this one might have a few flaws. The mass breakdown is 50% boron armour, 45% lead reaction wheels, 5% other stuff, and the cost breakdown is 70% boron 20% lead. Cutting down on armour allows a switch to lithium reaction wheels, which are stupidly cheap and lightweight. Using lithium and keeping the armour results in minuscule rotation speed (2-3 degrees per second) which might be acceptable considering the range this thing should work at, and basically halves the weight. I am going to try 4mm of amorphous carbon and 100rpm lithium, let's hope it fares well Of curiousity, are people actually using these near-zero-armor turrets in combat? I would expect them to be extremely vulnerable to countersniping. Yes, and they work if backed by proper tactics. The idea is annihilating the enemy weapons before they even have a chance to fire, so you set "ignore range", focus all weapon subsystems, and go for low speed intercepts. That works really well vs AI (again, gold on Vesta with a single ship and near zero effort) , and would probably be effective against an unprepared human opponent too. The big counters would be: - More/more armored lasers, to countersnipe: the first one that takes out all the enemy's lasers would have a nice advantage. Big issue, armor on big lasers is easily 5 times the weight of the laser itself and forces to use heavier reactions wheels, often those weight more than the laser too. So 5-7 lasers are usually going to be cheaper, lighter and even more effective than a single armored counterpart. That goes double since power generation is almost a non-issue because of cheap, lightweight 2200K reactors. Taking out the radiators with lasers is nigh impossible at long ranges, since the heat will just be radiated away, and unsurprisingly the radiator will be able to do that for longer than your turret.
- Spamming kinetic weaponry, ignoring max range. Unless you exploit those Mm/s broken guns and get lucky, not happening. Even a 10 km/s bullet will take 20 seconds to reach the target, most of your weapons will be already fried by then and the enemy could just move sideways to easily dodge the burst at 200+km.
- Nukes. If detonated manually (the default ends up in them slamming into the hull and deactivating a bit too often, or deactivating 90% of the swarm instead of detonating simultaneously) they are the ultimate weapon in general. Cheap, powerful, easily protected, they will burn radiators, light armour, unprotected modules, and will often get crew wipes if placed well. Setting up intercepts manually is a pain tho.
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Lasers
Oct 7, 2016 18:02:04 GMT
via mobile
Post by ross128 on Oct 7, 2016 18:02:04 GMT
Gyrojets are also a pretty good counter to laser sniping because the approaching missiles will kick the lasers into point-defense mode, which means they are no longer targeting your ships. As long as the cannons can spit out micro-missiles faster than the lasers can pop them, the enemy will be unable to target you and the missiles will eventually kill them.
The missiles home in on the radiator section though, so it doesn't change the fact that the only armor laser turrets need is a thin layer of basalt fiber (because they can't use silica aerogel) to delay enemy lasers.
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Post by apophys on Oct 7, 2016 18:06:00 GMT
Wait a minute... 1.01 GW and 71 MW? Those must be my reactors! Glad they're seeing use. Your 100 MW design is a fantastic improvement, but this one might have a few flaws. The mass breakdown is 50% boron armour, 45% lead reaction wheels, 5% other stuff, and the cost breakdown is 70% boron 20% lead. Cutting down on armour allows a switch to lithium reaction wheels, which are stupidly cheap and lightweight. Using lithium and keeping the armour results in minuscule rotation speed (2-3 degrees per second) which might be acceptable considering the range this thing should work at, and basically halves the weight. I am going to try 4mm of amorphous carbon and 100rpm lithium, let's hope it fares well My thought process justifying it is as follows. You can swap boron to UHMWPE and wheels to cadmium fairly easily; this results in a bit over 30t weight. But the cost skyrockets due to 3cm of UHMWPE (may or may not be worth it, but I'm stingy). Lighter reaction wheels while leaving the armor alone require far higher power to sustain at this targeting speed. Your preferred power balance may differ, and you may accept a lower speed. I'm uncomfortable lowering the armor on the turret further than this, since it represents a pretty sizable investment on the ship (1GW of reactor, plus assorted radiators for both reactor and laser, plus ship armor wrapping the reactor, plus dV to move all this). The weight is already 50% lighter than an equivalent 10 of my 100MW lasers, while having more power and higher intensity than such a collective.
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Lasers
Oct 7, 2016 18:45:42 GMT
Post by captinjoehenry on Oct 7, 2016 18:45:42 GMT
One thing that you need to keep in mind with lasers is that they are childishly easy to protect against. If you just have some aerogel or basalt fiber outer coat for your armor lasers just stop being useful. And if you provide your turrets with a thin coat of basalt fiber or heck a thick coat it'll be fairly lightweight and nearly impervious to all lasers. And it turns out spamming flack warheads or nuke warheads from a coil gun is really effective along with missiles. And it is easy to protect projectiles and missiles from lasers with the same type of armor.
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