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67-Kilowatt Laser Unveiled
s31523 writes "Lawrence Livermore National Laboratory in California has announced they have working in the lab a Solid State Heat Capacity Laser that averages 67 kW. It is being developed for the military. The chief scientist Dr. Yamamoto is quoted: 'I know of no other solid state laser that has achieved 67 kW of average output power.' Although many lasers have peaked at higher capacities, getting the average sustained power to remain high is the tricky part. The article says that hitting the 100-kW level, at which point it would become interesting as a battlefield weapon, could be less than a year away."
Let me guess -- the Pentagon now has everything it needs to proceed with the Death Star?
The article does not mention that any reflection off whatever the laser is aiming at is many kW as well. A small polished piece of steel would reflect 80% in some random direction, and the beam will go until it reaches something. Only a few milli Watts would be sufficient to damage the eyes of civilian spectators, so a reflection could easily permanently blind everyone in a football stadium of 50000 people.
"Fix it"
If your mirror is 99% reflective (which would be very, very good -- and it won't stay that way in a dusty dirty battlefield), you'd still be absorbing 1kW of power. Which might be very easy or very hard to dissipate, depending on the beam diameter and how well the targeting system can keep it on the same piece of armor. And, as soon as your armor starts to heat up more than a little, the reflectivity will drop and it will fail.
Everyone always thinks mirrors are an easy answer to laser weapons, but it's not really that simple; sure they're worth considering, but they're not obviously a winning strategy.
A better armor might actually be an ablative -- eg a phenolic or graphite plate that absorbs all the heat at the very surface, and vaporizes into a cloud of gas that then takes the majority of the heating while the armor continues ablating from conducted heat and laser heating that gets through -- meanwhile the targeting system frantically tries to keep the laser on the same spot long enough to punch all the way through, and the tank driver tries to conduct evasive action. Modern ablative technology for rocket engines can take 1kW/cm^2 of heating and last for minutes of service; ablatives derived from such technologies might make very effective armors.
Insightful how? Making mirrors that can withstand 100+kW of energy you can't exactly go down to your hardware store. Insurgents have nowhere near the facilities or technology to create anything close to withstanding 100kW.
Your hair look like poop, Bob! - Wanker.
there is little to no physical force behind it; the destructive energy is heat. Things won't explode like they do in Star Wars and other sci fi/fantasy movies and shows.
The satellite-based lasers for Star Wars (Reagan's wet dream, not the Movie) primarily worked by kinetic activity.
A cutting laser doesn't take anywhere near 67kW, but they work fairly slowly (slow enough for an armored target to take countermeasures). Instead, you want to basically vaporize a few nm of the surface, resulting in exactly the sort of explosion you say doesn't happen.
Search Google for "arc flash"... Though a much more mundane effect, it gives the general idea... Basically, if you vaporize copper bus bar by shorting it out, it produces a pretty impressive "explosion" due to the copper suddenly occupying 67,000 (no connection to the laser from the FP, just a coincidence) times its original volume.