This is the first blog post I am making on Vivaldi, and I hope you enjoy this new blog!.
I hope this photo gets your attention. I don’t recall where it came from, so I can’t provide proper attribution. I greatly admired the pilot’s skill. He must have been steering that BUFF by using the cross-wind crab control on the landing gear.
I was pleased today to hear that the U.S. Navy is about to field a shipboard laser weapon constructed by coupling a number of solid-state lasers together. On the other hand, I was saddened that the U.S. Senate cut off funding to the Navy’s Jefferson Lab that might have seen the Free-Electron Laser (FEL) and the General Atomics railgun brought to completion. The Air Force would be wise to take over the development of the FEL, if it isn’t working on its own version.
To quote from a paper by researchers from the Lab, “An airborne megawatt (MW) average power Free-Electron Laser (FEL) is now a possibility. In the process of shrinking the FEL parameters to fit on ship, a surprisingly lightweight and compact design has been achieved. There are multiple motivations for using a FEL for a high-power airborne system for Defense and Security:
• Diverse mission requirements can be met by a single system.
• The MW of light can be made available with any time structure for time periods from microseconds to hours, i.e. there is a nearly unlimited magazine.
• The wavelength of the light can be chosen to be from the far infrared (IR) to the near ultraviolet (UV) thereby best meeting mission requirements.
• The FEL light can be modulated for detecting the same pattern in the small fraction of light reflected from the target resulting in greatly enhanced targeting control.
The entire MW class FEL including all of its subsystems can be carried by large commercial size airplanes or on an airship. Adequate electrical power can be generated on the plane or airship to run the FEL as long as the plane or airship has fuel to fly. The light from the FEL will work well with relay mirror systems. The required R&D to achieve the MW level is well understood. The coupling of the capabilities of an airborne FEL to diverse mission requirements provides unique opportunities.”
The best thing about the FEL is that it does not need chemicals to generate light, and if mounted on a B-52, would diminish or eliminate the need to rush the ‘Next Generation Bomber’ into production. Think of the time and money savings. Think of the new lease on life for the BUFF. Think of the terror it would instill in our enemies as it takes out any airborne weapon they might launch at it. Think of the fact that the BUFF was designed for high altitude flight, not sneaking in under the radar or requiring a fighter escort.
BUFF would mean Big Ugly Flying Fortress? Pretty cool, if you ask me. Can you imagine the looks of the faces of the troops on the ground? :yikes:
Glad to see you, David! 😀
Thanks, Dennis!
I haven’t figured out the ins & outs of Vivaldi yet, but I’m trying. You are offering a kinder version of the term BUFF, which really is: Big, Ugly, Fat, F***er!
Ah! That was my second choice.
About Vivaldi, there’s a lot of potential here. I’d consider this an alpha version. I personally am having issues with rendering, and the on screen keyboard on my new phone.
Hope things are reasonably good with you and yours.
Same to you Dennis! 🙂
I wonder how hot the interior of a plane will become when a megawatt laser fires. Even the best LASERs nowadays have only an efficiency of about 30%, meaning they have to get rid of 70% of the input energy as waste heat. Now imagine 3MW output LASER in a relatively small confined space like a plane – it will be equivalent to heater with 7 megawatt waste heat radiation, a literally hot weapon …
hint: You need only about 1MW to heat up a volume of 10000m³ (13000 yd³) to 100°C (212°F) – and the B52 is way smaller …
Hey David, WELCOME. Thought you’d never get here….LOL.
Interesting post as usual. Never did understand their technology, so can’t say much about it, but I do learn from posts that are made about technology.
Hope to see you around here more often. I know it won’t be as much as Opera, but I know it will be often.
Kim
Hi, Roland; thanks for the visit to my new blog. I can see where you would think thermodynamics would be an issue, but consider this: Flying at say, 60,000 feet, the B-52 equipped with a one Megawatt FEL laser could take out 6-8 main battle tanks in a column on the ground in about two seconds. At that altitude, cold air is abundant for recirculation in the laser. Also, time-on-target is short and even at low altitude, this could easily be handled, especially when only certain components are subject to a short-term thermal excursion.
Hi, Kim; Nice to see you here as well!
Hi David, welcome. I’m so glad you decided to come here.
I subscribed to your blog.
😀
18km (60,000 feet) is a hell of distance to focus a laser that sharp, that it can manage a penetration in short time.
1MW*s output divided by 4 would be 250 kilojoule per tank – which is way less than e.g. the energy of a 120mm canon with a punch of 9,8 megajoule and even those often do not take out a major battle tank like the newest incarnations of the M2 or the Leopard. Even metal fumes disperse the laser rapidly, so I’d say that the time in the target needs to be longer.
And yes, you are right, -50°C (-58°F) air with some hundred km/h provides A LOT of cooling, but the problem is, that the heat has to dissipate through the components before it can be carried away – and this leads to very high peaks inside of the material. I wonder for how many “shots” the FEL will last …
But it is still fiction, because if my sources are correct, the Raytheon contract is for a 100 kW FEL atm and the new improved designs for naval use by Boeing Directed Energy Systems will not be ready before 2018 – the prototype, that is …
Hi, Roland, you seem to be well informed, but you assume the beam is split into four beams before engaging the targets. Actually, the beam moves from point A to B to C, etc. in that short interval of time, addressing each target with full beam power. Also, the beam is not laser light in the conventional sense; it is my understanding that it is an intense stream of Electrons. See this informative PDF file: http://www.stfc.ac.uk/ASTeC/Resources/PDF/Thompson_FELs.pdf
100kw is the minimum goal for a Star Wars beam weapon, but 20 Kilowatts works pretty well on a lot of targets like the drug runner’s boat featured in a video released by the U.S. Navy.
With regard to the state of development, recall that Stealth aircraft were used in Panama to unseat Noriega long before any public release of the technology. 🙂
Here is an update to my post from Ed Jackson at the Air Force Association:
“That picture was a B-52H that got caught in mountain wave while flying low level through the Rockie Mountains. There was a Boeing flight test crew flying the airplane, not a SAC crew. The airplane was able to make a recovery at Blytheville AFB, AR (later called Eaker AFB) sometime in the mid 1960s. That bomber was later repaired and rejoined the SAC fleet.
But the problem of a shipborne or airborne FEL laser is it is effected by atmospheric conditions, therefore its range is limited by the prevailing weather conditions. Chemical lasers are much more reliable for long range beam projection. That is why the test bed YAL-1A, a Boeing B-747-400F, was equipped with a chemical laser. The Navy plans to use their FEL laser for ship defense against attacking aircraft, missiles, and small boats.”
Not necessarily. MW is power but it says nothing about the energy that hits the target and to destroy a target, you need a certain power for a certain time – aka power multiplied by time. You can cut with the 20mW LASER of a blu-ray burner through a tank, provided you have a good focus and enough time (a week? :D)
Normally the energy for such applications is measured in Ws or J. I assumed a sustained beam power of 1 Megawatt for a second (i.e. 1 MWs = 1MJ), which results in 250kJ per target, if you hit 4 targets during one second. The energy amount is independent of splitting the beam into four and hitting with four weaker beams at the same time for one second or using the full beam but dividing the in-target time by four.
And no, it is not an electron beam, that would not reach that far in free air and would not scratch a tank much more than if it would be, if it were hit by a natural flash of lightning during a thunderstorm (which is magnitudes more powerful) – but sadly tanks are basically Faraday cages and as such not very impressed by electrons.
The emitted energy of the FEL is in principle synchrotron radiation of a “not correctly” tuned undulating particle accelerator (a correctly tuned would emit no light) and the result is simply light. If it were electrons they would have vast problems with the positive ions that would be left over (aka highly reactive plasma) which would have a devastating effect on the whole “LASER”. Strictly speaking a FEL is no LASER, but a highly brilliant and coherent light source. Sounds like the description of light emitted by a laser but the way it is produced is different. There is no stimulated amplification by light, but emission of excess energy of high speed electrons caused by changing magnetic fields. The excess and out of phase energy is emitted as light which only happens to have the same properties as light emitted by a LASER. (Yeah, that sounds like eggheaded nitpicking, but it is important to distinguish between those two. Physics is always about details, even if the military does not care how the punch is generated :D)
And yes, you don’t need that much power if you want to punch tiny holes, which are perfectly fine too. Imagine what a 8mm (0.3″) hole through a motor block would do to it 😉
BTW:
Rheinmetall built some working FEL prototypes with 50kW (superimposed 20+30kw modular system) output power in 2012 and tested them successfully:
http://www.rheinmetall-defence.de/en/rheinmetall_defence/public_relations/news/archive_2012/aktuellesdetailansicht_4_2368.php
The FEL is only effected by atmospheric conditions if the frequency of the light is not chosen well – and that is one of the big advantages of a FEL: It can be tuned to work from infrared to X-ray.
The Rheinmetall tests in 2012 and 13 showed that it can work perfectly well even when it is snowing, if the frequency is adapted to the conditions.
BTW: Mountain wave? Is that the lee wave behind a mountain? (No native English speaker here)
If yes: I have heard that there are some very nasty rolling waves in the Rocky Mountains. I wonder that it didn’t crash the whole plane, the pilots must have done a hell of a job when it hit them. Flying in smooth air without vertical tail is actually not that hard, but I can imagine that it is a PITA when you are hit by wind shear or while in ground effect during the landing phase…
Hi, Roland, yes, very nasty waves in the Rocky Mountains. Flying in that wounded bird would be a Pucker Factor 10! By the way, are you a Physicist working in directed energy? Where in Germany are you located? I did a bit of consulting work at the University of Heidelberg, and love the country. Munich is one of my favorite places.
Nope, no physicist, only a good old fashioned “Diplomingenieur” (similar to todays masters degree but a bit more expanded) of electrical communication engineering which included 2 years of hardcore physics at my time. I had the luck to be in the courses of one of the best German high energy particle physicists, who was involved in DESY and CERN at that time. Not that it helped that much in the end, I forgot most of it during the last decades – but I still can understand what the written squiggles of the physicists mean, when they are describing something 😀
btw: While Munich is a nice city for an occasional visit, I prefer the northern regions of our country – no “Dirndl” and “Lederhosen” there, you know 😉
A final remark: The ultimate Directed Energy weapon is the particle beam. This work is so classified, I have no idea what the level of technology is.
Thanks, Carol–I almost missed your comment here–sorry….:)
You are welcome David. 🙂
I know what you mean. I am still not use to navigating around here yet.