E-BLAST: The simplest kind of electromagnetic-pulse source works by blowing itself up.
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By Sharon Weinberger of Nature magazine
For some Pentagon officials, the demonstration in October 2007 must have seemed like a dream come true — an opportunity to blast reporters with a beam of energy that causes searing pain.
The event in Quantico, Virginia, was to be a rare public showing for the US Air Force's Active Denial System: a prototype non-lethal crowd-control weapon that emits a beam of microwaves at 95 gigahertz. Radiation at that frequency penetrates less than half a millimeter into the skin, so the beam was supposed to deliver an intense burning sensation to anyone in its path, forcing them to move away, but without, in theory, causing permanent damage.
However, the day of the test was cold and rainy. The water droplets in the air did what moisture always does: they absorbed the microwaves. And when some of the reporters volunteered to expose themselves to the attenuated beam, they found that on such a raw day, the warmth was very pleasant.
A demonstration of the system on a sunny day this March proved more successful. But that hasn't changed a fundamental reality for the Pentagon's only acknowledged, fully developed high-power microwave (HPM) weapon: no one seems to want it. Although the Active Denial System works (mostly) as advertised, its massive size, energy consumption and technical complexity make it effectively unusable on the battlefield.
The story is much the same in other areas of HPM weapons development, which began as an East–West technology race nearly 50 years ago. In the United States, where spending on electromagnetic weapons is down from cold-war levels, but remains at some US$47 million per year, progress is elusive. “There's lots of smoke and mirrors,” says Peter Zimmerman, an emeritus nuclear physicist at King's College London and former chief scientist of the US Arms Control and Disarmament Agency in Washington DC. Although future research may yield scientific progress, he adds, “I cannot see they will build a useful, deployable weapon”.
For many critics, the US HPM program has become a study in wishful thinking, exacerbated by a culture of secrecy that makes real progress even more difficult.
The quest to build an electromagnetic weapon — an e-bomb, in military jargon — was sparked on 8 July 1962, when the United States carried out Starfish Prime, the largest high-altitude nuclear test that had ever been attempted. The 1.4-megaton thermonuclear warhead, detonated 400 kilometers above the central Pacific Ocean at 9 seconds past 11 p.m., Hawaii time, blasted huge swarms of charged particles outwards along Earth's magnetic field. Their gyrations generated a pulse of microwave energy that drove measuring instruments off the scale. Artificial auroras lit up the night across swathes of ocean. And in Honolulu, more than 1,300 kilometers from the detonation point, the pulse set off burglar alarms, knocked out street lights and tripped power-line circuit breakers.
Nothing like Starfish Prime has been seen since August 1963, when the Partial Test Ban Treaty outlawed nuclear explosions anywhere but underground. But the test showcased the potential destructiveness of an electromagnetic pulse to military planners on both sides of the cold-war divide, and launched them into a race to harness it as a weapon using a non-nuclear source.
Power cut
The US Air Force has been the main funder of the country's HPM program from the beginning. At first, its goal was a weapon capable of taking out an enemy's computers, communication systems and other electronics. In theory, the idea remains compelling: an e-bomb would be able to fire microwave 'bullets' at the speed of light and, if tuned to the right frequencies, disable its targets without collateral damage. Cars could be stopped in their tracks, radars blinded and computers destroyed, with no need for high explosives.
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Reply | Report Abuse | Link to thisIronic isn't it? Just last month you had a news blurb right in your own magazine about some physicists who sucessfully produced a MASER using a Laser pumping system I believe. Wasn't the article something like, "First Practical Maser (Microwave Laser) Is Built". Look it up with the search option on the term MASER. Maybe sometimes pre-conceptions can get in the way of innovation? Of course, there's a long way to go yet.
Reply | Report Abuse | Link to thisI definitely feel it would be worth having somethings like those weapons and am in favour to carry on with the research. New ideas and materials might bring solutions. I saw a picture of the first cavity magnetron, it was as big as a desk. A few months later they made them small enough to fit them into 1940 era fighter planes.
Reply | Report Abuse | Link to thisWow - the "Active Denial System" - how appropriate!
Reply | Report Abuse | Link to thisOn a clear day (with low atmospheric humidity) this technology might be considered threatening. What with global warming, will the future effectiveness of such weapons be increased or decreased?
Yes, by all means, lets fund some more of these stories - they're priceless!
Right, but a MASER generates a focused, coherent electromagnetic beam (not necessarily microwaves), whereas this article implies that we are looking for more of an area or theater capability and a globular radiative path.
Reply | Report Abuse | Link to thisI don't believe that we are talking about the same concept.
Yes, my point was (at least I intended it to be) that the military view of a MASER as a "weapons system" blinded them to any "out of the box" innovative thinking. That fact (and the fact that any military research has basically been classified for 50 years) has basically stopped any research on possible other uses and advances in MASER technology. Look at that Scientific American article I mentioned in my previous post. It appeared on 16 August 2012.
Reply | Report Abuse | Link to thisThe advances mentioned in that 16 August article are:
1. The entire apparatus sits easily on a tabletop.
2. It operates at room temperature. No extreme low temperature cooling required.
3. It produces a coherent directed beam of microwave radiation at what is still a relitivly low power...but nearly a million times higher than any other Maser before.
The difference in results, in my opinion, is that this new research was simply done to see if the idea worked, all the previous military reaserach was to make a weapon.
They simply ignored anything that didn't "look like" a weapon. That pre-conception made them blind to other possible uses of a low power Maser.
Or as the saying goes, "When all you want to do is break rocks, everything looks like a hammer to you."
Nicely put, but as I recall the correct saying (one of my favorites) is: 'To a man whose only tool is a hammer, every problem appears to be a nail'.
Reply | Report Abuse | Link to thisHowever, that one doesn't quite fit here...
If they want a tactical area weapon, what is wrong with simple microwave sources from a few microwave ovens being grouped together with 1 side unshielded and run by battery? I'm not saying it would be small or low power but it should be unpleasant.
Reply | Report Abuse | Link to thisThe FBI stole N. Tesla's papers upon his death; they've remained hidden since the 1940's. Tesla, of course, had invented a "Death Ray" useful to, perhaps, being a winning game-changer in WW-2, Korea, Vietnam, and a few other conflicts. Where are Tesla's papers today?
Reply | Report Abuse | Link to this«Despite 50 years of research on high-power microwaves, the U.S. military has yet to produce a usable weapon» I found the above news extremely encouraging. Perhaps one day we will learn to devote our intellectual and economic capital to something more rewarding (if less profitable for some) than attempting to find new ways to kill or otherwise incapacitate people....
Reply | Report Abuse | Link to thisHenri