US fires up crowd-roasting microwave gun
'Less than lethal' Silent Guardian unveiled
The US military has finally rolled out its Silent Guardian - a 95GHz millimetre wave "active denial system" designed to "repel individuals or crowds without causing injury".
The weapon - mounted atop a Humvee - reportedly has a range of 500 metres within which it heats its targets' skin to 50°C. According to the BBC, journalists who voluntarily put themselves in the firing line during a demonstration at an air base in Georgia, "described the sensation as similar to a blast from a very hot oven - too painful to bear and forcing them to dive for cover".
Manufacturer Raytheon describes  the Silent Guardian thus:
The Silent Guardian™ protection system is a revolutionary less-than-lethal directed energy application that employs millimetre wave technology to repel individuals or crowds without causing injury. The system provides a zone of protection that saves lives, protects assets and minimises collateral damage. Silent Guardian produces precise effects at longer ranges than current less-than-lethal systems and provides real-time ability to establish intent and de-escalate aggression. Various commercial and military applications include law enforcement, checkpoint security, facility protection, force protection and peacekeeping missions. The system is available now and ready for action.
The company's cut-out-and-keep guide  elaborates:
The system's antenna emits a focused beam of millimeter wave energy. The beam travels at the speed of light and penetrates the skin to a depth of 1/64 of an inch, producing an intolerable heating sensation that causes the targeted individuals to instinctively flee or take cover. The sensation ceases immediately when an individual moves out of the beam or the operator steers the beam away. Silent Guardian does not cause injury because of the shallow penetration depth of the millimetre wave.
The US military originally planned to deploy the Silent Guardian in Iraq by the end of 2005, having ordered 15 examples under "Project Sheriff". Delays to its roll-out were reportedly due in part to developing a sufficiently strong power source to fire up the beast. ®