Active Denial System - Effects

Effects

The ADS works by firing a high-powered beam of 95 GHz extremely high frequency waves at a target, which corresponds to a wavelength of 3.2 mm. The ADS millimeter wave energy works on a similar principle as a microwave oven, exciting the water and fat molecules in the skin, and instantly heating them via dielectric heating. One significant difference is that a microwave oven uses the much lower frequency (and longer wavelength) of 2.45 GHz. The short millimeter waves used in ADS only penetrate the top layers of skin, with most of the energy being absorbed within 0.4 mm (1/64"), whereas microwaves will penetrate into human tissue about 17mm (0.67").

The ADSʼs repel effect in humans occurs at slightly higher than 44°C (111°F), with first-degree burns occurring at about 51°C (124°F), and second-degree burns occurring at about 58°C (136°F). In testing, pea-sized blisters have been observed in less than 0.1% of ADS exposures, indicating that second degree surface burns have been caused by the device. The radiation burns caused are similar to microwave burns, but only on the skin surface due to the decreased penetration of shorter millimeter waves. The surface temperature of a target will continue to rise so long as the beam is applied, at a rate dictated by the target's material and distance from the transmitter, along with the beam's frequency and power level set by the operator. Most human test subjects reached their pain threshold within 3 seconds, and none could endure more than 5 seconds.

A spokesman for the Air Force Research Laboratory described his experience as a test subject for the system:

"For the first millisecond, it just felt like the skin was warming up. Then it got warmer and warmer and you felt like it was on fire.... As soon as you're away from that beam your skin returns to normal and there is no pain."

Like all focused energy, the beam will irradiate all matter in the targeted area, including everything beyond/behind it that is not shielded, with no possible discrimination between individuals, objects or materials. Anyone incapable of leaving the target area (e.g., physically handicapped, infants, incapacitated, trapped, etc) would continue to receive radiation until the operator turned off the beam. Reflective materials such as aluminium cooking foil should reflect this radiation and could be used to make clothing that would be protective against this radiation.

Many human tests have been performed on over 700 volunteers and including over 10,000 exposures by ADS. A Penn State Human Effects Advisory Panel (HEAP) concluded that ADS is a non-lethal weapon that has a high probability of effectiveness with a low probability of injury

• no significant effects for wearers of contact lenses or other eyewear (including night vision goggles)
• normal skin applications, such as cosmetics, have little effect on ADSʼs interaction with skin
• no age-related differences in response to ADS exposures
• no effect on the male reproduction system
• the limit of damage was the occurrence of pea-sized blisters in less than 0.1% of the exposures (6 of 10,000 exposures).

In April 2007, one airman in an ADS test was overdosed and received second-degree burns on both legs, and was treated in a hospital for two days. There was also one laboratory accident in 1999 that resulted in a small second-degree burn.