The Active Denial System: What Is It And What Does It Do?

The active denial system is a non-lethal, directed-energy, counter-personnel weapon system owned by the US military. It consists of a gyrotron, which generates and focuses a high-energy millimeter-wave radio frequency beam (a type of electromagnetic radiation) onto a target to provide a very hot, skin surface-burning sensation.

I was recently watching a war film set during World War 2. It obviously featured a lot of weapons that were actually used on battlefields during the war. One of those weapons was a ‘flame thrower’. As the name clearly signifies, it was a gun that spewed fire instead of bullets.

The flame throwers

Flame throwers were widely used by all participating countries during the second world war.

Although it could also be (and was) used in a direct assault on the enemy, it was primarily used to destroy bunkers and clear out hostile areas by setting them ablaze.

Fast forward 70 years and those flame throwers have virtually disappeared from the theatre of war. They might have been effective back then, but today, they are replaced by far more sophisticated, sturdier and powerful weapon systems.

Although there are numerous modern weapons that are infinitely more technologically advanced than their predecessors, the specialty of the one we are going to talk about in this article is that it creates a strong burning sensation in its targets without igniting a fire. Plus, it’s absolutely non-lethal!

The Active Denial System

The active denial system is a directed-energy weapon system designed and developed by the US military. Also known as the ‘heat ray’ or ‘pain ray’ by some, it is a non-lethal weapon system designed for perimeter security and crowd control.


The V-MADS atop a Humvee (Photo Credit : Airman st Class Gina Chiaverotti / Air combat command)

Commonly abbreviated as the ADS, the active denial system is currently only a vehicle-mounted weapon, meaning that it can only be used from a designated vehicle and is not portable, as of now (that’s the reason it is sometimes also referred to as the V-MADS, i.e., the Vehicle-Mounted Active Denial System). It emits a man-sized beam of millimeter waves (a type of electromagnetic radiation), which produces a hot, burning sensation in the skin when it strikes a (human) target.

How does the active denial system work?

The working principle of the active denial system is quite similar to that of a microwave oven. Just as a microwave has a magnetron that emits microwaves and heats up the food kept inside, the V-MADS system consists of a gyrotron that emits millimeter waves at a frequency of 95 GHz down range with the help of a reflector.

These waves travel at the speed of light (since they’re part of the electromagnetic spectrum) to hit their target. When the focused high-energy beam strikes the target (say, a human), it interacts with the tiny water molecules (or moisture) present on its surface and excites them, producing an unnerving – but non-lethal sensation – of intense heat.

Although the working principle of the V-MADS is quite similar to a microwave oven, it’s actually significantly different from everyone’s favorite home appliance.

For instance, a microwave employs waves that have a frequency of 2.45 GHz, whereas V-MADS operates at a much higher frequency of 95 GHz. This means that the associated wavelength of these waves is very short and, as such, can only penetrate 1/64th of an inch. Microwaves, on the other hand, can roast a food item from the inside out!

Is the Active Denial System dangerous?

The ADS is known for its ability to briefly and intensely heat the topmost surface of the skin without actually harming the human target. In most cases, therefore, it’s not found to be harmful to the exposed individual. In fact, that characteristic, along with its long range, makes it a very effective non-lethal weapon.

The effects of the ADS have been tested by conducting studies spanning more than 15 years and involving more than 13,000 exposures from volunteers. According to the US’ Non-lethal Weapons program, the use of V-MADS on individuals demonstrates a minimal risk of injury and high effectiveness.

Although adverse reactions are quite rare, exposure to these types of high-energy beam may cause blisters in certain victims. Some studies also suggest that the long-term effects of V-MADS exposure may lead to cancer or even death (Source).


  1. College of William & Mary – Public university in Williamsburg, Virginia
  2. Duke University School of Law
  3. Pennsylvania State University
  4. United States Department of Defense
  5. United States Department of Defense (research findings)
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About the Author:

Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spends a lot of time watching movies, and an awful lot more time discussing them. He likes Harry Potter and the Avengers, and obsesses over how thoroughly Science dictates every aspect of life… in this universe, at least.

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