As and engineer and founder of an EMP protection startup company , I wanted to explain some EMP basics and also educate readers about current Directed Energy Weapons (DEW.)
Qualifications: My team has developed the first EMP simulator-tested laptop EMP shield that lets you protect and use your laptop (including wireless.) So, over the past year, we’ve learned firsthand what’s true and what’s not regarding radio frequencies. All subjects mentioned are the opinion of MobileSec Solutions LLC but not legally binding.
General Overview
Electromagnetic pulse (EMP) is generated usually when a nuclear device is detonated in the upper atmosphere. Non-nuclear explosive devices work too but on a smaller scale; even a transformer exploding, as in the movie Small Soldiers, generates a localized pulse. EMP is comprised of the fast rise-time E1 component, the lightning-type E2 component, and the solar flare type E3 component. Different things are vulnerable to different components of EMP, so let’s cover what you actually need to know.
The most important concept is wave physics, or the frequency and wavelengths of the EMP waves. Basic physics teaches that higher frequencies equal shorter wavelengths. If a wavelength is larger than the opening, it is blocked. So smaller wavelengths need smaller openings for a blocking material to work. Therefore, in general, if we block high frequencies, we probably block low ones too. In practice, shielding effectiveness does not always work this way, but this is a “good enough” explanation.
An EMP generates a broad band of waves ranging as high as 10 gHz (gigahertz). Our focus is on preventing damage in the range of roughly 200 mHz – 1 gHz, mostly the domain of E1. Above 1 gHz, it becomes increasingly more difficult to create damaging waves, although theoretically possible. As wavelength decreases (and frequency increases), eventually you get into microwave territory, so the shell of a solid object starts to absorb the energy, not the interior electronics. Of course, slightly heating a laptop frame cannot damage it. The E2 and E3 components are far lower in frequency, with E3 having such a long wavelength that, as long as your devices are not connected to any large conductive lines (like power lines or antennae), and are small, they should not be damaged by E3.
These facts have enormous implications for the range of the various EMP components. E1 and E2, have much higher frequencies, so they are basically dissipated in the atmosphere by water vapor over a long distance. In other words, for E1 and E2 to be affecting your electronics, your general metro area must have been specifically targeted by an EMP weapon. One cannot make an EMP with an E1 pulse across the entire continent – the power requirement is beyond even nuclear capabilities. However, it IS possible to generate a wide-ranging E3 pulse (due to its much longer wavelength).
Incidentally, this also explains why, if you search the internet, you can see government buildings use 1-inch copper mesh. This hole size is geared towards E3 only. Apparently, the logic is that a nuke would have to be targeted at that specific area in order for the building to be impacted by E1 and E2 (which require MUCH smaller mesh hole sizes, which increase the cost dramatically). That means that particular nuclear device is NOT targeting anywhere else – so short of nuclear war, the loss of any one single facility cannot significantly impact the US. Furthermore, within each E3-shielded building, certain rooms ARE shielded to a much better standard to protect the really mission-critical equipment from E1 and E2. This provides a high level of protection while reducing costs.
Potential EMP Sources
EMP doesn’t correlate with yield – any nuke can generate an EMP, so “rogue states” can do it – and in fact, some have tested missiles apparently optimized for EMP. The sun can generate a massive solar flare E3 pulse too.
Protective Materials
Our testing has shown that the best materials are copper and stainless steel for shielding purposes. Copper is the single best material that is somewhat cost-effective (however, mixed materials, such as silver-coated or copper-coated stainless steel, can perform even better). It is very good for E3, in addition to E1 and E2, but it is also expensive and very fragile. Stainless steel blocks higher wavelength RF energy slightly better and is much stronger and cheaper. Interestingly, aluminum foil works too. With the built-in EMI (electromagnetic interference) shielding inherent in most electronics, using any of these materials is sufficient protection.
Material Configuration
For all practical purposes, material thickness is irrelevant for EMP (almost any available material is thick enough). Solid sheets are the absolute best. However, if visibility is needed, use many small openings (pinholes) in the material versus a few large ones. 100 OPI (openings per inch) balances visibility and protection – we even use it in our products so we can testify to its effectiveness. Above 100 OPI, visibility degrades, and below it, protection decreases. The main issue with protective materials is creating a solid seal around an enclosed object. Your material must contact itself all around. We use magnets sewn inside the mesh material to force a seal. Conductive thread has not been necessary in our tests.
EMP Best Practices
To minimize chances of EMP damaging your electronics, a few basic steps will help a lot. Turn off electronics not in use. Unplug devices that do not need to be plugged in at that time. For your laptop – disconnect cables connected to USB or serial ports, or all ports for that matter. Our testing showed that striking the USB or serial ports – pathways into the electronics of the laptops – made the laptops much more vulnerable. Have a few backups inside Faraday cages (electrical insulation, we’ve found, is actually not very important because the nature of a Faraday cage keeps all the energy on the outside surface of the shield, not the inside. This also means that grounding a Faraday cage is irrelevant – it just bleeds the energy out faster, but since all the energy is on the outside, there’s no damage to your electronics anyway.
To test protective shielding, put a cell phone inside and try to call it. If you can’t, odds are good that your shielding will withstand an EMP. However, it may be the case that you can get a call through (if you are very close to a cell tower) but the shielding is sufficient. EMP can be analogized like a gunshot sound – without protection, your hearing will be damaged. With earmuffs, you can still hear the gunshot, but it’s no longer able to damage your hearing. By the same token, no earmuffs will help you if you are standing next to a main battle tank about to fire – you will feel it. Everything depends on circumstances.
Directed Energy Weapons
We also wanted to talk about some of the newest known tactical energy weapons out there and how to counter them. We will cover the Boeing CHAMP missile, the Active Denial System, Bofors BAE Blackout system, and the recently revealed NATO EMP system.
Boeing CHAMP Missile – This missile is supposed to create a high-powered microwave (HPM) that disrupts electronics within a single target building. Based on the public video footage (available on Boeing’s web site), we believe counters are relatively simple. In the footage, it’s clear that every computer tested was a desktop. The reason for that appears to be that the weapon attacks through the power supply and building wiring In other words, unconnected laptops may well be unaffected . Simply unplugging devices or having better grounding should prevent damage. Additionally, enclosing electronics within a Faraday cage should enhance protection even further. We actually achieved a similar effect, albeit on a smaller scale, while doing our EMP testing and solved it by grounding. Additionally, careful analysis of the footage reveals that many of the computers remain semi-operational even after the strike while being plugged in. It’s possible that the worst damage from this missile could just a simple reset of your electronics.
Active Denial System – This military program is another HPM device, operating on the 95 gigahertz frequency. It generates heat in the 1/64 th inch of your skin, stimulating nerves and creating an instinctive pain signal. Unclassified demonstrations show soldiers having no choice but to flee. But, based on the data provided, we believe it can be countered with a literal aluminum foil shield or other metal shield. As the wave only penetrates the very outer layers of skin, a very thin metal film should be enough to counter this weapon. Additionally, this system reportedly works only in clear weather – rain or fog apparently reduces the weapon’s effectiveness to merely being a nice warm feeling. A metal shield to block the microwaves, or even a body of water, should reduce this threat significantly.
Bofors BAE Blackout – Not much is known about this device. The range is reportedly relatively high – up to a few hundred meters – but the machine is bulky. It operates on the L-S radio wave bands. Therefore, we believe that a shield made out of stainless steel, or copper, with relatively small holes (100 OPI) should prevent damage to enclosed devices. Again, aluminum foil can be used too.
NATO EMP – This device was unveiled recently – it just made the news within the past two months. It is a vehicle-mountable device that stops cars by interfering with the electronic control systems. It’s touted as a way to safely shut down speeding cars (to prevent car bombs at checkpoints). The issue we see is that, given that it does not destroy the electronics of the cars, the strength of the wave transmitted cannot be very high. In other words, it should be relatively easy to, again, use a metal mesh material or aluminum foil to reduce the effectiveness of the device.
As you can see, the major directed energy weapons that are being touted as “next generation” are generally not a material threat – assuming you have done some basic preparations.
The Real Threat
In our opinion, most of the threat of current known EMP is overblown.
However, there are two major sources of very serious EMP threats. The first is the rumors of classified EMP weapons. If these weapons exist and can in fact generate significant E1 and E2 over large regions, they are a major threat. Additionally, if these weapons can generate up to 300,000 volts/meter (50,000 volts/m is the limit for military testing as per RS-105) as claimed, they can become catastrophic events. EMP shielding your electronics is critical. As a side note, EMP testing by the US Congressional Commission on EMP showed that most vehicles are either fine or relatively easily repaired in an EMP event, so vehicle shielding is most likely unnecessary – unless these weapons exist.
The second is the effect of E3 on the power grid. Utilities have never been tested against a large scale EMP event – the most recent solar flare that caused major damage was in 1989 in Canada. A perfectly timed solar flare has the capability to fry the power grid – perhaps permanently. A full EMP, not just a solar flare, would have an unknown effect because utilities have never been tested to our knowledge on a full system level, only piece by piece. Utilities themselves acknowledge that cooling systems and fans are relatively easy to affect. Normally, that is not a problem, but if the cooling system for a nuclear power plant was disrupted, it could be catastrophic.
There are almost 200 commercial nuclear reactors in the US. One EMP could cause almost 200 simultaneous nuclear meltdowns if cooling [for the plants and their co-located spent fuel storage ponds] goes offline. At a minimum, the entire Northern Hemisphere would be uninhabitable. This would be an almost extinction-level event and it is a real threat. Even a solar flare could potentially cause damage if this is not taken seriously.
– Joel Ho, Founder, MobileSec Solutions LLC