EMP Electromagnetic Pulse: Circuit Effect
There are two types of EMP bombs, nuclear and non-nuclear.
The nuclear explosion generates ‘ionizing radiation’. Ionizing radiation is radiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from the orbit of an atom. It is the instantaneous explosive pulse of these spinning dislodged electrons which creates the Electromagnetic energy that causes the damage from the EMP effect.
The result is a a huge electrical current that is generated in an extremely short pulse of time. This huge current will pulse through a coil, which in turn creates a massive pulse of Electromagnetic energy that causes the EMP damage.
EMP Circuit Effect
The pulse of Electromagnetic energy (regardless of what produced it) induces currents in circuits (just think of circuits as anything with ‘electronics’ inside). Depending on the amount of Electromagnetic radiation, the current that is induced in these circuits can be huge or small. If the current is large enough, it will burn out a circuit due to internal resistive heating.
Circuits are everywhere, and they are in most every ‘thing’ that we use today. Anything that has a connected loop of wire is a circuit (including the power grid power lines and grid transformers).
EMP does not affect living organisms because we (and other living organisms) are not conductive in a way that will cause damage… we do not have a connected loop of wire in us. However if a person depends on a circuit to live (pace-maker, life support) then that would obviously be a bad thing.
It is important to remember that a circuit can be protected by building a Faraday cage around it. A Faraday cage is a conductive casing that prevents the Electromagnetic radiation from reaching the circuit. This type of protection is likely nullified if there is anything connecting the inside of the cage to the outside of the cage (power cords, circuit touching cage, etc.).
An electromagnetic pulse (EMP), in effect, destroys the junctions of the transistors in electronic circuits. It is a high voltage, high frequency, high energy pulse. It has little or no effect on living tissue, due to its extremely short duration. Having said that, it WILL have a potentially terrible effect on humans and human civilization due to the dependencies that most of us have on electronic infrastructure to keep us fed and alive.
There has apparently been considerable and renewed interest in EMP Weapons today by many nations. Unfortunately, indirect consequences of using such weapons will be just as, or more devastating than other weapons of mass destruction given the reliance that developed nations have on electronic infrastructure.
It amazes me how many people out there don’t have a clue that 1 Nuclear weapon exploded 300 miles above the US would take America back to the stone age.
Everyone needs to read the book “One second After” by William R. Fortschen.
I agree. The book should be a ‘must read’ for all preppers.
One Second After
Without a doubt, one of my favorite books of any genre.
Mine as well. Along with the Patriots, survivors series By James Wesley Rawles. Very realistic presentation of the potentials.
I believe that an EMP of great severity and/or quantity will be the Nuclear Zombie Apocalypse.
No Stone Age.
And that there will be many seconds after, – as the Earth Dwellers slowly die of radiation poisoning. The Ground Dwellers may surviive longer, (Morlocks, just kidding,)… Forever under ground?
Most of us here know the half(long) lives of Nuclear Isotopes right?
I know of the book you speak of, and I have read every review and write up about it, and believe it to be well written and informative.
knowing the story line, and that, not being my genre per se, and the fact that I am not a ‘real’ Prepper in the truest sense of the word – I will probably not read it.
On a lighter note, I have a three day weekend so I can work my second job round the ‘homestead’ here.
We are having an incredibly mild Fall.
I need to do some re-potting!
@Anonymous, the fact that you’re using the word “homestead” implies a bit of prepper in you… ;)
Decades back the US’s Star Wars program was developing proton beam weapons. The source of power was based on basic power generation by passing a magnetic field through a conductor to create a huge pulse of instantaneous energy. The magnetic wave of energy came from a high explosive blast (magnetic wave) within a steel ball (the conductor) and being directed through advanced, high tech gear producing a proton beam of energy. Only problem, it’s only good for 1 shot as it self destructs while firing. One can only imagine where advancements in technology have lead this type of weaponry idea today. My guess is something exists to replicate an EMP via, not air-born Carrington effect type disruption, but a ground pulse weapon used to cause reverse current flow through electronics from the grounded side, much like a solar flare induces. Nothing to launch, nothing to shoot down. Just a ground level, localized back flow of power as large or small as wished. This is where the true vulnerability lies as all electrical components are grounded with little to no regard for protecting themselves from current back flow. Tesla used to make the ground around his lab light up with electricity. That would have taken out ANY modern day electrical equipment, electronic or otherwise.
Do you think that electronics placed in garbage bags and then placed in a 55 gallon steel drum would work? Or would they need to be in boxes and then in the drum. I buy 55 gallon drums from our local bakery factory (little Debbie) for $10 every chance I get (they go fast). I have thought about loading up a drum with some solar lights, a solar charger, inverter and a small TV with DVD player. Smiles ;o)
@Christine, don’t forget to keep the lid on the cans ;)
There is debate regarding the requirement for the electronic devices (inside the can) being insulated from the metal of the inside of the garbage can (Faraday cage). My own personal opinion is that the EMP pulse will not penetrate the surface molecular layers of the metal as it travels around the surface of the cage… meaning the inside molecular layer does not become charged (zapped).
Having said that, why not be safe and isolate the devices that you wish to protect anyway? Its easy enough to do… cardboard, etc.
Is there any validity in wrapping items you want to protect (e.g laptop, iPad) in tin foil? Theoretically, it should protect them, but would it be enough? Anyone? If not, what do you suggest?
Yes, but in this case I believe that you should first wrap the product in a non-conductive bag and then wrap it in aluminum foil. You could then wrap it again in a non-conductive bag and then wrap it yet again with aluminum foil (double wrapped) for more assurance of protection. For something as important as a laptop, I would use extra precaution.
Do you think that this simple technique would work for vehicle electronic components – wrapped in situ maybe? Could you EMP proof your car by adapting this technique?
Or would the common earth of the block/chassis/bodywork render it ineffective?
Fortunately I have an old mechanically injected Diesel truck, but obviously this still leaves the alternator regulator etc.
I believe the answer is this… If you want to be sure of a running vehicle, go out and purchase an older one without electronics. Most 1970’s vintage and earlier will suffice. I’m sure you can get them pretty cheap these days ;) May require a little work to get them running well enough, being 35+ years old (I can still remember my 1970 Dodge Challenger back in the day… what fun). A perfect choice would be an old pickup truck.
I bought a 1969 Ford truck for just that reason. I was lucky enough to find one in perfect running order and looking decent also for a very fair price ($3,000). I love my truck!!! My husbands jeep has a get home bag in it in case of EMP as it will die!!! My get home insurance in my truck is a full tank of gas! Also another good deal I know in our state an antique tag is $7 and you never have to renew it!!! Saves money that way also!!!!
Nice… and it was only $3K. Who says you have to go out and buy ‘new’ when you can get a working vehicle for a fraction of the cost… and one that will actually work after an EMP (which would then be worth far more than any new car ;) )
That was my plan… I checked the distributer first thing just to make sure it had not been converted. Points and condensor!!! Carb up top and a new one at that!!! Yup bought it on the spot, paid cash and didn’t try to argue the asking price… I got it off a craigslist listing… Good paint job, good tires, Nice interior, dash with no cracks, spray in bed liner and runs like a trooper…, The only thing that should die because of an EMP is the stereo! So it pays to shop around!!
Sounds like a great bargain to me, Christine.
I don’t know what state you are – the $7 antique tag for life is a bargain too!
A vehicle like this would be like gold after an EMP.
I wonder in a situation like this if the authorities would try and cease the vehicle.
If people see you driving too – they may want it as well.
With a 0.50 Cal on it – you should have no problems!
Thats really cool.
Most vehicles since 1980 have some type of computer, even those with a carburetor.
So if an EMP happens the computers, electronics and stereos will get fried like scrambled eggs and those vehicles will not run.
Unless you have your vehicle in an EMP protected building at the time the EMP happens, which will be a matter of luck.
A lot of people today – their world is “the matrix” – android phones, the internet, texting, facebook – so if an EMP happens – it will be back to “the stone age” of technology – just to phrase it.
With your ’69 Ford Truck Christine you are prepared! – Well Done!
Prepared at least till the gas runs dry….. At least I will get home!
That reminds me to mix the “heet” with the gas in the shed.
Actually, a properly deployed High Altitude EMP cannot be protected inside a metal garbage can, nor a microwave oven (which by design is a type of Faraday Cage). Wrapping aluminun foil around an item or with carboard or both or double both put inside a box with copper screen duct-tape inside a metal trash can or any other such idea WILL NOT protect any electronic device inside.
The amount of shielding to protect electronic devices from the E1 & E2 components of a HEMP need to be in the neighborhood of 130db to 140db of sheilding… a metal trash can may give you 20db – meaning – don’t waste your time. The type of metal and thickness can be mathmatically calculated but for most metals you are looking at somewhere around 1/2 inch + thickness. Also, the shape is important – it must not have sharp edges – it needs to be rounded… the opening needs to have a “tongue in groove” type opening that can be ratched down with force to create a secure metal-to-metal contact that will not allow seepage of the dreaded E1/E2 pulse.
Most theories floating around the internet are just plain wrong and have no vetted science behind them.
I recently attended a self reliance expo in NC and there were some “EMP” bags for sale… they were a mylar type zip lock… Upon close inspection they were “electro-STATIC” protection devices not elector MAGNETIC protection… one bag would give you about 18db of protection… and if you put a ‘bag in a bag’ the extra protection only increased by about 3db… so to get to 120+ db protection you’d have dozens of bags inside of bags… impractical and costly…
My friend, “The Engineer” and I started a podcast about NBC’s new show “Revolution” which by all appearances (at least the trailers) looked like an EMP event… We thought we would use the show to educate people about the real threat and real protections folks could do in the event of an EMP. We also talk about the real world threats that could take out our entire grid. There is an artical that shows how to do a simple test to determine if microwaves or garbage cans can be effective Faraday cages… you can conduct this same test…
[links removed due to Comments Policy]
@Jake, You bring up a good point regarding “properly deployed” (a key to your argument) and the inference of your geographical location with respect to the EMP itself (as well as the strength of the EMP), and the matter of decibels (another key). The topic and understanding of decibels is mostly not understood by people who have not been schooled in it.
The dB is one that I am very familiar with, due to my previous career. It is surely true that if your ‘garbage can’ makeshift Faraday Cage is located underneath the explosion, that it will probably do little to protect (assuming a sufficient strength of EMP). The further away you are, the more likely your ‘garbage can’ will be effective. I chose to keep this article simple, so as to encourage the likelihood of someone actually taking action.
It’s mostly common sense, the closer you are to the ‘explosion’, be it EMP or otherwise, the more protection you will need to go unscathed. For those interested, look up the inverse square law…
If you happen to have a chart or data that cross references EMP magnitude with distance and protective measures (metal type, thickness, etc.), I’d love to see it. Use the Contact-Us form at the top of the page and email it to me. Thanks…
By the way, regarding the microwave, the frequencies (plural) of an EMP (broadband) are such that the wavelengths are LONGER than that of the microwave itself. Meaning… you can’t get bigger rocks through a small sifter… meaning the grid on the front door will provide protection. Again though, the topic of ‘how much’ protection (dB) is quite another story. Is it enough? Well that depends…
Jake, what you wrote is really interesting.
I was wondering since you mention that a lot of information on the internet is not correct and about what you wrote – can you give good advice on a practical design that you could make a really good faraday cage for a higher db of 130 db/140 db from regular everyday items?
Good question. I will profess I am not an engineer… my Podcast co-host is an engineer and he did all the math – you know, the blackboard type formula-math that makes my head hurt. There is MIL STD 188 – 125 – google that…
Read “The Engineer’s” article on our podcast site here: [link removed: Comment Policy violation…] – he has links to MIL STD 188-125 which has the specs on how to sheild for EMP – keep in mind this is info on standards about 20 years ago and therefore The Engineer believes they are out of date as more powerful specifically designed-EMP nukes may cause these standards to be subpar…
From Wikipedia – there as many subparagraphs of MIL STD 188 – but 125A states “125A – High-Altitude Electromagnetic Pulse (HEMP) Protection For Ground-Based Facilities Performing Critical, Time-Urgent Missions”
[link removed: Comment Policy violation]
You will notice it drops off around 10 to the 9th unit – anything above that is not in jeopardy of EMP… this is where microwave ovens are… so the microwave oven itself is safe but the control panel of the oven is “Toast” – pun intended ;>)
Here is an interesting Powerpoint that sheds some light on EMP – go to our home page: [link removed: Comment Policy violation] I just posted to the blog with a link to a PDF report that has lots fo facts.
check out The Engineer’s test he ran using a radio and microwave oven to prove it does not function as a way to protect electronic gadgets: [link removed: Comment Policy violation]
So, to answer you question… I just spoke with The Engineer and he says if you read MIL STD 188-125 it will give “permeability” specs for the shielding standards. Then you would need to look up permeabiity charateristics of different metals. You should be able to find a chart (probably metalurgy website) to see what the perm. char of each metal will be… You will see that steel is very good for shielding but the drawback is very heavy… you may find that an alloy will be very light and thin for use but very very expensive… There are tradeoffs…
Also, these are the type of questions The Engineer would love to answer on our podcast… you can send technical questions about EMP to [link removed: Blatant repeated self-promotion Comment Policy violation… one more and this IP will be banned] and he will be happy to read your questions, comments, speculation, and even opposing opinions on the air and give you his take. He is writing an Ebook as we speak to go into great detail about what a HEMP/CME event is, the likely aftemath and how you can inexpensively prepare and protect your gear and even how to choose and fortify a vehicle for post-EMP use.
I have read the first draft and it is good and thorough…
Hope this helps, if not, let’s try again…
[from the Moderator: Please refrain from the obvious self promotion link injection. We’ve had to intervene before, so one more strike and unfortunately you’re out. Plus, if you are writing an Ebook, I would suggest using spell check]
If it is that simple to fling America into the dark, Why has it not been done already? there are MANY rogue nuclear nations that would love to incite this type of chaos in The U.S. along with Many “missing” Russian nuclear warheads after the collapse of the USSR that have ,no doubt, found there way to unsavory destinations. The capability for an entity to accomplish this task obviously exists so….What are they waiting for?? Opinions anyone…….
@spidermonkey, The reason is most likely something called “Mutually Assured Destruction” also known as MAD. Having said that, I do believe we are in an ever increasing danger of ‘rogue’. In addition, there is always the ‘natural’ danger of our Sun shooting off a major X-20+ flare.
@spidermonkey – I did say it was “simple” but I didn’t say it would be easy… getting any nuke warhead that would be big enough to render our entire grid useless would be a monumental task. Those same missing Russian nukes haven’t been used ANYwhere yet… Why not? Just because someone who shouldn’t has it does have it doesn’t mean they can or will use it.
However, the Terrorist element is the scariest angle. They do and would use it IF they could get them and could figure out how to mask their transport and defeat the intelligence network and could figure out how to launch them.
If you google “[name removed to avoid NSA sniffers]” magazine you would find references to an online magazine printed in English and was published in America (I think it is now defunct) I got the very first edition which had a full article about how an EMP weapon was the ULTIMATE dream by Jihadists… they talked about how IF they could get one they could kill the “Great Satan” with one blow. They were drooling over this opportunity. They only have to be right once… and we have been very diligent to prevent further terrorist attacks. It almost seems like a miracle that we haven’t been hit again. They are patient though… How long did the 9/11 terrorists train and plan etc before they pulled the trigger?
So, it is a “black swan” event but it still does not explain why our government wouldn’t spend $2 Billion to harden our grid, especially when they are printing money to the tune of $85 Billion PER MONTH with the last two QE Infinity initiatives by the Fed…
I don’t believe the MAD theory would apply in this situation and here’s why… Let’s take the example used of a missle fired from a shipping container onboard a non descript generic ship. Our grids go out. The American governments determination to “fully investigate and bring to justice those involved in this terrorist attack” would be rendered impossible due to lack of electrical power. The ability to investigate such an incident would be brought to a standstill. and the desire to eliminate ‘collateral damage or striking the wrong targets or entities would basically leave our country defenseless. So with no one to strike M.A.D. would not apply.
@spidermonkey, Yes, you made my point exactly regarding ‘rogue’. Agreed. That is what I was attempting to infer from my remark, “Having said that, I do believe we are in an ever increasing danger of ‘rogue’”.
If other than a rogue unknown, Mutually Assured Destruction would certainly be implemented post haste. Assuming the sitting president has the ba$$s.
Thanks for the great conversation and points of view.Intelligent conversation and debate is a wonderful thing. Stay safe and well.
I am enclosing my generator in a structure and want to line said structure with hardware cloth to form a Faraday cage. What size hardware cloth do you recommend?
The key to Faraday protection is to have the mesh size to be much smaller than the wavelength in question. An EMP pulse is fairly broadband. Having said that, for example, the frequency of a microwave oven is apparently 2.45 GHz (gigahertz) and has a wavelength of 4.82 inches. Since the holes of the screen mesh of a microwave oven are extremely small compared to the wavelength of the microwave itself, little radiation can leak out.
It has apparently been fairly widely accepted that a mesh size approximating that of a screen window size mesh, would be adequate.
It can be easier to understand EMP if you look at it as a kind of high-power electromagnetic transmission, like putting hundreds of thousands of joules in a radio transmitter all at once. Now, almost any circuit can act as an antenna to any electromagnetic signal, but most circuits aren’t well-suited to these electromagnetic signals. That means that most levels of transmission (like radio, wifi, or a nearby arc-welder) have an almost imperceptible effect on most circuits. If you multiply the power of that transmission by a million, you can get enough to damage the circuit.
The important thing is that calculating much damage is dealt to a specific device depends on the frequencies and magnitude of the blast, as well as shielding, characteristics of the device (like the length of wires), and sensitivity of the device to interference. An EMP that is excellent for taking out computer chips would not damage power lines as easily.
As noted above, EMP pulses, especially high-frequency ones, can penetrates even copper to certain depths (a college-style electromagnetic wave penetration problem), so shielding is more effective the thicker the shield.