North Korea is EMP Capable

[G27]

He said the main precaution was to always have backup equipment powered off so they can haul out the backups and turn em on if an EMP takes out the powered-up equipment. Dunno about the accuracy of that report or whether it would be effective. Wonder if an EMP really would be less likely to fry a circuit which is powered off?

In theory it makes no difference, but if anyone has fairly extensive research on hardening electronics against EMPs, it would be the US and Russian militaries.

[Oh Shoot]

....

IOW, there's no going back to the 1800's from a few HEMPs. Could screw us up pretty good, yah, but Lights Out and One Second After are just interesting fiction...

If you're wrong, only the TGOers quite near you will have the chance to give you an Oh Yeah?

- OS

[mikegideon]

Well, they say that MOV's arent fast enough to catch the E1 pulse, which has a rise time in the nanoseconds, and a duration of about a microsecond. I think they're not considering the capacitance of an MOV though, which is probably significant enough to swallow the pulse without even firing the MOV. It's mentioned in the article that in some cases, the junction capacitance in a semiconductor can even significantly dampen the E1 pulse.

This is a little slice of battlefield electronics. Nothing special exept for Milspec components...

It lives inside some heavy EMI shielding to keep it from interfering with the radios. I got involved in the project when SOCOM started using it. It already had widespread deployment, but SOCOM is much sneakier than the average guys, and need quieter radios. Most of my involvement in military products had to do with making EMI spec. I'm not sure it qualifies me to comment on electromagnatic fields, but I'm doing it anyway :-)

It's a real complex subject. I can't comment on the government studies because I haven't read them. I just have a good feel for blown up electronics and high electromagnetic fields. One of these days, I'll read thru all the stuff. I may wait until North Korea REALLY has the capabilities before I do.

[mikegideon]

If you're wrong, only the TGOers quite near you will have the chance to give you an Oh Yeah?

- OS

But... he's not wrong.

[Guest Lester Weevils]

Well, they say that MOV's arent fast enough to catch the E1 pulse, which has a rise time in the nanoseconds, and a duration of about a microsecond. I think they're not considering the capacitance of an MOV though, which is probably significant enough to swallow the pulse without even firing the MOV. It's mentioned in the article that in some cases, the junction capacitance in a semiconductor can even significantly dampen the E1 pulse.

[snip]

It's a real complex subject. I can't comment on the government studies because I haven't read them. I just have a good feel for blown up electronics and high electromagnetic fields. One of these days, I'll read thru all the stuff. I may wait until North Korea REALLY has the capabilities before I do.

Thanks Mike

That wikipedia article seems pretty good.

Electromagnetic pulse - Wikipedia, the free encyclopedia

I'm not qualified to discuss but is interesting.

At 50,000 volts per meter, a 63 mil double sided circuit board "facing" the E1 pulse might see about 80 volts between the front side and back side stripes?

An 8 inch board edge-on to the pulse might see 10,000 volts between the near and far ends? But if the power supply traces are evenly distributed, the power supply and ground might have about the same common mode voltage "riding the spike", so the main risk might be to device inputs and outputs?

As you said, low impedance circuitry might fare better unless there is a lot of push behind the pulse.

A pulse so short reminds of a dirac delta function. Wonder if the E1 is more a noisy spike or a spike of noise?

Given that IEC duration of 1 us then the lowest harmonic of interest may be in the ballpark of 1 MHz?

If it is a noisy spike with a rise time of 5 ns, then the higher harmonics may fall off above about 200 Mhz?

On the other hand if it is a spike of noise, then the higher harmonics could keep on going on up there?

A 1 us pulse, the E1 envelope ought to have a front-to-back length of about 300 meters moving down into the atmosphere at the speed of light?

It says "These 2 MEV gamma rays will normally produce an E1 pulse near ground level at moderately high latitudes that peaks at about 50,000 volts per metre. This is a peak power density of 6.6 megawatts per square metre."

Does that imply that a 1 meter area antenna would dissipate 1 microsec of 6.6 megawatts, or in other words 6.6 watts integrated over 1 second?

Maybe bare chips embedded in conductive foam in their storage containers ought to survive OK?

Component level repair has become rare, supplanted by unit or subassembly replacement. Maybe an EMP would make component level repair more practical and essential? There would be so many fried devices that we would probably be forced to replace components rather than entire subassemblies?

[mikegideon]

A LOT of chips in circuit will survive. I did read the Wiki article a few days ago.

[Guest Lester Weevils]

A LOT of chips in circuit will survive. I did read the Wiki article a few days ago.

Yes, your reference to the article made me read the wiki after your earlier comments. Thanks for the good reference.

Edited March 22, 2011 by Lester Weevils

[Spook]

A LOT of chips in circuit will survive. I did read the Wiki article a few days ago.

Then it must be true!

[mikegideon]

Then it must be true!

You been skimming this thread? I didn't make that statement because of the wiki article.

[Spook]

You been skimming this thread? I didn't make that statement because of the wiki article.

Sorry, no offense intended... My comment was meant to be a reflection on Wiki (which is quoted as gospel far too often, imo), not on your statement. (Been traveling or would have responded sooner.)

Cheers...

[Guest Lester Weevils]

Yah, wakky pedia is hit and miss.

They seem to be the least controversial on science/math topics (except possibly political-entwined science topics such as anthropogenic global warming).

[mikegideon]

Sorry, no offense intended... My comment was meant to be a reflection on Wiki (which is quoted as gospel far too often, imo), not on your statement. (Been traveling or would have responded sooner.)

Cheers...

None taken. There's a lot of good info on there. You just can't trust ANY single source these days. Technical stuff tends to be better than other things on there