According to Kodak airplane travel destroys your digital camera

Started Jul 2, 2011 | Discussions thread
theswede
theswede Veteran Member • Posts: 4,009
Re: In perspective ...

Ed Herdman wrote:

Eh, I mentioned alpha particles mainly in that I was looking for a connection after it was mentioned earlier (indirectly - the Wikipedia link to Single Event Upset).

I figured that. Just wanted to make sure no-one walked away from reading believing alpha particles are a threat to cameras somehow.

I believe you are mistaken about EMP not being caused by gamma rays - a US document illustrates it happening precisely that way:

Yes, as I read back I see I overstated; EMP is created by electrons receiving massive amounts of energy from the nuclear explosion, and the vehicle for this is gamma rays. However, the amount of gamma radiation to create a dangerous EMP wave is enough to pretty much melt an airplane, so I think there'd be other issues if this was the mechanism in question.

On the other hand, I think that - at least for currently known designs - you must be right that the major damage is done directly only by the electromagnetic pulse, and not directly by the gamma rays (only directly, with the pulse again the cause).

EMP is pretty much the same problem as static electricity. A strong pulse of high voltage current induced in the circuit fries the delicate transistors in silicon chips. It's not in the least subtle, and the effects mentioned in the video carry no resemblance at all to EMP damage.

One thing that I noticed was that there is the apparently misleading differences between not just energies but also between the units involved. Talking about Sieverts or Gray may have to do when trying to compare energies but those are generally biologically-centric measurements. And, as mentioned earlier, some of the literature plainly states that more energy is not necessarily equivalent to more damage in all situations.

The energy has to get absorbed to cause damage. This is why alpha particles are so much more damaging than gamma rays; they will get completely absorbed by whatever they strike due to their huge size. Gamma rays will for the most part pass straight through everything, including humans and camera sensors.

So the question becomes: Do gamma rays cause single event upsets? Even if they do, are they strong enough to cause actual damage?

Not directly, nor by causing alpha particle excitation (overgeneralized, but for the purpose of this discussion and the amount of gamma radiation present in airplanes correct) but they can by causing neutron particle excitation.

However, if this happens at airplane altitudes to a large enough degree to cause damage to sensors, it also happens at ground level at a large enough degree to cause damage to sensors. The difference in gamma radiation levels is not that large. And since there are no massive losses of sensor functionality at ground level, this mechanism can not be what the video talked about.

Your corrections are very welcome!

As are yours. To discuss this in a meaningful way a lot of simplifications are needed, and it's tricky to be on the correct level.

Jesper

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