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Focusing x-rays
-------- Original Message --------
From: jim bell <[email protected]>
Apparently from: [email protected]
To: Juan <[email protected]>, "[email protected]" <[email protected]>
Subject: Re: How much/what hardware does the rowhammer DRAM bug affects?
Date: Fri, 18 Sep 2015 21:30:32 +0000 (UTC)
> >Within the last couple of months, I think somebody was arrested for planning some sort of "X-ray death ray". http://nypost.com/2015/08/18/kkk-member-built-death-ray-machine-to-kill-muslims-and-obama-prosecutors-say/ But only a dweeb doesn't know that X-rays cannot be focussed. (With one very obscure exception not applicable here. Find it and get an "attaboy!". )
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> Its called Grazing Incidence
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> https://en.wikipedia.org/wiki/X-ray_optics
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> >Microwaves, OTOH, can be focussed rather easily. The frequency is 2.45 Ghz, at about 1 Kilowatt. (wavelength about 12 centimeters.) I'd have to consult a Radio Amateur's handbook, but a modern dish (intended or Directv or Dish network) could probably get 15-20 db of gain, compared with isotropic. An old-style 8-foot dish probably would do 30 db gain. That would be 100 kilowatts ERP.
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> >Such an unshielded (open) device would probably impair WiFi at 2.5 Ghz severely, if you're close to it, say a few hundred feet away. Fortunately, I think microwave ovens have better than 60 db of shielding. A few 10s of feet, away, hardware damage might occur if that full 1 kw were allowed to leak out.
> Jim Bell
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