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Re: microwave, RF heating

At 10:08 AM -0500 5/29/00, brian whatcott wrote:

Actually Jackson's graph (Fig 7.9 p291 op cit) shows a steeply climbing
absorption coefficient for seawater to 100 MHz - John assumes (not
unreasonably) that this continues through 840 MHz.

Given this assumption, seawater would absorb ten times more with distance
than fresh water giving an attenuation length of 1 cm for saline
vs 10 cm for fresh water at the cellular frequencies.


Even tho conductivity seems to be important, we mustn't neglect to
realize that it's a bit of a 'GoldyLocks and the Three Bears' thing.
If the conductivity is TOO high, we'll get the shielding/reflection
that has been referred to. Probably NOT significant for human brain
tissue, but PERHAPS pertinent to salt water in ovens.

If you line the _inside_ of the water container with Al foil, the
water won't heat much either.

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