Natural Science Forum / Physics / Particle Physics / May 2005

Hello,

While looking at a patent recently, I came across the following simple
expression for the range (R) of an energetic electron in the atmosphere
(at sea level pressure):

R = 543*E - 106

Where R is in centimeters and E is in Mev. The patent refers to this
formula as "Feather's rule", and stipulates that it's valid for 2.5 Mev
< E < 20 Mev.

I'm wondering, has anyone else heard of this expression? Is it fairly
accurate?

Regards,
Joe