Re: About Alpha radiation...

["Jean-Francois Avon" <jf_avon@citenet.net>]

On Thu, 25 Mar 1999 09:55:03 +0200, Tim Griffiths wrote:

>Alpha's from radiative decay, yes. Alpha's from space can have energies
>at least two orders of magnitude higher. Don't forget as well that an
>Alpha doesn't need to penetrate to the conducting layer (2DEG) in a
>FET transistor to cause damage - charging effect by the secondary
>electrons are enough to stop it working.
>On the other hand, I agree with you that for a chip in a case, in a box,
>under a desk, in a room then it should be safe. 

Well.  I assume here that you mean "sea level alpha from space".  Since, AFA my 
books are stating, the typical free mean travel is in the order of 4 cm, two 
order of magnitude would give 4 meters.  Pit that against several kilometres of 
nominal density 1 air and the alpha count would be pretty low... thus I conclude 
that the two orders of magnitude energized alpha are observed at sea level.  
Isn't it?

I have a table, which I will digitize, OCR and post.  It is from Rasetti.  Or 
maybe I could look in my old CRC handbook...  Will check it out.

>Tim May wrote:

So, Tim did not killfile me after all!  :-)

Ciao CPunks!

jfa