Re: xenon behavior

[BYRPV@ccmail.ceco.com]

     Ed,
     
     This is a message from the Beating a Dead Horse to Death Dept...  
     
     Pure Xe-133 occupies only one cubic millimeter per Curie of activity 
     (sorry about the English units)  The Xe-133 used in the studies will 
     therefor take on the properties of whatever it is mixed with.  I am 
     not familiar with the carrier gasses used for Xe-133, but if they are 
     well mixed with air upon introduction to the room, the gasses will not 
     settle out.  As Dale Boyce pointed out, settling is a bulk effect.  To 
     help visualize this effect, imagine releasing a glob of corn syrup 
     into a glass of water.  As long as it stays together, it will sink and 
     stay sunk for a long time.  However, once you stir it into the water, 
     it will never come back out of solution on its own.
     
     Paul Vitalis
     byrpv@ceco.com
     
     Any opinions are my own, blah, blah, blah...


______________________________ Reply Separator _________________________________
Subject: xenon behavior
Author:  radsafe@romulus.ehs.uiuc.edu at INTERNET
Date:    11/2/95 5:26 PM


I have a question regarding the behaviour of xenon gas in a room, 
specifically Xe-133, which is used for lung ventilation studies in nuclear 
medicine.  Some people claim that it "sinks" in a room so that the xenon 
concentration is higher toward the floor; other people say that it remains 
at approximately a uniform concentration throughout the room.  This is an 
issue regarding the placement of exhaust ducts in a room.  Does anyone 
know whether the xenon concentration is markedly higher toward the floor? 
I will be grateful for any help with this issue.
Ed Leidholdt
US Department of Veterans Affairs
San Francisco
Leidholdt.Edwin@FORUM.VA.GOV
415-744-6243