Re[2]: Cloud Chamber

["Potter, Charles" <CAPOTTE@saix367.sandia.gov>]

     Am-241 is a good alpha source, however, it does emit two different 
     energy alpha particles.  There are two excellent sources of alphas.  
     One is Gd-142, which is difficult to obtain because, I understand, 
     plating of Gd is difficult.  The second is Po-210 which can be very 
     easily made in a laboratory.  This is done by diluting Pb-210 solution 
     with dilute HCL, pouring it into a vessel with a copper disc (masked, 
     except for the desired source area) and agitating for a few hours.  I 
     used this type of source in my Ph.D. research with very good results.
     
     Gus Potter
     Sandia National Laboratories
     PO Box 5800, MS1095
     Albuquerque, NM 87185
     (505) 844-2750
     CAPOTTE@sandia.gov
     
     
______________________________ Reply Separator _________________________________
Subject: Re: Cloud Chamber
Author:  radsafe@romulus.ehs.uiuc.edu at ccsmtp 
Date:    1/10/95 6:39 AM
     
     
                      RE>>Cloud Chamber                            1/10/95
The kit sounds great but it sounds like the only thing you really need from 
them is the source.  If you want the source to be more familiar, you could 
always take an air sample in the basement of your building before class.  I 
would imagine you could get sufficient radon progeny to conduct your 
experiment.
     
Rob Forrest 
     
-------------------------------------- 
Date: 1/10/95 7:11 AM
To: ROB FORREST
From: radsafe@romulus.ehs.uiuc.edu
Received: by rsomacserver.rso.upenn.edu with SMTP;10 Jan 1995 07:09:45 +1000 
Received: from romulus.ehs.uiuc.edu (romulus.ehs.uiuc.edu [128.174.74.24]) by 
vixen.cso.uiuc.edu (8.6.9/8.6.9) with SMTP id GAA12080; Tue, 10 Jan 1995 
06:09:51 -0600
Received: by romulus.ehs.uiuc.edu (NX5.67d/NeXT-2.0)
 id AA05753; Tue, 10 Jan 95 06:05:54 -0600
Date: Tue, 10 Jan 95 06:05:54 -0600
Message-Id: <9500107897.AA789750504@ccmail.arinc.com> 
Errors-To: mandel@romulus.ehs.uiuc.edu
Reply-To: radsafe@romulus.ehs.uiuc.edu 
Originator: radsafe@romulus.ehs.uiuc.edu 
Sender: radsafe@romulus.ehs.uiuc.edu 
Precedence: bulk
From: bkolb@arinc.com
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu> 
Subject: Re: Cloud Chamber
X-Listserver-Version: 6.0 -- UNIX ListServer by Anastasios Kotsikonas 
X-Comment:  Radiation Safety Distribution List 
     
David Bromwich writes:
>I saw something in a physics journal 10 (or was it 20 ) years ago 
>describing a simple cloud chamber for demonstrating the range of 
>alpha particles in air.  I think it used methanol and dry ice,    
>producing a supersaturated methanol atmosphere.  I intend to use the 
>amerecium source from a smoke detector, to make the source feel 
>familiar to my students.
     
There is an inexpensive kit (under $30US) made by The Science
Source in New England and available from the Fisher Scientific Educational 
catalog.  It consists of a flat plastic jar, a styrofoam block, a 0.1 uCi 
Pb-210 source and instructions (total value other than the source is less 
than a dollar).  You supply the dry-ice and alcohol.  You place a piece of 
blotting paper in the plastic jar (actually a plastic cylinder about 5cm 
tall), soak it with alcohol, and put the lid on.  Place the jar on dry-ice, 
which in turn, is resting on the styrofoam block.  Just at the moment when 
a mist start to form in the jar, remove it from the dry-ice -- otherwise 
you get freezing and have to start over with fresh alcohol.  This takes a 
little practice.  It's at that point you will be able to get alpha and beta 
tracks in the mist.  Put the jar back on the dry-ice and repeat.  I don't 
think you will have good luck with an Americium source due to the high 
emission rate and the inability to deionize this type of chamber quickly. 
You are better off with a very weak source.
     
Good luck.
     
bill
bkolb@arinc.com