[ RadSafe ] Can tritium produce bremsstrahlung?

Wed Feb 22 12:51:14 CST 2006

My take on this. Whether you can see the x-ray with a pancake GM tube 
depends on both the amount and the type of containment vessel its in. I 
don't think you would produce any measureable bremmstralung x-ray in air 
or water by H-3.

If the amount in question is less than 1 Ci, then it would be hard to 
distinguish from background with a standard pancake GM. Only a fraction 
of x-ray is produced near 18.6 KeV, and the efficiency for a GM using a 
pancake to detect less than 18 KeV continuous x-ray goes down fast.

On the other hand, if you're talking a Ci or more and its contained in a 
steel pressure tank (not smart), you will definitely see it with a 
pancake GM. A lot of x-ray is being produced, and that's why something 
other than steel is used.
-Russ

Alan Watts wrote:

> I was able to detect 0.15 - 0.2 mR/hr with a 1" NaI on a H-3 exit sign 
> with 20 Ci on 12/85.
>
> Alan
>
> Alan Watts
> RSO
> Ohio University
>
> --On Wednesday, February 22, 2006 7:40 AM -0500 "Jean-Francois, 
> Stephane" <stephane_jeanfrancois at merck.com> wrote:
>
>> Can you share the reputable sources that tells you that H-3 (in any
>> amount!) can be detected by a Beta pancake ? A Geiger counter (gas 
>> chamber
>> technology, this is what UI assume you are saying by "pancake") is very
>> bad for detecting X-rays, less then 1 % efficiency for pancakes if my
>> memory serves me well. So obviously "any amount of H-3" is a bit far
>> fetch for a pancake. I would not recommend AT ALL to use a pancake for
>> tritium, beta will not go through the window and Bremstrahlung will not
>> be detected. Is this a clear answer ?
>>
>> Let's but it this way: I have a large tritium lab (37 TBq...oups, 
>> 1000 Ci)
>> here and I would be VERY HAPPY if I would be able to control 
>> contamination
>> with a pancake.  Please check your sources for info.
>>
>> This is not a stupid question, hopefully MY ANSWER is not stupid 
>> either !
>>
>> Regards,
>>
>> Stéphane Jean-François, Eng., CHP
>> Manager, Environmental and Health Physics services
>> Merck Frosst Canada
>> 514-428-8695
>> 514-428-8670
>> stephane_jeanfrancois at merck.com
>> www.merckfrosst.com
>>
>>
>> -----Message d'origine-----
>> De : radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] De la
>> part de JGinniver at aol.com
>> Envoyé : Tuesday, February 21, 2006 5:35 PM
>> À : stiegli1 at msu.edu
>> Cc : radsafe at radlab.nl
>> Objet : Re: [ RadSafe ] Can tritium produce bremsstrahlung?
>>
>>
>>
>> In a message dated 21/02/2006 21:25:10 GMT Standard Time,
>> stiegli1 at msu.edu   writes:
>>
>> Could  someone please tell me if a beta pancake is able to detect 
>> tritium
>> in any  amounts?  I have heard from reputable sources that it can.
>> Obviously the beta is too weak to be detected so as I understand it, the
>> only way would be to detect the bremsstrahlung radiation.  Is tritium
>> energetic enough to produce bremsstrahlung?  Can anyone tell me how  
>> much
>> would be needed?  I apologize if this is a stupid question but  nobody
>> has totally answered the question to my  satisfaction.
>>
>>
>>
>> According to the Lawrence Livermore National Laboratory "Because this
>> attenuation and/or stopping process produces a bremsstrahlung radiation,
>> the
>>
>> detection of this tritium bremsstrahlung appears to be the most direct
>> and   advantageous way to monitor for STP [stable metal tritides] air
>> contamination.".
>> They have a short article on the development of a CAM for  the 
>> measurement
>> of
>> STPs at : _http://www.llnl.gov/es_and_h/hc_dept/spd/MetalTritides.html_
>> (http://www.llnl.gov/es_and_h/hc_dept/spd/MetalTritides.html)
>>
>> However it's not clear what measurement technology they are planing to
>> use   for the detector.  Most modern CAM use Passively Implanted Planar
>> Silicon  (PIPS) detectors.  I would have thought that if it was possible
>> to  use a pancake
>> geiger to measure tritium bremsstrahlung, then things like  the 'Flat
>> Ferret'
>> from Overhoff would not be in production.
>>
>> Regards,
>> Julian
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