[ RadSafe ] Can tritium produce bremsstrahlung?

Wed Feb 22 12:07:08 CST 2006

Careful about quoting dose rates using a NaI for low energy x-rays.  NaI over responds to low energy x-rays sometimes as high as 8x. 

Matt Williamson
Radiation Safety
willim01 at mskcc.org 
-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf Of Alan Watts
Sent: Wednesday, February 22, 2006 10:19 AM
To: Jean-Francois, Stephane; 'JGinniver at aol.com'; stiegli1 at msu.edu
Cc: radsafe at radlab.nl
Subject: Re: RE : [ RadSafe ] Can tritium produce bremsstrahlung?

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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