[ RadSafe ] Can tritium produce bremsstrahlung?

Wed Feb 22 13:08:56 CST 2006

Stephane et al

You are describing external Bremsstrahlung which depends on the electron
penetrating the surrounding material which is "very variable" and the
photons originate in the material.

The photons in internal Bremsstrahlung originate in the nucleus and are
emitted instead of the beta particle (approximately 1/137 for every
election).

John

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl]On
Behalf Of Jean-Francois, Stephane
Sent: February 22, 2006 7:34 AM
To: 'Alan Watts'; Jean-Francois, Stephane; stiegli1 at msu.edu
Cc: radsafe at radlab.nl
Subject: RE : RE : [ RadSafe ] Can tritium produce bremsstrahlung?

As I mentionned off-line to one RADSAFER, I don't question the fact that
something can be measured. After all,  X-ray generation from Bremstrahlung
is a NATURAL phenomenon happening with protons and electrons. So If you have
protons, if you have electrons, if the electrons have speed (energy) and
they are likely to go near protons, well yes, you will produce X-rays. The
only question is how good of a reading can you make ?  20 Ci is close to
1000 billion  desintegrations per second.(740 billion if my SI units serve
me right...). With that many electrons, I can't imagine that NO X-rays will
be produced...And good for you,  NaI is a good tool to find a few X-rays, at
least way better then GM for low energy X-rays...

Now, since we are in this discussion, let me through another "brick" in the
pond (sorry I don't know if this expression exists in English):  How many of
us are telling in our Rad Safety training NEVER to use LEAD when you shield
from P-32 or high energy beta sources ? Now, how many of us are serious and
scared about this ? I am not. (as in "Not impressed" by the X-rays and dose
contribution from X-rays resulting from P-32 and lead...)

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 : Alan Watts [mailto:wattsa at ohio.edu]
Envoyé : Wednesday, February 22, 2006 10:19 AM
À : Jean-Francois, Stephane; 'JGinniver at aol.com'; stiegli1 at msu.edu
Cc : radsafe at radlab.nl
Objet : 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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