[ RadSafe ] New U detector

Tue Aug 19 11:20:12 CDT 2008

Reserve me a seat on the skeptic side of the aisle.  I see several
non-trivial problems with what is described:

1)  No detector can detect radiation that doesn't hit the probe.  When
you have a weak, shielded source and a small probe that is being moved
fast to survey a lot of containers, geometry is not on your side.

2)  If you are looking for the gammas from uranium, there is a lot of
noise in that part of the spectrum (from what I recall).  Reliably
picking out the photons you are interested in and ignoring the rest
could be hard.

3)  I am far from convinced that uranium is where such screening should
focus.  Uranium is a very bad choice for RDD material, and I am far from
convinced that there are any terrorist organizations that have secretly
set up facilities that enrich U-235 to weapons grade.  I think it would
be more profitable devising a system that would look for plutonium, but
that is probably even harder to find than uranium.

This sound more like a product in search of a market (or, failing that,
a government contract) than a real problem looking for a solution. 

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Peter Bossew
Sent: Tuesday, August 19, 2008 5:36 AM
To: 'radsafelist'
Subject: [ RadSafe ] New U detector 

Does anybody know technical details of this machine ?
Experiences ? Opinions ?

thanks,
Peter

-------------

> New detector can sniff out even low levels of gamma radiation
>
> By ANI on Tuesday, August 19, 2008
> Filed Under: Health News
>
> London, August 19 (ANI): Scientists from the Lawrence Livermore 
> National Laboratory in California have produced a new detector 
> sensitive even to low levels of gamma radiation.
>
> US shipping ports receive about 6 million cargo containers each year.
> Officials would like to be able to check each one for smuggled nuclear

> material, but today's detectors cannot process such numbers in a 
> reasonable time.
>
> These devices typically require an officer to search inside each
container.
>
> The gamma rays produced by radioactive materials can pass through 
> containers relatively easily, but uranium produces only small amounts 
> of such radiation.
>
> Now, according to a report in New Scientist, Joseph Farmer and 
> colleagues at the Lawrence Livermore National Laboratory in California

> have produced a new detector sensitive even to low levels of gamma
radiation.
>
> Their device is set to speed up screening times.
>
> It doesn't directly detect gamma rays themselves, but instead looks 
> for the hydrogen peroxide generated when the rays interact with water.
>
> The detector consists of an "electronic nose" chip coated with a thin 
> layer of water that is condensed onto its surface. When gamma rays 
> strike water molecules in that layer, the nose chip detects any
hydrogen peroxide formed.
>
> According to the inventors, as well as being more sensitive, their 
> design can pick up a wider range of gamma ray energies than 
> conventional detectors. (ANI)
>   

-- 

-----------------------------------------------------
Peter Bossew 

European Commission (EC)
Joint Research Centre (JRC)
Institute for Environment and Sustainability (IES) 

TP 441, Via Fermi 1
21020 Ispra (VA)
ITALY 

Tel. +39 0332 78 9109
Fax. +39 0332 78 5466
Email: peter.bossew at jrc.it 

http://rem.jrc.ec.europa.eu/

"The views expressed are purely those of the writer and may not in any
circumstances be regarded as stating an official position of the
European Commission."

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