was: HEU: portable Ge-Detectors are state of the art!

[Franz Schönhofer <franz.schoenhofer@chello.at>]

RADSAFErs,



I am a little surprised about this discussion: Portable Ge-Detectors are

standard and state of the art! I have bought my first portable

Ge-Detector about 20 years ago (before the Chernobyl accident) for our

task to be able to perform in-situ-measurements in the case of a local

accident or of a wide-spread contamination. In routine work it was used

in the laboratory to measure samples like aerosols, surface water,

precipitation etc. It was cooled by liquid nitrogen and we tested it for

the first time unvoluntarily in the very harsh conditions (rain pouring

down the whole day) of a granitic area. We did not only have all the

lines from the actinides in granite, but also could clearly distinguish

the Cs-137 lines from the fallout of the fifties and early sixties. Be

sure that the peaks were as sharp and clear as for any other stationary

detector - why should they degrade???



The same equipment was used after the Chernobyl accident to measure

Cs-137 in situ and to measure the contamination of cattle and sheep in

vivo. It was even used in tests in a helicopter - the problem of

microphony has been solved since then. 



The in-situ measurements at the Mururoa Atoll during the sampling and

measurement campaign of the International Atomic Energy Agency were

performed again with a portable HPGe-detector in connection with a

lap-top computer. Power supply was commercially available battery-packs

as I used them for my private video-camera, but we switched soon to a

portable electricity generator. 



In our task at Mururoa we used liquid nitrogen cooling, simply because

the instruments available had it and it was available on Mururoa. 



Instruments using electrically cooled detectors are to my knowledge

widely spread in automatic emergency warning systems like the German

one. 



All mentioned systems were of either Canberra or Ortec origin. None of

them had a mickey-mouse sign on them - I did not know that Walt Disney

produced Ge-Detectors?



Best regards,



Franz



Franz Schoenhofer

PhD, MR iR

Habicherg. 31/7

A-1160 Vienna

AUSTRIA

phone -43-0699-1168-1319





> -----Ursprüngliche Nachricht-----

> Von: owner-radsafe@list.vanderbilt.edu [mailto:owner-

> radsafe@list.vanderbilt.edu] Im Auftrag von Dimiter Popoff

> Gesendet: Montag, 31. Jänner 2005 15:47

> An: radsafe@list.vanderbilt.edu

> Betreff: Re: Detection of HEU, etc

> 

> 

>  I have not examined the details of their portable cooling system,

> so I don't know how much of the resolution they have managed to

preserve.

> 

>  As for fully-featured MCA and identification software on a portable

> system, they all are bound to be either mickey-mouse class and

portable

> or need an additional PC - all with one exception.

> 

> 

> Dimiter

> 

> 

> 

> ------------------------------------------------------

> Dimiter Popoff               Transgalactic Instruments

> 

> http://www.tgi-sci.com

> ------------------------------------------------------

> 

> 







************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/