[ RadSafe ] Ra-226 Static Eliminator Bar

Tue Apr 12 09:28:53 CDT 2011

I have seen similar bars, they are radium metal compression welded to a 
thin  gold foil (visible under the mesh grid on the bar's front).
The weldment is then inserted in a metal housing and fitted with a screen 
mesh - assuming to protect the bar foil from abrasion & contact.

They are used for static charge elimination  - alpha particles can pass 
through the foil eliminating. static - . The alpha radiation creates a 
cloud of ionized air - through this ionized air gives up its accumulated 
excess electrical energy (static), thereby reducing or eliminating the 
detrimental static.  These were in use by Kodak (or was when I was last 
there in 2007) to remove static electricity in film in manufacturing - 
although they generally have switched to similar bars containing 
Americium-241 and or Polonium-210.  Variations are still made by NRD in 
Grand Island, NY (USA). 
http://www.nrdstaticcontrol.com/LinearIonizers.html

They were and are also common to use for static elimination in other 
scientific applications like precision balance / mass measurements to 
remove static electricity - they usually have a screw on the bottom to 
affix a metal ground strap of some sort.

In my experience with these is that you can expect the foil itself to be 
surface contaminated with radium from alpha recoil creep so avoid touching 
the foil - the mesh should do this.  It would be prudent to wipe test the 
mesh and entire item for contamination in my opinion.

-Ken

Kenneth Marshall, RRPT
Radiation & Laser Safety Officer
Caresream Health
Rochester, NY 14615

From:   "BRISSON Nicolas" <nicolas.brisson at irsn.fr>
To:     "The International Radiation Protection \(Health Physics\) 
MailingList" <radsafe at health.phys.iit.edu>
Date:   04/12/2011 10:06 AM
Subject:        [ RadSafe ]  Ra-226 Static Eliminator Bar
Sent by:        radsafe-bounces at health.phys.iit.edu

Hi all,

2 years ago we had a short discussion about radium-226 static eliminator 
bar (excerpt below).
At that time I could only find the article mentioned below.

Last week I found a static eliminator bar from US Radium Corp. 

As the dose rate ranged from 1 mSv/h to 1,6 mSv/h between 5 and 0 cm from 
the bar, we didn’t spend too much time studying it at close range. So I 
would be interested in layouts or any information available about these 
bars

Thanks,

Nicolas Brisson
IRSN/DEI/SIAR
route du Panorama
92262 FONTENAY AUX ROSES
tel : +33 1-58-35-87-24
por :  +33 6-08-76-55-32

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

From: BRISSON Nicolas <nicolas.brisson at irsn.fr>
To: radsafe at radlab.nl
Sent: Wed, 28 October, 2009 20:58:57
Subject: TR: [ RadSafe ] Ra-226 Static eliminator bar

Hello all,

I don't have much information on this topic but you can find an article at 
the web address below.
American Journal of Public Health (August 1950) :

            http://www.ajph.org/cgi/reprint/40/8/943.pdf 

In this article you can read that these static eliminator bars contained 
25 or 50 µg of radium 226 per linear inch.
Some Ionotron with radium 226 were manufactured by US Radium Corps.

In France, you could buy a ionotron t.200 for around 20€ in 1960. 
For a total length of 15 cm, the active part had a length of 5 cm. In the 
safety sheet given with the ionotron, it was said that you were at the 
safe distance from the ionotron at 25 cm. Remember though that it was in 
1960...

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