Re: Tandem accel question

[LIPTONW@detroitedison.com]

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Any accelerator radiation safety program which involves interlocks must also 
have provisions for periodic testing and for frequent operablity checks.  Most 
interlocks are easy to bypass, and accelerator experimenters generally have 
the knowledge to bypass them in a way that is not readily detected.   
 
Interlocks which interface with radiation monitors are especially tricky, 
since these can be bypassed at either the interlock itself or at the monitor; 
e.g., changing the hi voltage for the monitor can effectively negate the 
interlock without being apparent.   
The bottom line is that interlocks do not take the place of effective 
administrative controls and, most importantly, management support for the 
safety program. 
 
Bill Lipton 
The opinions expressed are solely mine. 



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Received: 03 May 1996 09:58:30                    Sent: 03 May 1996 08:53:24
From:"radsafe@romulus.ehs.uiuc.edu" <radsafe@romulus.ehs.uiuc.edu>
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Subject: Tandem accel question
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Keep in mind the currents being considered: 1 and 30 micro-amps.
These are very small currents and, although in the low MeV,
I would expect no significant rad levels. At IBM Watson Lab
we installed a 1 MeV Pellatron and have the end stations and
control console in the same room. The vendor did wrap some
lead around the tank and I had area monitors up for over a
year with nothing but background. Think of it as a high-end
ion implanter. I did require area gamma and neutron monitors
be installed, interlocked to the accel, and set to some
low trip point like 1 - 2 mrem/hr.

We did build a shielded room for some neutron work. The
researchers could accel He++ into a Be foil. This room
had the interlocked door. The tandem accel itself was
basically a non-rad generator so the main room only had a
special badge reader on it.

Hope this helps.

Jeff
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Jeffrey Leavey                          certhp@vnet.ibm.com
X-ray Lithography Program                         IBM Corp.
914-892-4595                       East Fishkill, NY  12533
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