[Sneap] Electrical isolation and coolant

[Pertti O. Tikkanen]

Paul,

We have been using Shellsol as coolant for our MC-SNICS and Alphatross ion
sources. It has worked well for years in our application. See if Shellsol
properties suit yours. It is an industrial solvent used in cleaning e.g.
motor parts and thus leaks should not be a problem.
When replacing DI water with some other coolant one maybe needs to
consider the difference in the heat transfer properties also.

Regards,
Pertti

-- 
Pertti O. Tikkanen, PhD
Senior Laboratory Manager

Accelerator Laboratory
Department of Physical Sciences
Box 43 (Pietari Kalmin katu 2)
FIN 00014 University of Helsinki

Office:  +358 9 191 50006
Telefax: +358 9 191 50042
Mobile:  +358 40 726 5386

> Paul,
>     You probably used R-113.  We still use it in our Helium source for
> cooling - it is still available but expensive.  I do not know of a direct
> replacement.  I would recommend revisiting the DI water cooling option.
> We have several home built systems in use and they work well.  We have a
> DI
> service company change the canisters every six months and don't have
> conductivity problems.  This is less than $100 as I recall. The highest
> voltage difference is just 200 kV however.
> Regards,
> - Chris
> --
>
> Chris R. Westerfeldt
> Research Scientist / T.U.N.L. Radiation Safety Manager
> Duke University Physics Department &
> Triangle Universities Nuclear Laboratory
> Science Drive, Box 90308
> Durham, NC  27708-0308
> Tel: (919) 660-2600
> Fax: (919) 660-2634
> Email: Cwest at Tunl.Duke.Edu
>
>
>> From: Paul Voytas <pvoytas at wittenberg.edu>
>> Reply-To: Symposium of Northeastern Accelerator Personnel
>> <sneap at tunl.duke.edu>
>> Date: Mon, 12 Nov 2007 14:11:55 -0500
>> To: Symposium of Northeastern Accelerator Personnel
>> <sneap at tunl.duke.edu>
>> Subject: [Sneap] Electrical isolation and coolant
>>
>> Fellow SNEAPers,
>>
>> Short statement of problem:
>> I'm searching for a high resistivity, non-flammable, non-corrosive,
>> non-oil, ozone-safe, low greenhouse effect, fluid to use as coolant in
>> an atmospheric pressure cooling system.
>>
>> Long story:
>> We have an old, small, single ended accelerator we are trying to get
>> reliably in shape for use as a teaching tool. The accel has a rollaway
>> tank and historically, it's been run without the tank on. To get the
>> voltage up and the xray dose down, we run with the tank on now (With SF6
>> at atmospheric pressure).
>> The problem is cooling the up-to-1000W RF source . With the tank off, a
>> squirrel cage fan keeps everything fine. With the tank on, there's a
>> heat exchanger (=radiator) in front of the fan that we can run coolant
>> through. The coolant system is designed to be at atmospheric pressure
>> and historically it used a freon ( 134a maybe?). Due to freon expense
>> and ozone protection issues, I'm now using a perflourinated hydrocarbon
>> (Dow performance fluids 5060 or 5080 ). I'd tried DI water, but the
>> resistivity wasn't high enough--or didn't stay high enough and I don't
>> have an active DIing system. The perfluorinated fluids are not cheap
>> either (and they're pretty bad (good?) greenhouse gases) and I'm worried
>> that the fluorine containing decomposition products (from the high x-ray
>> fluxes) will end up corroding the system. I'd rather not us an oil if I
>> can avoid it because a leak would cause a terrible mess that I'm not
>> sure I could clean off the machine. I'd also rather not use
>> flammables... I think the list is getting pretty short?
>>
>> Question:
>> Does anybody have info on any fluids besides the perfluorinated
>> hydrocarbons that satisfy these (or most of these) constraints?
>>
>> Thanks for any ideas,
>> -Paul Voytas
>>
>> --
>>
>> pvoytas at wittenberg.edu
>> office: 937-327-7823
>> fax:    937-327-6340
>>
>> Physics Department
>> Wittenberg University
>> P.O. Box 720
>> Springfield, OH 45501
>>
>> alt email: pvoytas at uwalumni.com
>>
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>