Target cooling water system isolation?

For the design and construction details of ion guns, necessary for more advanced designs and lower vacuums.
John Futter
Posts: 1455
Joined: Thu Apr 22, 2004 2:29 am
Real name: John Futter
Contact:

Re: Target cooling water system isolation?

Post by John Futter » Tue Feb 02, 2010 9:39 am

All I know is that we buy this stuff from NEC

transformer oil should be more than ok

User avatar
Doug Coulter
Posts: 1312
Joined: Sun May 27, 2007 7:18 pm
Real name: Doug Coulter
Location: Floyd, VA, USA
Contact:

Re: Target cooling water system isolation?

Post by Doug Coulter » Tue Feb 02, 2010 3:18 pm

Well, by that definition quartz is also a conductor, and so is high vacuum -- put a big field on either and current will flow. It's always a matter of degree, order of magnitude. Look at ohms per sq of really pure water and it looks decent -- problem is keeping it that way. The big Z pinch machine is water insulated. So....obviously it can work as an insulator as long as you keep ionic stuff out of it. I was kind of surprised how good it is when I went to use cataphoresis to put Y2O3 on some filaments to make them emit electrons better, using plain old store distilled water -- even in a not that clean beaker with whatever contamination the Y2O3 had in it,it took hundreds of volts to get it to draw current. But let that sit on the bench a couple of days and get some dust in it, it becomes a much better conductor.

The other problem with water is lubricity -- it stinks as a lube (great as a cutting fluid) so pumps that have rubbing parts need not apply. No gears etc, have to go centrifugal and even then if the pump is not designed for it, the seals and bearing fail quickly. Best I'd seen for that was a magnetic coupled pump with graphite bearing on alumina for that part. Lived forever.
Why guess when you can know? Measure!

DaveC
Posts: 2346
Joined: Sat Jun 30, 2001 5:13 am
Real name:

Re: Target cooling water system isolation?

Post by DaveC » Tue Feb 02, 2010 10:39 pm

Yup - Transformer oil IS the coolant in.... um.... transformers.

Can be a bit ornery, if your outside temps are -40F or something, but if it's warm, it flows real nicely.


Dave Cooper

Linda Haile
Posts: 230
Joined: Mon Jan 04, 2010 9:28 pm
Real name:

Re: Target cooling water system isolation?

Post by Linda Haile » Wed Feb 03, 2010 7:38 pm

If you are still considering water, look at 12 volt bilge pumps, they are cheap and available in lots of different sizes (litres per hour). I think RULE is the most common make. They are also mostly plastic.

User avatar
Doug Coulter
Posts: 1312
Joined: Sun May 27, 2007 7:18 pm
Real name: Doug Coulter
Location: Floyd, VA, USA
Contact:

Re: Target cooling water system isolation?

Post by Doug Coulter » Wed Feb 03, 2010 7:55 pm

And, if you can find one the right size, they really do rule ;~} I've used them here on the farm with a large tractor towable tank to get lots of water out of streams etc. They are very power efficient. They may not make enough head for your application, but these were done by guys who really understand the hydrodynamics of water, unlike nearly all other water pumps. They are certainly one of the best for pre pressurizing another non-self-starting pump from a sump of some kind Good thought, Lyn.

Seems like they may also handle some of the other fluids mentioned above, too. As an aside, I've had these frozen solid in the bottom of a tank, no damage once things thawed. They are better than they look.
Why guess when you can know? Measure!

Linda Haile
Posts: 230
Joined: Mon Jan 04, 2010 9:28 pm
Real name:

Re: Target cooling water system isolation?

Post by Linda Haile » Thu Feb 04, 2010 8:04 pm

They are a lot more powerful than they look, and they will maintain a head. The reason I suggested them is if you need to float a 12 volt system in a HV circuit they will take some beating.

User avatar
Doug Coulter
Posts: 1312
Joined: Sun May 27, 2007 7:18 pm
Real name: Doug Coulter
Location: Floyd, VA, USA
Contact:

Re: Target cooling water system isolation?

Post by Doug Coulter » Thu Feb 04, 2010 8:57 pm

They are very efficient, true, but only meant to get water from a bilge to over the side, or at least the ones I've seen, up to the 1000gph range. At 10' head (about 5psi) the flow drops to zero. I used to use them daily to get our drinking water out of a rather remote spring, and had to dig a road to get the tractor closer because of that. Takes more than 5 psi pressure drop to run *most* cooling systems but great for priming a more powerful pump you can't put into the water like you can one of these.

Think one of those garden fountain pumps, on steroids, and you're about there. Very low power drain for the amount of water moved.
Why guess when you can know? Measure!

Linda Haile
Posts: 230
Joined: Mon Jan 04, 2010 9:28 pm
Real name:

Re: Target cooling water system isolation?

Post by Linda Haile » Thu Feb 04, 2010 9:04 pm

I'm not going to press the point, but the larger ones do create some pressure. depends how much flow you require. Well worth some experimentation. I respect your comments Doug.

lutzhoffman
Posts: 188
Joined: Tue Dec 08, 2009 1:59 am
Real name:

Re: Target cooling water system isolation?

Post by lutzhoffman » Wed Feb 10, 2010 2:27 am

Fluorocarbon fluid period is the best I think , either fluorinert, or better the newer Galden line of fluids, with just about any reasonable temperature tailored product being available. They insulate like crazy, and they are totally stable, and non-toxic. Many commercial accelerators use Galden fluids to cool the terminal ion source, so it will isolate into the MEV range. The semiconductor industry is also a heavy user.

I have some Galden 110 which is like "fluorocarbon water" it boils at 110C, but the viscosity is very low so it pumps fast, and it is compatible with everything except, get this: Fluorocarbon polymers which it makes swell. On the other hand cheap rubber or poly tubing is just fine. Check out the Galden web site:

http://www.solvaysolexis.com/products/b ... 2-0,00.htm

You can often find it for a reasonable price on ebay. There was some HT200 the last time I looked with "best offer"

Post Reply