Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Cooled Grids
Date: Oct 19, 3:30 pm
Poster: Richard Hester

On Oct 19, 3:30 pm, Richard Hester wrote:

Another candidate for grid cooling might be He, which would be comparable in viscosity to H2, but without the fire/explosion hazards.
You want to be careful working with high pressure/high temperature systems. My father was in shipfitting/damage control in his Navy days, and he told me stories about looking for high pressure steam leaks with a broom. When the broom came back with a hunk missisng, you had found your leak. Cheaper and less traumatic than using fingers..... As another cautionary example, you might want to consider that a high pressure water jet can be used for cutting materials of all sorts.
Richard Hester

>>>The limit on temp I would think would be about 100 degrees C as flash steam would occur much above that point. Maybe even more pressure.
>I think that pressurized water might be the best bet, for liquids. easy to handle, etc. the burst strength on small tubing is quite high (6000 psi). Even if you ran it to 1000C, you are looking at 1000 psi kinds of pressures.. This is no problem (hey, you've got a bottle of D2 at 3000 psi there)... Water is nice because it is an insulator (that grid is going to be a several 10's of kV relative to ground, and I'd hate to come up with a scheme to insulate molten metal.
>I did a quick check on N2 gas, and it doesn't come off too well in comparison to water. I need to check H2, which has a very low viscosity.