Re: [CAD_CAM_EDM_DRO] High pressure water jet (Lasers)

e.heritage@... wrote:

> Jon,
>
> I thought that as well to begin with. But in most really big industrial
> sized CO^2 lasers the medium is usually something like 70% He with other
> gases for better lasing actions, N being one of them.

I went out to a shop where a guy had an essentially home-made CO2
laser cutting rig. It was only 50 W, I think, and was used for cutting
plastics mostly. I think it could cut some metals if they were very thin.
I'm awfully sure that the gas supply was high purity CO2, with nothing
added.

> I'm not sure but
> doesn't He have a lower freezing point than N?

Yes, around 4 K at atmospheric pressure. Nitrogen is 77 K. Oh, sorry,
you CANNOT freeze Helium. It goes into a superfluid state around
1.3 K, but it will not solidify, no matter how cold you go. So, those temps
above are the boiling points.

Jon