Anything new?

[gkiing]

Anyone beat -172C cascaded yet? How about an autocascade holding a load below -80c?

Thanks for the updates, I'm around periodically

Keep it cool :D

[Brettbeck]

Nope not really. Don't forget Ricky's -174°c shot was unloaded and only a test... I don't know if he has done any more work on it yet.

[kamongear]

Not to go OT but what is the theoretical limit to how low phase can go?

[potkit]

0k
xD

[n00b 0f l337]

Theoretical low is infinitely small above 0 kelvin. Not 0k itself.
But we can't do that so w/e.
-80C loaded autoc should happen pretty soon (not a cascaded autoc, a autoc straight up), depending on when someone gets the proper gases (r23 and ethylene are most likely good enough).

[kamongear]

Theoretical low is infinitely small above 0 kelvin. Not 0k itself.
But we can't do that so w/e.
-80C loaded autoc should happen pretty soon (not a cascaded autoc, a autoc straight up), depending on when someone gets the proper gases (r23 and ethylene are most likely good enough).


Forgiven me if this is a stupid question but how many stages can a cascade have at a maximum?

Im guessing an infinite number but something's telling me that the gasses we have available would not allow that.

[marru]

Forgiven me if this is a stupid question but how many stages can a cascade have at a maximum?

Im guessing an infinite number but something's telling me that the gasses we have available would not allow that.

You can have as many as you can afford. In theory you can get any gas to condense after a certain number of stages.

[n00b 0f l337]

Well lets see, they condense helium, generally by cascade, and possibly autocascade. Lets see...

r123, r22, r23, r14, r50, nitrogen, and them maybe some more, possibly helium?

[kamongear]

Well lets see, they condense helium, generally by cascade, and possibly autocascade. Lets see...

r123, r22, r23, r14, r50, nitrogen, and them maybe some more, possibly helium?

Yet another question!

How many stages did the cascade with the most stages have?(for CPU cooling of course) 4? 5?

[n00b 0f l337]

I've seen 4-5 I beleive, but a powerful 3 stager could have done the same.

[Blaster]

my autocascade was helding -150w at -97 if i remember right :)

[n00b 0f l337]

If i remember correctly you also have some of the best gas selection I wish I had ;)

[Blaster]

haha i also had to pay for those gases and still am paying the rental for the botles

-80,-75 load its pretty easy with 2stager autocascade

[n00b 0f l337]

Yes I know, take it as a compliment, your works great Blaster.

[[XC] 2long4u]

Well lets see, they condense helium, generally by cascade, and possibly autocascade. Lets see...

r123, r22, r23, r14, r50, nitrogen, and them maybe some more, possibly helium?

How bout hydrogen?

[n00b 0f l337]

Hydrogens quite hard to condense ;)

[potkit]

OT what gases do you own blaster?

[Xeon th MG Pony]

MRI scanners use helium as the coolant, or one of them type of machines.

[Marvin]

:eek: boiling point (approximately -452°F or -269°C):)

[SoddemFX]

Well lets see, they condense helium, generally by cascade, and possibly autocascade. Lets see...

r123, r22, r23, r14, r50, nitrogen, and them maybe some more, possibly helium?

helium?!

Seriously Adam - have you been smoking the 'erb?? :D

Systems to liquify helium aren't vapour compression, they might use a classical or auto cascaded system to drop below inversion and increase production rate in some kind of expansion cycle. Taking a stab in the dark i bet most precoolers are probably fed off straight liquid nitrogen from a dewar and not even closed loop for the precooler.

I don't know what it is but i bet the inversion temperature for helium is pretty damned low, if it's below -210C then i'm not sure how the nitrogen is used.

You won't liquify any practical amount of nitrogen in closed loop with methane preceeding it, especially with what you used in those 2,3 and 4 stages and how you'd have to use them in an autocascade.

I believe that realistically nitrogen is the limit of vapour compression, i believe a workable capacity (for what we want) nitrogen system is possible in six stages but it would be big, realy big.

MRI scanners use liquid helium, helium as a core with an insulating vacuum barrier surrounded by liquid nitrogen. The nitrogen is topped up weekly, the helium is topped up twice a year. My friend is a technician for a uni physics department, he says topping up the helium is the most scary and dangerous part of his job.

Whilst very impressive, R|ckys -174C picture was unloaded, unstable and unworkable. I don't think anyone here has built a safe, loaded system operating much below the -130C region.

Tom