[Equinox]

  Since im new to the forum I should start by saying hi and give you a short background. Im a programmer/lead machinist for Mogas severe service ball valves.

  I have read the posting rules and have searched the forums for such a topic. I hope that you can forgive me for my ignorance in the matters of chemistry and my form of questions.

Objectives:

 I want to create a a device that reaches top performance of the cold fingers today without the use of a piston. I would like to use a dense liquid to compress the helium. Therefore having no moving parts as associated with cold fingers. The application is for processor cooling and the form factor is "link"
http://www.knightsguildbattalion.com/kgb/datas/users/32-p1010197.jpg
 

 Questions:
 
  Liquid helium can reach temperatures as low as -263C? This temperature is reached by the process of liquid to gas transformation or can it sustain that temperature under constant compression?

  Assuming that it reaches those temperatures from returning to gaseous state is there a pressure/vacuum rating to reach the lowest possible temperature?

What is a reasonable compression rate in psi for helium to compress to its most dense state?

What is the compression ratio for Helium from liquid to solid? I was able to find nitrogen's 694 to 1 if that example helps explain my question.

I have several questions pertaining to this matter I just don't want to wear out my welcome with my first post:)

Sincerely
Equinox

[Borek]

I am not sure I understand your questions. Do you know what adiabatic compression is, pV=nRT, what a condensation heat is?

As far as I know there is no solid helium and there is no lower limit on the liquid helium temperature other than absolute zero.

[AWK]

Solid helium exists below 1.1 K over 26 atm.

http://ltl.tkk.fi/research/theory/helium.html
http://darkwing.uoregon.edu/~rjd/vapor1.htm

[Borek]

Solid helium exists below 1.1 K over 26 atm.

Heh, my knowledge was limited to lower pressures

Thanks for sharing.

[Equinox]

I am not sure I understand your questions. Do you know what adiabatic compression is, pV=nRT, what a condensation heat is?

I am not familiar with adiabatic compression. pV=nRT? I wouldn't have the foggiest idea. I am a machinist with no background in chemistry. I would like to think that I could follow you through the most detailed descriptions but alas, that is just not a reality for me. I got half way through chemistry cliff notes before they lost me though. I always say things are relative to ones experiences.

As far as I know there is no solid helium and there is no lower limit on the liquid helium temperature other than absolute zero.

  The statement from liquid to solid was a typeO. I ment to say liquid to gas. Sorry for the miss leading info. Has been my experience with LN2 and exotic Freon's like 507A that the more compression and larger evaporation capacitor the colder you can achieve. in the case of Freon's we are achieving -140 C by cascading the systems "multiple compressors". I thought 0 Kelvin was absolute.

Solid helium exists below 1.1 K over 26 atm.

http://ltl.tkk.fi/research/theory/helium.html
http://darkwing.uoregon.edu/~rjd/vapor1.htm

found 1 other also
http://www.yutopian.com/Yuan/HeII.html

Excellent links:) enjoyed them and has been able to give me direction to my questions. However a bit over my head. <<--I hate saying that "pride:(". I would like a mulligan on the questions. The question I should start with is what Helium isotope has the easiest ability to phase change and control.

 In one of your links it states that

"4He is the more common isotope of helium. The figure shows the phase diagram of 4He at low temperatures. 4He remains liquid at zero temperature if the pressure is below 2.5 MPa (approximately 25 atmospheres). The liquid has a phase transition to a superfluid phase, also known as He-II, at the temperature of 2.17 K (at vapor pressure). The solid phase has either hexagonal close packed (hcp) or body centered cubic (bcc) symmetry."

  Should I be directly looking into 4He properties? I have found several similarities between this and cold fingers today including minimum temperatures of 2.17 K. I assume now im targeting a superfluid state? this is where the low temperatures occur? Would that mean that it is perpetually creating that low temperature as long as I can keep it at a superfluid state. Can I control the superfluid state simply by compression? Would the heat from the atmosphere/processor play a part in how many times I would have to cycle the superfluid state for reaching and sustaining such low temperatures.

  If your willing I can create a prototype drawing in whatever extension ".DWG" you want of the actual design of the cooling head itself. Not all the pumps and other related equipment for it to be much easier to describe what im trying to accomplish.

Edit: Im not asking for your help, im begging. If it takes finance to open lines of communication I am willing to do that. The pumps, lines, and material I can do along with all prototyping. I am surrounded by engineers willing to help with that aspect. However you have the knowledge most necessary for this to begin. Even if it was a referral to a consultant firm. Any help would be appreciated.

PS:

Sincerely
Equinox