image
Physics Forums Logo
image
image
* Register * Upgrade Blogs Library Staff Rules Mark Forums Read
image
image   image
image

image Liquid Nitrogen vs. Liquid Helium Share It Thread Tools Search this Thread image
Old Oct3-05, 08:07 PM                  #1
gapgirl1010

gapgirl1010 is Offline:
Posts: 21
Question Liquid Nitrogen vs. Liquid Helium

The reason that liquid nitrogen temperature superconductors are important is that liquid nitrogen costs less than liquid helium. New technologies to store liquid helium have been developed in the last year. This has brought the cost of liquid helium down. how might this affect the direction of the field?

PLease help me!
  Reply With Quote
Old Oct3-05, 09:25 PM                  #2
gapgirl1010

gapgirl1010 is Offline:
Posts: 21
Question Temperature in Kalvins

Hi, the absolute zero is -173 right?

This is equal to 0 Kalvins right?
So which is a better superconducter?
Liquid Helium @ 3 K
Liquid Nitrogen @ 77K

PLease HelP!
  Reply With Quote
Old Oct3-05, 09:42 PM                  #3
z-component
 
z-component's Avatar

z-component is Offline:
Posts: 483
The unit is called Kelvin, and absolute zero is 0 Kelvin or -273 degrees Celcius.
  Reply With Quote
Old Oct3-05, 09:43 PM                  #4
killerinstinct

killerinstinct is Offline:
Posts: 87
Absolute zero is characterised as 0 kelvins or 0 degrees Rankine, −273.15 °C, −459.67 °F.
i'm not a chemist, but i bash chemists for their incompetence.
I would suppose liquid nitrogen...
  Reply With Quote
Old Oct3-05, 09:47 PM                  #5
Grogs

Grogs is Offline:
Posts: 219
Originally Posted by gapgirl1010
Hi, the absolute zero is -173 right?

This is equal to 0 Kalvins right?
So which is a better superconducter?
Liquid Helium @ 3 K
Liquid Nitrogen @ 77K

PLease HelP!
It's -273.15 degrees celcius. Celcius to kelvin is an easy conversion since 1 degree celcius is the same as one kelvin, so T(kelvin) = T(celcius) + 273.15 degrees.

Understand first that Helium and Nitrogen aren't superconductors. They're used to cool the superconductors. Once you drop the temperature of the superconductive substance low enough, the internal resistance drops to near zero (it becomes a superconductor.) As far as what's going on with the superconductive material, they're both going to behave the same way once they reach the critical temperature.

The main difference is going to be cost. With it's higher boiling point, liquid nitrogen is *much* cheaper than liquid helium. The superconductor with the higher critical temperature will be more attractive from that perspective.
  Reply With Quote
Old Oct3-05, 09:56 PM                  #6
gapgirl1010

gapgirl1010 is Offline:
Posts: 21
OKay, I get that thanks!
  Reply With Quote
Old Oct3-05, 10:16 PM       Last edited by Viper2838; Oct3-05 at 10:17 PM.. Reason: spelling mistake            #7
Viper2838

Viper2838 is Offline:
Posts: 28
Well, first look at the boiling point of each liquid. Nitrogen condenses at 77 K while Helium condenses at 4.22 K.
It becomes increasingly expensive to cool something down. The closer to absolute zero (0K) something is cooled, the more it will cost.
Now, I believe that most superconductors must be chilled down below roughly 60 K. Most of the research today has been focusing on creating superconductors that can be cooled by Nitrogen.
Given this information and the information you already stated, how do you think the direction of the field will be affected?
~Steve
  Reply With Quote
Old Oct3-05, 10:47 PM                  #8
Integral

PF Mentor
 
Integral's Avatar

Integral is Offline:
Posts: 5,589
Blog Entries: 9
I have merged the 2 He/Hy threads, one is enough.
  Reply With Quote
image image
Reply
Thread Tools


Similar Threads for: Temperature in Kalvins
Thread Thread Starter Forum Replies Last Post
Kelvin Temperature - Celsius Temperature Change Davidrdguez General Physics 7 Feb6-08 11:34 PM
temperature miss photon Classical Physics 15 Dec9-07 08:54 PM
Highest possible temperature = Planck temperature? Lisa... Classical Physics 3 Apr3-06 12:53 PM
temperature king_2005 Introductory Physics 0 Sep15-05 12:39 AM
Temperature change, temperature derivative of material? Hoang Duc Minh General Physics 0 Jun30-04 06:38 PM

Powered by vBulletin Copyright ©2000 - 2009, Jelsoft Enterprises Ltd. © 2009 Physics Forums
Sciam | physorgPhysorg.com Science News Partner
image
image   image