Chapter Eight : Low Temeprature physics (Cryogenics)

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<td colSpan=2><SPAN style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 'Arabic Transparent'; TEXT-ALIGN: justify"><FONT color=indigo>Basic Concepts:

- Low temperature physics deals with the study of materials at temperature near absolute zero.
- Van de Waal's effect expresses the mutual interaction between molecules and is different from chemical interaction between atoms which leads to formation of molecules.
- The mechanism for achieving very low temperature depnds on drawing energy from the material, this may be done by putting the material to be cooled in contract with a cooler material such as liquified gas.

Super fluidity:
- Somliquefied gases can flow without resistance or without friction at temperatures close to absolute zero. Helium liquid is a superfluid its viscosity vanishes. It can also flow up along the walls of the container againest gravity and friction and has low specific heat.