1. Cryogenic Refrigeration Maha Hosain

2. Background Info Cryogenics – science of production and effects of very low temperatures Limit to lowest temp—absolute zero (0K) Cryogenic region  below 120K (-153ºC) Cryogenic Liquids  super-freezing permanent gases to liquid states, ex: oxygen, nitrogen, hydrogen, and helium –Liquid Nitrogen: most easily available –Liquid Helium: lowest temp. <2.17K

3. Cryocoolers Types: Joule- Thomson Brayton Stirling Pulse Tube Gifford- McMahon

4. Applications-MRI Metals and plastics-stronger, durable, elec. resis. dec. (become close to superconductors) Metal wire coiled to produce mag. field w/ no heat or consumption of elec. power, and remains cold

5. Applications Common Extensible Cryogenic Engine Engine comps super-cooled to similar low temps w/ liquid O2 and H2 mixture. As CECE burns its frigid fuels, gas composed of hot steam is produced and propelled out the nozzle creating thrust. The steam is cooled by the cold engine nozzle, condensing and eventually freezing at the nozzle exit to form icicles. Hydrogen light =>take larger spacecrafts to moon

6. Cryonics Freezing body Not acceptable app. of cryogenics Cryosurgery freezing of portions of the body destroy unwanted or malfunctioning tissue

7. References www.kirtland.af.mil/art/index.asp?galleryI D=3978 http://cryogenics.nist.gov/ http://www.youtube.com/watch?v=Pnf0gnf vvJA http://www.youtube.com/watch?v=1R7Ksfo sV