Liquid Hydrogen

Basics

• The liquid state of hydrogen
• Useful as a fuel storage method, and as a Cryogen
• Often Abbreviated as LH2
• According to wikipedia "To exist as a liquid, H2 must be cooled below its critical point of 33 K. However, for it to be in a fully liquid state without boiling at atmospheric pressure, H2 needs to be cooled to 20.28 K[3] (−423.17 °F; −252.87 °C)."
• A Common Rocket Fuel (Usually with LOX )
• Neutron Scattering Supposedly Uses LH2
• LH2 is also used for particle physics with Bubble Chambers although they have largely been replacecdd by other technologies

Advantages

• Density of storage

Disadvantages

• It's a Cryogenic Liquid (thus can burn people), and requires intense cooling
• Cryogenic Liquid Boil-Off caused losses, or required active cooling
• Asyphxiation Hazard (although not as bad as heavier gasses, in large enough volumes, it can displace oxygen, thus ventillation and/or sensors are needed

Useful Links

• The Wikipedia Page on Liquid Hydrogen