Thursday, May 27, 2010

FLASH Laser Leads to Discovery of New State of Matter

FLASH Laser Leads to Discovery of New State of Matter


Like a scene out of Star Trek, Oxford scientists have created a transparent form of aluminium by bombarding the metal with the world’s most powerful soft X-ray laser. 'Transparent aluminium' previously only existed in science fiction, but the real material is an exotic new state of matter with important implications for planetary science and nuclear fusion.

More @ Daily Galaxy

Wednesday, May 26, 2010

Darwinian spacecraft enine to last twice as long

Darwinian spacecraft engine to last twice as long - space - 24 May 2010 - New Scientist

SPACE agencies may one day have Charles Darwin to thank for the longevity of their spacecraft. The life expectancy of a popular type of ion engineMovie Camera has been almost doubled using software that mimics the way natural selection evolves ever fitter designs.

Electrostatic ion engines are becoming popular in space missions. Instead of relying on burning large amounts of heavy liquid propellant for thrust, they use solar power to ionise a small supply of xenon gas. A high voltage applied across a pair of gridded electrodes sends the positively charged ions rushing at high speed towards the negative electrode. Most ions pass through the grid, generating thrust.


He used evolution-mimicking software (...)

After 100 generations, the GA spawned a geometry/voltage set that boosted the ion engine grid's lifetime to 5.1 years - at least in the simulator (Journal of Propulsion and Power, DOI: 10.2514/1.44358). Factors optimised included grid hole diameter, hole spacing and the thickness of the grids. The engine could be improved further, says Farnell, by evolving the other parts too.

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