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7/30/09

Scientists Claim New State of Matter Created


Scientists claim to have created a form of aluminum that's nearly transparent to extreme ultraviolet radiation and which is a new state of matter.
It's an idea straight out of science fiction, featured in the movie "Star Trek IV."
The work is detailed in the journal Nature Physics.
The normal states of matter are solid, liquid and gas, and a fourth state, called plasma, is a superheated gas considered more exotic. Other experiments have created strange states of matter for brief periods. This one, too, existed only briefly.
To create the new, even more exotic stuff, a short pulse from a laser "knocked out" a core electron from every aluminum atom in a sample without disrupting the metal's crystalline structure, the researchers explain.
''What we have created is a completely new state of matter nobody has seen before," said professor Justin Wark of Oxford University's Department of Physics.
"Transparent aluminum is just the start," Wark said. "The physical properties of the matter we are creating are relevant to the conditions inside large planets, and we also hope that by studying it we can gain a greater understanding of what is going on during the creation of 'miniature stars' created by high-power laser implosions, which may one day allow the power of nuclear fusion to be harnessed here on Earth."
Fusion is a dream of scientists who would create cheap and plentiful power by fusing atoms together, as opposed to nuclear fission that generates electricity today.
The discovery was made possible with a high-powered synchrotron radiation generator called the FLASH laser, based in Hamburg, Germany. It produces extremely brief pulses of soft X-ray light, each of which is more powerful than the output of a power plant that provides electricity to a whole city.
The Oxford team, along with their international colleagues, focused all this power down into a spot with a diameter less than a twentieth of the width of a human hair. At such high intensities the aluminum turned transparent.
While the invisible effect lasted for only an extremely brief period - an estimated 40 femtoseconds - it demonstrates that such an exotic state of matter can be created using very high power X-ray sources.
"What is particularly remarkable about our experiment is that we have turned ordinary aluminum into this exotic new material in a single step by using this very powerful laser," Wark said. "For a brief period the sample looks and behaves in every way like a new form of matter. In certain respects, the way it reacts is as though we had changed every aluminum atom into silicon: it's almost as surprising as finding that you can turn lead into gold with light."
LiveScience.com

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