July 31, 2009--Oxford University (Oxford, England) and collaborating scientists have created a transparent form of aluminum by bombarding the metal with the world's most powerful soft X-ray laser. 'Transparent aluminum' previously only existed in science fiction, featured in the movie Star Trek IV, but the real material is an exotic new state of matter with implications for planetary science and nuclear fusion, say Oxford University researchers (see also "Ultrafast-laser methods reveal electrons tunneling in real time").
In this week's Nature Physics an international team, led by Oxford University scientists, report that a short pulse from the FLASH laser 'knocked out' a core electron from every aluminum atom in a sample without disrupting the metal's crystalline structure. This turned the aluminum nearly invisible to extreme ultraviolet radiation.
"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, one of the authors of the paper. "Transparent aluminium is just the start. 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."
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. 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. One of the researchers said, "In certain respects, the way it reacts is as though we had changed every aluminium atom into silicon: it's almost as surprising as finding that you can turn lead into gold with light!"
For the full story, go to www.ox.ac.uk/media/news_stories/2009/090727_2.html .
--Posted by Gail Overton, [email protected]; www.laserfocusworld.com.