Oh, The Transparent Aluminum Thing? Here's The Story...
by
LeRoy_Was_Here
07/28/2009, 6:20 PM #
And an interesting one it is, too:
Transparent Aluminum Is ‘New State Of Matter’
Experimental
set-up at the FLASH laser used to discover the new state of matter.
(Credit: Image courtesy of University of Oxford)
ScienceDaily (July 27, 2009)
— 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,
featuring 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.
In the journal 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 aluminium atom in a
sample without disrupting the metal’s crystalline structure. This
turned the aluminium 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 discovery was made possible with the development of a new source
of radiation that is ten billion times brighter than any synchrotron in
the world (such as the UK’s Diamond Light Source). The FLASH laser,
based in Hamburg, Germany, 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 aluminium
turned transparent.
Whilst 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.
Professor Wark added: ‘What is particularly remarkable about our
experiment is that we have turned ordinary aluminium into this exotic
new material in a single step by using this very powerful laser. 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 aluminium atom into silicon: it’s almost as surprising as
finding that you can turn lead into gold with light!’
The researchers believe that the new approach is an ideal way to
create and study such exotic states of matter and will lead to further
work relevant to areas as diverse as planetary science, astrophysics
and nuclear fusion power.
A report of the research, ‘Turning solid aluminium transparent by
intense soft X-ray photoionization’, is published in Nature Physics.
The research was carried out by an international team led by Oxford
University scientists Professor Justin Wark, Dr Bob Nagler, Dr Gianluca
Gregori, William Murphy, Sam Vinko and Thomas Whitcher.
