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With the heat of a burning sun, a laser pulse has ripped through pure sapphire, heating it faster than any explosion ever recorded, according to a latest report on the website of the Nature.
Physicists from the University of Bordeaux, France, reckon their laser can drive temperature increases of a billion billion (10 to the power of 18) degrees per second, although they could only keep it going for a couple of hundred femto-seconds (with a femto-second being 10 to the power of minus 15 second), thus topping the previous heating-rate record, the report said.
The intense heating power of the laser made miniature fireballs, just thousandths of a millimeter in size, at pressures of 10 terapascals (10 to the power of 13 Pa), about 20 times the pressure at the Earth's core.
Each laser pulse lasted just 200 femto-seconds, enough time for light traveling in a vacuum to zip across the width of a human hair and the sapphire exploded under the heat in just a few femto-seconds, and as the ball of shredded atoms grew it became much less dense, making further heating much less efficient.
To put the pressure in perspective, 10 terapascals (10 to the power of 13 Pa) would be generated by two Great Pyramids of Giza balancing on a CD, or a couple of hundred elephants dancing on the head of a pin.
The intense crush raised the temperature to about half a million Celsius. "You have the same parameters in an atomic explosion," Vladimir Tikhonchuk, a theoretical physicist from the University, was quoted as saying, who added the experiment was a blast.
The success shows that scientists can now simulate the intense condition at the hearts of planets, or possibly even trigger fusion reactions, using a conventional tabletop laser.
According to Tikhonchuk, similar heating rates have probably been generated before in experiments that used laser light to drill holes through materials, but no one had actually worked out the temperatures and pressures involved in those cases.
Editor: Yan
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