PDA

View Full Version : Temperature Conditions of a Supernova Recreated in UK Laboratory



Fraser
2008-May-30, 12:00 AM
Scientists are one step closer to attaining the ultimate goal: producing temperatures high enough to sustain fusion, the reaction that powers our Sun and the possible future for global energy production. Researchers at the Rutherford Appleton Laboratory in Oxfordshire, UK, have attained temperatures higher than the surface of the Sun, 10 million Kelvin (or Celsius), [...]

More... (http://www.universetoday.com/2008/05/29/temperature-conditions-of-a-supernova-recreated-in-a-uk-laboratory/)

GOURDHEAD
2008-May-30, 02:32 AM
From the link:
Vulcan blasted its target with the one petawatt laser beam for a mere 1 picosecond (one million millionths of a second). This may seem miniscule, but this microscopic period of time allowed the target material to be heated to the 10 million Kelvin.
Isn't a million millionths of anything, one of them? How was the 10 million Kelvin actually measured? What was the target material? Can thermal inertia be overcome in a picosecond? More and more scientific reporting seems to follow the example of the carelessness and loose discipline employed by the global warming cult.

trinitree88
2008-May-30, 02:36 PM
From the link:Isn't a million millionths of anything, one of them? How was the 10 million Kelvin actually measured? What was the target material? Can thermal inertia be overcome in a picosecond? More and more scientific reporting seems to follow the example of the carelessness and loose discipline employed by the global warming cult.

Gourdhead. I'll answer one of them. Temperature. Usually the target is a solid pellet of a likely fusion chain...like lithium deuteride, or some such. When it ionizes, it gives off a spectrum similar to the hydrogen spectrum, with fixed energy levels. At low temperatures, the spectral lines are sharp, as only quantized transitions occur. But, when the motion of the atoms is high, then there is Doppler broadening of the spectral lines due to some atoms moving rapidly in all directions. Plasma physicists have calibrated the Doppler broadening.....and a new broadening never before seen, means they have achieved a new world record temperature. (Prof. Bruno Coppi, Plasma Fusion Lab.. MIT tour). Pete

The same effect is used astrophysically to detect the periodic shift of starlight, revealing planetary companions. Neat.

GOURDHEAD
2008-May-31, 02:50 AM
At low temperatures, the spectral lines are sharp, as only quantized transitions occur. But, when the motion of the atoms is high, then there is Doppler broadening of the spectral lines due to some atoms moving rapidly in all directions. Plasma physicists have calibrated the Doppler broadening.....and a new broadening never before seen, means they have achieved a new world record temperature. (Prof. Bruno Coppi, Plasma Fusion Lab.. MIT tour). Pete I'm astonished that the diagnostic characteristics of spectral line broadening lends itself to credible analysis during a pico-second where the volume of the sample is "quite" small. How many atoms are usually involved in such thermal excitations?