Thursday, March 09, 2006

Z machine exceeds two billion degrees Kelvin hotter than the interiors of stars

Z machine hotter than the interiors of stars: "Sandia’s Z machine has produced plasmas that exceed temperatures of 2 billion degrees Kelvin — hotter than the interiors of stars. The unexpectedly hot output, if its cause were understood and harnessed, could eventually mean that smaller, less costly nuclear fusion plants would produce the same amount of energy as larger plants.

“At first, we were disbelieving,” says Sandia project lead Chris Deeney. “We repeated the experiment many times to make sure we had a true result and not an ‘Ooops’!” (blah, blah - they verified the result. So...)

First, the radiated x-ray output was as much as four times the expected kinetic energy input. Ordinarily, in non-nuclear reactions, output energies are less — not greater — than the total input energies. More energy had to be getting in to balance the books, but from where?

Second, and more unusually, high ion temperatures were sustained after the plasma had stagnated — that is, after its ions had presumably lost motion and therefore energy and therefore heat — as though yet again some unknown agent was providing an additional energy source to the ions.

Sandia’s Z machine normally works like this: 20 million amps of electricity pass through a small core of vertical tungsten wires finer than human hairs. The core is about the size of a spool of thread. The wires dissolve instantly into a cloud of charged particles called a plasma.

The plasma, caught in the grip of the very strong magnetic field accompanying the electrical current, is compressed to the thickness of a pencil lead. This happens very rapidly, at a velocity that would fly a plane from New York to San Francisco in several seconds.

At that point, the ions and electrons have nowhere further to go. Like a speeding car hitting a brick wall, they stop suddenly, releasing energy in the form of X-rays that reach temperatures of several million degrees — the temperature of solar flares.

Haines theorized that the rapid conversion of magnetic energy to a very high ion plasma temperature was achieved by unexpected instabilities at the point of ordinary stagnation: that is, the point at which ions and electrons should have been unable to travel further. The plasma should have collapsed, its internal energy radiated away. But for approximately 10 nanoseconds, some unknown energy was still pushing back against the magnetic field."

Fuck me! Inexplicable in terms of normal science? An experiment offering a paradigm shift? Possibly, whatever that means. This offers the chance of small fusion reactors that actually work - saving nuclear power as a possible alternative energy source! Brilliant!

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