I posted a little bit about this late the other night in an open thread. The image above is of Sandia National Laboratories Z Machine. It sits in a room about the size of a high-school gym, & is the world's largest X-ray generator. It releases "80 times the world's electrical power usage for a few trillionths of a second" by supplying power in the multi-terrawatt range.
It works by having 20 million amps of electricity vaporize a small core of vertical tungsten wires (about the size of a spool of thread & finer than human hairs). This reaction creates plasma, which is held in a magnetic field...
...In the past, the machine has been used to aid the computer modeling of nuclear weapons, and to
fire small objects from zero to 76,000 mph in less than a second. The other day it was
reported that the machine did something a tad stranger. During experiments, it encountered some
UNKNOWN force that helped the contained plasma achieve a temperature in excess of
2 Billion Degrees Kelvin.
That's hotter than the Sun...
Scientists working with Sandia's Z machine said the feat also revealed a new phenomenon that could eventually make future nuclear fusion power plants smaller and cheaper to operate than if the plants relied on previously known physics.
"At first, we were disbelieving," said Chris Deeney, head of the project. "We repeated the experiment many times to make sure we had a true result and not an 'Oops'!"
According to
Sandia's Press Release, the results were measured & confirmed by spectrometers & computer modeling. They've also held up to 14 months of additional tests. Among the strange things encountered in the testing...
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 could it come?
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.
They have a
theory on what happened though...
The new achievement -- temperatures of billions of degrees -- was obtained in part by substituting steel wires in cylindrical arrays 55 mm to 80 mm in diameter for the more typical tungsten wire arrays, approximately only 20 mm in diameter. The higher velocities achieved over these longer distances were part of the reason for the higher temperatures.
(The use of steel allowed for detailed spectroscopic measurements of these temperatures impossible to obtain with tungsten.)
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.
Haines' explanation theorizes that Z's magnetic energies create microturbulences that increase the kinetic energies of ions caught in the field's grip. Already hot, the extra jolt of kinetic energy then produces increased heat, as ions and their accompanying electrons release energy through friction-like viscous mixing even after they should have been exhausted.
It is
theorized that...
...The new phenomenon could be exploited in fusion power as a trigger that would set off a controlled nuclear reaction by heating a small amount of deuterium or tritium. It is likely to be more efficient than other proposed methods because it produces higher temperatures while requiring less input energy.
The detailed paper on all of this can be found
here.