Sandia National Laboratory’s Z machine has produced plasmas of more than 3.5 billion degrees Fahrenheit — temperatures higher than the interiors of stars.
The unexpectedly hot output, if understood and harnessed, might eventually lead to smaller and less costly nuclear fusion plants that could produce the same amount of energy as do larger plants.
The phenomena also may explain how astrophysical entities such as solar flares maintain their extreme temperatures.
The very high radiation output of the plasma-producing Z machine also creates new experimental environments to help validate computer codes responsible for maintaining a reliable nuclear weapons stockpile safely and securely — the principle mission of the Z facility.
Sandia researchers still aren’t sure how the machine achieved the new record. Part of it is probably due to the replacement of the tungsten steel wires with slightly thicker steel wires, which allow the plasma ions to travel faster and thus achieve higher temperatures.
One thing that puzzles scientists is that the high temperature was achieved after the plasma’s ions should have been losing energy and cooling. Also, when the high temperature was achieved, the Z machine was releasing more energy than was originally put in, something that usually occurs only in nuclear reactions.
Sandia consultant Malcolm Haines theorizes that some unknown energy source is involved, which is providing the machine with an extra jolt of energy just as the plasma ions are beginning to slow down.
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’!
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’!
The results, recorded by spectrometers and confirmed by computer models created by John Apruzese and colleagues at Naval Research Laboratory, have held up during 14 months of additional tests.
A description of the achievement, as well as a possible explanation by Sandia consultant Malcolm Haines of Imperial College London, appeared in the Feb. 24 Physical Review Letters.
