The Z-machine at Sandia (New Mexico)
Pollution-free and non-radioactive fusion:
Within reach!
As a reader pointed out, while most people are fixated on the fusion reaction between the two isotopes of heavy hydrogen—deuterium and tritium—very few know that at higher temperatures, other fusion reactions exist (lithium-hydrogen at 500 million degrees and boron-hydrogen at one billion degrees), which produce only helium and generate neither radioactivity nor waste! With the Z-machine (reaching two billion degrees), these temperatures have now been vastly exceeded.
Noted by a reader, a good, recent article on Wikipedia
http://fr.wikipedia.org/wiki/Z_machin
May 26, 2006
May 30: The absence of reaction in the civilian sector
IWe must revisit this entire matter.
In France, the response was virtually nonexistent, aside from a few lines in Science et Vie and Science et Avenir. The initial announcement came from the website
http://www.futura-sciences.com
. Complete radio silence in the mainstream press. Nothing in "Le Monde des Sciences."
Reviewing the facts from their source.
In Google, search:
deeney z machine
Chris Deney is the lead researcher at the Sandia facility (New Mexico) following work initiated over thirty years ago by Gerold Yonas (electron beam fusion, see Pour la science, January 1979). Using this Google search, you'll find various results, but the most reliable is to immediately target the original first-hand information provided by Sandia's communications office. You'll find the link leading to this information release from Sandia's communications department at the following address:
http://www.sandia.gov/news-center/news-releases/index.html
Chich brings us to this:
For specialists,
a description of Sandia's Z-machine:
(if you're not a specialist, skip this boxed section)
The PBFAZ generator is a high-power pulsed generator originally built for ion beam production. In 1996, it was adapted for use with Z-pinch loads and has since been called "Z." It is a conventional current amplification generator using water transmission lines. It consists, from outside to inside, of 36 Marx generators (visible at the outermost radius), followed by a power amplification section using water lines, then a vacuum section. This generator measures 33 meters in diameter and 6 meters in height.
Diagram:
The times shown represent transit times through the various components, each of which is composed of sub-components whose characteristics (transit time, impedance) are given in the small tables associated with them. The spark gaps are either laser-triggered (ls spark gap in the diagram) or self-triggered and located in water (ws spark gaps in the diagram). The table extending along the entire length of the diagram (from Marx generators to the load) below the line elements provides their equivalent capacitances and inductances.
Z's magnetic insulation lines
The Marx generators store
11.4 megajoules
of electrical energy, delivering
4.5 megajoules
to the output of a cascade of water transmission lines that compress the pulse (from the discharge time of a capacitor) into a pulse of
105 nanoseconds.
The output of the water-line stage, separated by spark gaps, feeds magnetic insulation lines via a water/vacuum interface. This interface, of a certain diameter, leads to four stacked cones (note the transition from separate lines to a geometry with rotational symmetry) forming the magnetic insulation lines.
Standard Z convolute
These instrumented lines define four levels, labeled A, B, C, and D. A convolute, shown in the figure above, then sums the currents from the different levels, attempting to minimize losses.
The load can thus be powered by a pulse of 10 to 20 mega-amps for a typical Z-pinch load (i.e., 2 cm long, 2 cm initial radius, with a mass of 4 mg), lasting 105 nanoseconds. The delivered electrical power is around 40 terawatts for such a load.
For diagnostics, we rely on the rapid ionization of neon cells:
Yes, you read that correctly. Billion means billion. Do your own investigation. You'll find a series of communications from Sandia's offices. Until now, there was little to report—the temperatures had been rising slowly. In the paper:
http://www.sandia.gov/LabNews/LN06-04-99/zmachine_story.html
dated June 4, 1999, it reads:
Sandia researchers Chris Deeney (1644), Christine Coverdale (15344), and Victor Harper-Slaboszewicz (15344) pushed the Z machine to new limits last month when they used the world's most powerful X-ray source to test effects of radiation on materials in experiments designed
to mimic the response that would occur near a nuclear explosion.
Clearly, Sandia's experiment is intended to simulate ("mimic") the X-ray burst emitted by a nuclear explosion. At this stage, it is simply an "X-ray source."
During their experiments, the Z machine generated more than 100 kJ of X-rays (kJ stands for kilojoules, a measure of radiated energy) at 4.8 keV (keV for kilo-electron-volt, a unit used to measure the energy spectrum of X-rays). This amount of radiated energy adds significant capability for conducting weapons effects experiments; other sources at this X-ray energy have produced only 10 kJ.
"We are excited that we've reached this milestone," Chris says. "The loss of underground tests limited testing capabilities, but this is the closest to the 'real thing' we've ever achieved with Z-pinches."
Chris, Christine, and Victor, working with Mark Hedemann, Bill Barrett, and Brett Bedeaux (all of 15344), have been using the Z machine and other sources to determine how materials—in this case candidate materials for a neutron generator—respond when exposed to high levels of radiation. When a nuclear weapon detonates, it produces high levels of radiation, which can cause failure in both nearby and distant systems. To prevent failure, weapon components and subsystems designed and built by Sandia must be certified at radiation levels determined by mission needs. Testing materials at high radiation doses and dose rates, combined with advanced computer calculations, is a major step in selecting materials for weapon components.
Information compiled from the Z machine experiments will be used to validate computer modeling. Chris says computer models are being relied on more and more for certification of components through the Accelerated Strategic Computing Initiative (ASCI) Program because appropriate testing environments are not always available.
"If our findings are close to the computer modeling of the same event, it means the modeling is on track, giving us more confidence in what the model is telling us for regimes that we can't test," Chris says.
Since 1992, when full-scale nuclear testing in the United States was halted, scientists have been developing new ways to verify weapons' reliability without actually detonating them. Working at aboveground simulators like Sandia's Saturn and Z, scientists have developed X-ray sources that can be used for testing materials and parts. The p...