A new Sandia National Laboratories accelerator called Thor is expected to be 40 times more efficient than Sandia’s Z machine, the world’s largest and most powerful pulsed-power accelerator, in generating pressures to study materials under extreme conditions.
“Thor’s magnetic field will reach about one million atmospheres, about the pressures at Earth’s core,” said David Reisman, lead theoretical physicist of the project.
Though unable to match Z’s 5 million atmospheres, the completed Thor will be smaller — 2,000 rather than 10,000 square feet — and will be considerably more efficient due to design improvements that use hundreds of small capacitors instead of Z’s few large ones.
Remarkable structural transformation
This change resembles the transformation of computer architecture in which a single extremely powerful computer chip was replaced with many relatively simple chips working in unison, or to the evolution from several high-voltage vacuum tubes to computers powered by a much larger number of low-voltage solid-state switches.
A major benefit in efficiency is that while Z’s elephant-sized capacitors require large switches to shorten the machine’s electrical pulse from a microsecond to 100 nanoseconds, with its attendant greater impact, the small switches that service Thor’s capacitors discharge current in a 100-nanosecond pulse immediately, obviating energy losses inevitable when compressing a long pulse.
The new architecture also allows finer control of the pulse sent to probe materials.
Toward a more perfect pulse shape
Said Reisman, “Individual cables from pairs of capacitors separate our signals. By combining these signals in any manner we choose, we can tailor very precise pulses of electrical current.”
Tailored pulse shapes are needed to avoid shocks that would force materials being investigated to change state. “We want the material to stay in its solid state as we pass it through increasing pressures,” he said. “If we shock the material, it becomes a hot liquid and doesn’t give us information.”
Another advantage for Thor in such testing is that each capacitor’s transit time can be not only controlled to the nanosecond level but isolated from the other capacitors. “In 30 seconds on a computer, we can determine the shape of the pulse that will produce a desired compression curve, whereas it takes days to determine how to create the ideal pulse shape for a Z experiment,” Reisman said.
Furthermore, because Thor can fire so frequently — less hardware damage per shot requires fewer technicians and enables more rapid rebooting — researchers will have many more opportunities to test an idea, he said.
But there’s more at stake than extra experiments or even new diagnostics. There’s testing the efficiency of a radically different accelerator design.
Thor’s shoebox-sized units, known as “bricks,” contain two capacitors and a switch. The assembled unit is a fourth-generation descendant of a device jointly developed by Sandia and the Institute of High-Current Electronics in Tomsk, Russia, called a linear transformer driver (LTD). The original LTD units, also called “bricks,” had no cables to separate outputs, but instead were linked together to add voltage as well as current. (Because Thor’s bricks are isolated from each other, they add current but not voltage.)
Everything depends upon adding bricks. Sandia is building Thor in stages and already has assembled materials. Two intermediate stages are expected in 2016. These will comprise 24 bricks (Thor 24) and 48 bricks (Thor 48). “These are ‘first-light’ machines that will be used for initial experiments and validation,” Reisman said.
Thor 144, when completed, should reach 1 million atmospheres of pressure.
The Latest on: Pulsed-power accelerator
via Google News
The Latest on: Pulsed-power accelerator
- Georgia Tech, Lockheed Martin to develop rugged radomes and windows to withstand rigors of hypersonic flighton February 19, 2021 at 12:30 am
ARLINGTON, Va. – U.S. military researchers are asking two defense contractors to develop rugged RF radomes and infrared windows able to withstand the severe heat, shock, and vibration of ...
- Can super-Earth interior dynamics set the table for habitability?on February 9, 2021 at 2:20 pm
magnetically-driven pulsed power machine (Sandia's Z Pulsed Power Facility) to directly shock a high-density sample of bridgmanite—a high-pressure magnesium silicate that is believed to be ...
- Pioneering the petawatt regime at ELI-Beamlineson January 27, 2021 at 7:00 am
Additionally, a pulsed-power system to drive those diode arrays would also ... For example, laser wakefield acceleration can create high-energy particle and photon beams equivalent to those created by ...
- DARPA asks industry for rugged mobile electron linear accelerator for bomb disposal and package inspectionon January 25, 2021 at 2:30 am
ARLINGTON, Va. – U.S. military researchers are asking industry to develop a rugged, compact and deployable electron linear accelerator for remote bomb disposal and detonation, mobile imaging and ...
- The Review of scientific instrumentson January 22, 2021 at 4:00 pm
Erratum: "Invited Review Article: 'Hands-on' laser-driven ion acceleration: A primer for laser-driven source development and potential applications" [Rev. Sci. Instrum. 87, 071101 (2016)].
- Sandia Fellow wins fusion awardon January 16, 2021 at 4:00 pm
Among Matzen’s achievements was converting the Sandia particle-beam fusion accelerator to a pulsed-power machine, known as “Z.” The “Z” machine has provided insights into the properties ...
- RIKEN SPring-8 Center Accelerator Research and Development Groupon October 15, 2019 at 2:49 am
"A stable pulsed power supply for multi-beamline XFEL operations" Review ... "Time-interleaved multi-energy acceleration for an XFEL facility", Physical Review Special Topics Accelerators and Beams 16 ...
- DPP Meeting Features Latest Advances in Plasma Physics Researchon May 2, 2016 at 1:52 am
By comparison, the Stanford Linear Accelerator Center (SLAC ... conditions on Sandia’s large pulsed-power Z machine which uses water as both an insulator and a breakdown dielectric for switching. The ...
- MUNITIONS LISTon March 31, 2016 at 4:42 am
Note 1 Directed energy weapon systems controlled by this Item include systems whose capability is derived from the controlled application of: "Lasers" of sufficient continuous wave or pulsed power 10 ...
- High Energy Density & Plasma Physicson November 4, 2014 at 6:13 am
The Physics Department has a number of distinctive research facilities that enhance the research activities in plasma physics and high energy density science including a 2 TW z-pinch accelerator, a ...
via Bing News