MAKE READY FOR
THOR — Sandia National Laboratories technician Eric Breden
installs a
transmission cable on the silver disk that is the new pulsed-power machine’s
central powerflow
assembly. (Photo by Randy Montoya)
(January 5, 2015) Sophisticated
features may influence eventual Z-machine rebuild
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.
Sandia National
Laboratories technician Tommy Mulville installs a gas exhaust line for a
switch at Thor’s
brick tower racks. In the background, beyond the intermediate support towers,
technician Eric
Breden makes ready an electrical cable for insertion in the central power
flow assembly.
(Photo by Randy Montoya)
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.