CLASS OF 2015
WORLD-GENERATION FEBRUARY/MARCH 2015 V.27 #1
20
PPPL is looking forward to reopening
the National Spherical Torus Experiment
after “stellar” progress in the $94 million
upgrade of the facility that should allow it to
be completed this year, according to
Stewart Prager.
NSTX-U is the experiment at the heart
of PPPL’s research activities and will make
the facility the most powerful tokamak of
its type in the world. The two main compo-
nents of the upgrade, Prager said, are the
center magnet or center stack, and a sec-
ond neutral beam that injects neutral atoms
into the ionized gas or plasma to heat the
plasma to temperatures of about 100 million
degrees Centigrade. Those components will
double the current, double the heat and
quadruple the duration of the plasma.
“We’re building a scientific tool for the
country and the Laboratory and there’s
been great progress over the last year,”
Prager said. “To date, every technical chal-
lenge has been met and there have been
many of them.”
The neutral beam is in place in the
NSTX and the center stack was inserted
into the vacuum vessel of the device in
October. The center stack magnet is really
two magnets in one: copper bars that go
straight up and down create one magnetic
field and a coil around the center stack is a
second magnet that drives a current
through the plasma. It was constructed in
four quadrants, which were then assembled
and insulated.
“This requires incredible engineering
and craftsmanship and it’s gone extremely
successfully,” Prager said. “We’re 85 per-
cent in completion of the upgrade.”
The U.S. Department of Energy has
strongly supported the NSTX-U project
despite the ups and downs of federal fund-
ing, Prager said. “This is a fantastic result
for this year and I hope next year we’ll be
talking about the initial experiments on the
NSTX-U,” Prager said.
The NSTX-U will allow researchers to
produce “a sustained high pressure plas-
ma” over the next decade, Prager said.
Researchers also hope to discover “novel
solutions” for the plasma material interface,
the material inside the machine facing the
plasma. That will be an essential task not
only for PPPL but also for developing mag-
netic fusion in general, Prager said.
A smaller device, PPPL’s Lithium
Tokamak Experiment, has been operating
with a liquid lithium surface and has had
“very favorable results,” Prager said. One
long-term goal is “to have LTX become
more integrated into the NSTX-U program,”
he said.
ROLE IN ITER
The next step in developing magnetic
fusion as a clean, abundant and safe energy
source is the international fusion experi-
ment ITER in Cadarache, France. PPPL is
strongly contributing to ITER, Prager said.
The Laboratory is designing diagnostic
port plugs for the ITER tokamak and is
responsible for purchasing and delivering
75 percent of the facility’s steady-state elec-
tric network, which will provide power for
all steady state electrical uses at the ITER
site. In addition, research conducted on the
National Spherical Torus Experiment
Upgrade, PPPL’s major fusion experiment,
will produce valuable findings for ITER.
Prager noted that Richard Hawryluk
returned to PPPL after working on ITER for
two years as Deputy Director General for
the Administration Department. Hawryluk
received a certificate of appreciation from
U.S. Secretary of Energy Ernest Moniz.
Researchers are looking ahead, Prager
said, to a fusion nuclear science facility that
could eventually lead to a demonstration
plant. PPPL’ers are involved in preliminary
research investigating that possibility,
Prager said.
The Laboratory’s theory and computa-
tion research is also essential to the
Laboratory, Prager said. Last year, PPPL
researchers were awarded 270 million
hours on supercomputers to study the plas-
ma edge, the equivalent of more than
20,000 years of computer time, Prager said.
BUDGET UPS AND DOWNS
The national budget for fusion energy
research has been a “roller coaster ride for
the research program,” Prager said. After
dipping from 2012 to 2013 it was back up to
$306 million for research in fiscal year 2014
and increased again in 2015 to 317.5 mil-
lion. At the same time, the ITER construc-
tion budget decreased to $150 million from
$200 million the previous year.
PPPL’s funding from DOE’s Office of
Fusion Energy Sciences (OFES) also
dipped from 2012 to 2013. The FY 2014 esti-
mated budget for PPPL totals $96 million,
including $80 million from OFES. PPPL’s
final budget for fiscal year 2015 has not yet
been decided. .
The good news is that the 2015 budget
includes an additional $25 million for infra-
structure improvements, as part of an over-
all campus plan. “This is fantastic,” Prager
said. The plan would consolidate all of
PPPL shops into one building. It would also
update PPPL’s laboratories, particularly for
smaller experiments; modernize office
spaces, and upgrade the Lab’s electrical
and mechanical infrastructure.
OTHER NEW EXPERIMENTS &
COLLABORATIONS
In addition to PPPL’s main experiment,
the Laboratory has also moved ahead with
several new experiments and collabora-
tions, Prager said. One such facility is a
new version of the Magnetic Reconnection
Experiment called FLARE to study magnet-
ic disturbances that cause northern lights
solar flares, geomagnetic disturbances, and
numerous astronomical phenomena.
FLARE will be three times bigger and
much more powerful than the current
STEWART PRAGER
Director
Princeton Plasma Physics Lab (PPPL)
(continued page 27)