Research Needs for Magnetic Fusion Energy Sciences - US Burning ...

for use by researchers beyond the developers. teams, providing “production” quality tools, need
resources for end-user support and training.
The fusion community needs more analysts, as defined earlier, with broad knowledge of theory,
codes, experiments and statistical techniques for estimating uncertainties and errors. computer
time required for verification and validation will rival that used by the developers. and while
there is a need for both capability and capacity computing, this Thrust will not be accomplished
through a few heroic calculations, but by thousands of large runs, investigating parameter dependence
and testing equations one term at a time.
improved measurements are the key to validating the models and will require substantial investment
in diagnostics. We will need to measure quantities that are currently inaccessible and improve
the spatial coverage for those already measured. new experiments will likely be required
— particularly small-scale laboratory devices that can test the most basic elements of complex
nonlinear models. advanced diagnostics will be required on these experiments, perhaps supplied
through multi-institutional collaborations as they often are on larger facilities. The largest facilities
will also require improved diagnostic sets and must have adequate run time to support the
added demands of a more comprehensive validation program. international collaborations on experiments
or diagnostics should be actively sought where appropriate.
Work on this Thrust could begin now. all of the elements described can be addressed, at some level,
without waiting for future results or facilities. The FsP, which could form part of this Thrust,
is already in a program definition phase. other theory and computation activities could be augmented
to fill in gaps as they are identified. Requirements for new diagnostics or new experiments
could be assessed and design work begun. at the same time, this Thrust will benefit from
future developments. new machines, such as the asian superconductive tokamaks and those proposed
in other ReneW thrusts, and in particular iteR, provide platforms for model testing that
extend beyond the parameter ranges accessible in current machines. alternate concept devices
would likewise extend the range for validation through tests on machines with different magnetic
geometries or parameter ordering.
integration of Thrust Elements
The elements of the Thrust combine into a unified effort, integrating resources across the fusion
sciences program. Theory, computation and experiments are coordinated to solve a set of the most
critical plasma physics problems. topical science areas would be integrated at appropriate levels,
spanning a wide range in temporal and spatial scales and physical phenomena. a broad spectrum
of codes would be developed or exploited, ranging from single-developer research codes to large
collaborative efforts, such as those produced by the FsP. The Thrust would benefit from close collaboration
among applied mathematicians, computer scientists and plasma physicists. it would
utilize the full spectrum of experimental facilities and require the application of new ideas and
advanced technologies to produce innovative diagnostics crucial for code validation. The impact
of the Thrust would be felt across the entire program, motivating and guiding theory and computation
through closer interaction with experiments. it would provide stronger motivation for diagnostic
development and place demands for run time on experimental facilities. Progress would
enable more complex experiments to be performed with the help of accurate scenario modeling
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