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

quires assessment of when potentially dangerous conditions (pressure, gradients, position, etc.)
are occurring and the implementation of prevention methods (e.g., reduced power input, plasma
movement). diagnostic systems will need to detect when dangerous conditions are present or being
approached, and intelligent analysis algorithms will need to make real-time decisions. The detection/decision
process must occur on the time scale of milliseconds to actuate a prevention and/
or mitigation strategy. This must be done with high reliability, since the safe operation and integrity
of the device may be at risk from the off-normal event. development and testing of such systems
is crucial to the success of burning plasma systems.
Develop methods of Integrated Data Analysis and continue implementation of synthetic diagnostics
in relevant codes
optimizing the interpretation and analysis of measurements aids in more complete exploitation
of data for understanding and predicting burning plasmas. We identify two areas where continued
development is needed and will provide enhanced measurement capability. in particular,
methods of “integrated data analysis” are required to combine related measurements from complementary
diagnostics to minimize errors, resolve data inconsistencies, and obtain a validated
data set. 4 because the implementation of “synthetic diagnostics” (i.e., predicting the quantity that
a diagnostic actually measures) in modeling codes has been shown to be useful, more accurate diagnostic
modeling within our available relevant codes is highly desired.
COnCLuSiOn
time Scales for Research
We have deliberately not called for research on specific measurement techniques and diagnostics,
since in many cases we cannot at present define the specific techniques that will be used or desired
– indeed the creation of capable and compatible techniques is a major goal of the research.
as the research program defines the desired measurement capabilities and thereafter, it must assess
the existing capability of making each measurement and facilitate the research and development
still needed. This will certainly require responsive support for short- and long-term development
and implementation of new diagnostics and diagnostic techniques. measurement capability
for both burning and non-burning plasmas must be systematically developed. new diagnostic
techniques can take ~10 years to mature. They must move from prototypes, to validation, and to
reliability demonstrations on nonburning plasmas. additionally, they must be modeled and/or
tested (if possible) in a nuclear environment before they are commissioned on a burning plasma
device.
Research benefits
The quality and coverage of measurements directly affect essentially all aspects of experimental
burning plasma science. This research will enable both predictive capability applied to burning
plasmas, as well as increase the quality and number of the measurements used for burning plasma
diagnosis and control.
4 See, for example, R. Fischer et al., Plasma Phys. Control. Fusion 45 (2003) 1095–111.
64