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

3) as planning matures for the research program, new measurement needs are sure to arise,
and “emerging gaps” will be identified. an example might be an added measurement needed
for a promising control scenario successfully developed on an operating device.
4) to avoid difficult maintenance and repair procedures involving remote robotic handling,
failure rates much lower than on present-day devices must be achieved. This represents
a significant engineering and technological challenge affecting a variety of diagnostic
components, including maintenance, alignment, and calibration subsystems.
5) it is highly likely that some techniques yielding crucial measurements will not work in a
demo environment, e.g., proximity-coil-based magnetic measurements and optical-based
measurements. Thus, new techniques are needed for these measurements at risk in demo.
in particular, novel and robust plasma-diagnostic interfaces should be developed.
as a high-priority Us diagnostic activity, the Us iteR Project office is delivering a specific subset
of diagnostics to the iteR organization. Us developers will have to demonstrate, through qualification
testing, that this hardware will operate reliably in an iteR environment. Thus, some of
the issues mentioned earlier will be addressed for these specific diagnostics. however, the UsiPo
responsibility does not extend to issues 1), 3), and 5). nor is it likely to be able to fully address generic
aspects of 2) or 4), such as first-mirror lifetime prediction and validation. Us expertise could
help address at least some of these areas not included in the UsiPo scope. Unfortunately, as presently
structured, no Us program exists to fund such efforts.
major Us experimental fusion programs have benefited greatly from office of Fusion energy sciences
(oFes) awards for “development of diagnostic systems for magnetic Fusion energy sciences
experiments.” however, this program supports developments benefiting research on existing
facilities only. major Us fusion programs also support valuable diagnostic developments in support
of associated research. in both cases, developments may be applicable to burning plasmas.
however, the considerable effort required to translate these developments into conceptual iteRrelevant
or demo-relevant designs and to evaluate expected performance at burning plasma parameters
presently has no funding path available.
a broader mandate is needed for Us experts to consider a full range of measurement issues. For example,
robust, burning-plasma-relevant alternatives for techniques that work well on existing devices
must be developed. Generic efforts to reduce risk and enhance reliability in a burning plasma
environment are needed. a targeted solicitation based on prioritized issues could be used to launch
a program to develop burning plasma diagnostics outside of the scope of the UsiPo, in coordination
with efforts worldwide. dividends from this new investment would be a more vigorous research program
on iteR and a firmer basis for the design of measurements for next-step steady-state devices.
iteR provides a near-term focus for this Thrust. implementation of diagnostics on demo is longer
term, but also a very critical issue. in most cases for demo, measurement concepts do not exist.
Fundamental materials issues will confront designers of sensors in proximity to the plasma.
all techniques will need to adapt to greatly reduced access through which to collect signals. The
envisioned effort, to develop reliable techniques compatible with the more hostile steady-state
demo environment, demands that this development should also begin immediately.
238