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

to stabilize deleterious plasma modes and improve plasma performance. The key to this ability is
an improved final steering mirror exposed to the plasma. iteR is supporting the development of
several new diagnostics that are able to operate in the neutron environment in iteR. While the
developments needed for iteR have driven necessary research, there is still a big gap to a demo
device.
While the progress in taming plasma-material interactions is notable, there is still a large gap to
close before we are ready to undertake a demo. Greater emphasis needs to be placed on edge plasma
diagnostics and development of physics models of the edge on existing machines. to meet the
expected conditions in future fusion machines, existing laboratory devices for basic plasma-material
interaction studies need to be upgraded and new facilities built. innovative solutions that can increase
the capability and robustness of plasma facing components require a new investment of funds
and people. These changes should be coordinated on a national level. Without these changes, the Us
Fusion energy sciences Program will not have the knowledge or skills to advance to the next generation
of fusion machines, let alone be ready to participate in demo. as illustrated below, several research
thrusts must cooperate in parallel to build the foundation for an integrated experiment leading
to a demo-type device.
Research Requirements
The taming the Plasma-material interface participants have identified the following key requirements
and high-leverage candidate investments.
plaSMa-Wall iNtERactioNS
Plasma-wall interactions (PWi) encompass scientific issues that are among the most critical for
fusion power, affecting: 1) lifetime of PFcs, owing to sputtering and transient erosion, 2) Plasma
contamination by eroded material, 3) tritium co-deposition in eroded and redeposited material,
and 4) operating limits on core plasma (beta, confinement, edge temperature and density, duty
factor, etc.). central to these issues is the science of plasma-material interactions (Pmi). as summarized
in the white papers, there are major gaps in modeling, analysis, and understanding Pmi
phenomena in existing machines, iteR, and certainly post-iteR devices.
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