vi
Preface
Thus, PMI is a critical scientific issue for the establishment of a fusion reactor as
a power source, with major potential limitations on plasma core and edge operating
parameters. Gaining understanding and predictive capability in this area will require
simultaneously addressing complex and diverse physics and chemistry occurring
over a wide range of lengths (angstroms to meters) and times (femtoseconds to days).
Furthermore, the following key engineering issues remain: lifetime of plasma-facing
components (PFC’s) due to steady-state sputter erosion; erosion/damage by plasma
transients; surface ultrastructure and mixed-material evolution; plasma contamination by eroded material and plasma operating limits due to these factors. Shortage of
tritium fuel resources and radioactivity give additional issues for fuel self-sufficiency
and nuclear safety in controlling PMI.
Although many books and reviews have already been published on PMI some of
which are referred in Chap. 1, they are mostly standing on plasma physics, namely
how plasma or plasma confinement is influenced by PMI. This book stands on the
material side focusing on changes caused by heat and particle load, i.e. how plasmafacing materials (PFM) are modified by plasma exposure and then accordingly how
the modified PFM responds to the plasmas.
After the introduction of PMI in Chap. 1, Chap. 2 describes what present tokamak
discharges look like and Chap. 3 describes the power load on PFM. Then basic
processes of PMI are described in Chaps. 4–7: “Responses of plasma-facing surfaces
to heat and particle loads” in Chap. 4, “Erosion and deposition and their influence
on plasma behavior” in Chap. 5, “Material modification by high-power load and
its influence on plasma” in Chap. 6, and “Fundamentals of hydrogen recycling and
retention” in Chap. 7. In Chap. 8, “PMI in large Tokamaks” is discussed and in
Chap. 9, “Estimation of tritium retention in a reactor” is discussed.
In Chap. 10, “Selection of PFM” is discussed. Finally in Chap. 11, “Closing
remarks, including future prospect” is given.
Hopefully, this book will help in the understanding of PMI and its impact on
plasma confinement and will preview what kind of research and development will
be required.
Osaka, Japan
Tetsuo Tanabe
Preface
Thus, PMI is a critical scientific issue for the establishment of a fusion reactor as
a power source, with major potential limitations on plasma core and edge operating
parameters. Gaining understanding and predictive capability in this area will require
simultaneously addressing complex and diverse physics and chemistry occurring
over a wide range of lengths (angstroms to meters) and times (femtoseconds to days).
Furthermore, the following key engineering issues remain: lifetime of plasma-facing
components (PFC’s) due to steady-state sputter erosion; erosion/damage by plasma
transients; surface ultrastructure and mixed-material evolution; plasma contamination by eroded material and plasma operating limits due to these factors. Shortage of
tritium fuel resources and radioactivity give additional issues for fuel self-sufficiency
and nuclear safety in controlling PMI.
Although many books and reviews have already been published on PMI some of
which are referred in Chap. 1, they are mostly standing on plasma physics, namely
how plasma or plasma confinement is influenced by PMI. This book stands on the
material side focusing on changes caused by heat and particle load, i.e. how plasmafacing materials (PFM) are modified by plasma exposure and then accordingly how
the modified PFM responds to the plasmas.
After the introduction of PMI in Chap. 1, Chap. 2 describes what present tokamak
discharges look like and Chap. 3 describes the power load on PFM. Then basic
processes of PMI are described in Chaps. 4–7: “Responses of plasma-facing surfaces
to heat and particle loads” in Chap. 4, “Erosion and deposition and their influence
on plasma behavior” in Chap. 5, “Material modification by high-power load and
its influence on plasma” in Chap. 6, and “Fundamentals of hydrogen recycling and
retention” in Chap. 7. In Chap. 8, “PMI in large Tokamaks” is discussed and in
Chap. 9, “Estimation of tritium retention in a reactor” is discussed.
In Chap. 10, “Selection of PFM” is discussed. Finally in Chap. 11, “Closing
remarks, including future prospect” is given.
Hopefully, this book will help in the understanding of PMI and its impact on
plasma confinement and will preview what kind of research and development will
be required.
Osaka, Japan
Tetsuo Tanabe