2.3 Diagnostics for PMI Research
29
Fig. 2.11 Time evolutions
of various diagnostic data
obtained in a TEXTOR
discharge using Mo limiter;
a Mo flux and surface
temperature near the melting
surface, b Line averaged
density, c deuterium flux on
the main graphite limiter,
d total radiation, and e Mo
XXVII line intensity in the
core plasma [11]
Maker tiles consisting of different materials with layered structure are often used for
erosion measurements in ASDEX [15] and other devices.
2.4 PMI Observed by Proves and Limiter Experiments
PMI are different among materials used as PFM owing to differences in reflections of
energy and particles, erosion, and hydrogen retention properties (dissolution, trapping, diffusion and permeation). In the early days of plasma research, except the
high Z materials, like Mo and W, the effects of PFM on plasma confinement were
not concerned, but low Z impurities are ubiquitous in residual gas in a vacuum. In
recent large tokamak experiments using W as PFM, it becomes clear that plasma
behavior is significantly influenced by PMI. In references [3–15] in Chap. 1 are
described basic processes of PMI and diagnostics to observe them.
Various in situ observations of PMI have been done with using movable proves
and limiter, microbalance in addition to spectroscopic measurements. In this section,
29
Fig. 2.11 Time evolutions
of various diagnostic data
obtained in a TEXTOR
discharge using Mo limiter;
a Mo flux and surface
temperature near the melting
surface, b Line averaged
density, c deuterium flux on
the main graphite limiter,
d total radiation, and e Mo
XXVII line intensity in the
core plasma [11]
Maker tiles consisting of different materials with layered structure are often used for
erosion measurements in ASDEX [15] and other devices.
2.4 PMI Observed by Proves and Limiter Experiments
PMI are different among materials used as PFM owing to differences in reflections of
energy and particles, erosion, and hydrogen retention properties (dissolution, trapping, diffusion and permeation). In the early days of plasma research, except the
high Z materials, like Mo and W, the effects of PFM on plasma confinement were
not concerned, but low Z impurities are ubiquitous in residual gas in a vacuum. In
recent large tokamak experiments using W as PFM, it becomes clear that plasma
behavior is significantly influenced by PMI. In references [3–15] in Chap. 1 are
described basic processes of PMI and diagnostics to observe them.
Various in situ observations of PMI have been done with using movable proves
and limiter, microbalance in addition to spectroscopic measurements. In this section,