Abstract
The present work is one of the series of investigation
on fusion reactor material erosion and redeposition processes.
Here,
the results were presented
which were obtained through optical emission spectroscopic
diagnostic analyses of molecules
resulting from hydrogenic eroded species generated
in our divertor simulation facility.
We measured rotational and vibrational excitation temperature
of the carbon-containing molecules (CH and C2) and
H2 in the laboratory plasma using optical spectroscopy.
For CH excitation temperatures,
the rotational temperatures were derived
from the vibrational temperatures.
When approaching the target,
both temperatures became almost equal.
This means that thermal equilibrium may be reached in this region
of the plasma.
For C2 excitation temperatures,
the rotational and vibrational temperatures were almost equal
at every axial point.
This result means that both species are driven
by different thermal equilibrium mechanisms.
However,
the temperatures of both species are of the same order,
indicating that the chemically eroded species are thermalized
in the plasma gas particles.
Such temperature of carbon-containing molecules will be employed
as parameters when the behaviors of chemical sputtering and
redeposition in a divertor plasma are to be numerically modeled.
Finally, it is suggested that such molecule temperatures
in some Tokamak facilities should be measured
as a means of evaluating characteristics of chemically sputtered
particles.