Quantification of chemical erosion in fusion edge plasmas is often based upon CH (Gero-band) spectroscopy. Systematic, vibrationally resolved rate coefficients for the electron impact excitation of A (2)Delta, B (2)Sigma(-) and C (2)Sigma(+) electronic states of the CH molecule are presented in the temperature range 0.2-1500 eV. The rate coefficients for 0-0 vibrational transitions are based on the R-matrix cross sections for energies below 10 eV, Born-Bethe cross sections for energies above similar to 25-30 eV and a smooth interpolation in the 10-20 eV energy range. The rate coefficients for the v-v' transitions are determined by using a scaling relationship. The implications of these results for the fusion edge/divertor plasma diagnostics, based on the A(v') -> X(v) transitions, are discussed. The rate coefficients for the 0-0 transitions are presented by convenient analytic fit expressions.
|Titolo:||Basic molecular processes for hydrocarbon spectroscopy in fusion edge plasmas: vibrationally state-selective excitation of A (2)Delta, B (2)Sigma(-) and C (2)Sigma(+) states of CH by electron impact|
|Data di pubblicazione:||2009|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1088/0741-3335/51/8/085012|
|Appare nelle tipologie:||1.1 Articolo in rivista|