Atomic and Molecular Databases and Data Evaluation Activities at the National Institute for Fusion Science

We have constructed and opened atomic and molecular (AM) numerical databases for collision processes important for fusion research. Our databases are accessible through the Internet; the data are retrievable and are displayed as a table or a graph. The databases have been used for data evaluation. Critical assessments of AM data have been carried out since 1978 for electron impact ionization and excitation cross sections, rate coefficients, and charge-transfer cross sections of atom-ion collisions, for helium, carbon, oxygen, etc. Evaluated data are fitted to analytic formulas that have physically correct asymptotic behavior. As another type of evaluation, recommended data sets were selected for electron impact excitation rate coefficients of Fe atoms and ions. Because a large amount of data exists, recommended data are not fitted to analytic formulas, but all data are available as electronic files via the Internet. In addition to AM data, physical sputtering yields and backscattering coefficients are also stored as databases, and empirical formulas have been obtained since the 1980s. All evaluated data are published as research reports of the Institute for Plasma Physics of Nagoya University and the National Institute for Fusion Science of Japan. It is important to establish a systematic way for data evaluation by international collaborations to develop an evaluated AM database required for fusion research.