Construction of atomic and molecular databases

Both studies of theories and experiments are explained for the construction of atomic and molecular databases. Two experimental methods, a crossed beam method and a swarm method, relating to measurements of electron collision cross sections follow the theoretical calculation of the cross sections. The crossed beam method is applied to incident electron beams with high collision energies above several eV and low densities of target atoms or molecules. The swarm method, on the contrary, is known for low collision energies below several eV. An electron beam ion trap (EBIT) is used for producing atomic data for electron-ion collision processes. It can produce highly charged ions of any element with any charge state. X-ray spectra from highly charged tungsten ions are observed in the interaction with an electron beam by EBIT. Structures of the spectra observed are concluded to be due to resonant x-ray transitions caused by dielectronic recombination processes. The EBIT exclusively enable us to measure the ionization cross sections of highly charged heavy ions in the electron impact ionization process. The cross sections for heavy ion collision processes are explained in detail from both sides of theoretical calculations and experimental measurements. Finally, some notable points for the evaluation of data are taken up to wave length, transition probabilities and collision cross sections. (Y. Kazumata)