Light Element Atom, Molecule and Radical Behaviour in the Divertor and Edge Plasma Regions

Light elements are the dominant impurity species in fusion research devices. Although a large amount of data exist for a number of processes in several ion stages of elements of interest, significant gaps remain. The CRP will generate new data on processes including excitation, ionization, recombination and heavy particle collisions for ions of hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen and oxygen and molecules of these atoms. Hydrogen isotopes constitute the fuel of fusion reactors, helium is the product of the fusion reaction, lithium is used as a beam diagnostic material, beryllium is a wall material of fusion vessels, boron is used as a coating material in fusion vessels, carbon is used in several fusion divertor plates and nitrogen is under investigation as a buffer gas in fusion devices. Data for many of these processes are either poorly known or non-existent. The proposed CRP will produce an electronically accessible assessed database for light element impurities in fusion devices and the publication of results in scientific journals, thus contributing to the development of controlled fusion devices.