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Spectroscopic observations of charge exchange recombination in tokamak plasmas during high power neutral beam heating experiments and effect of such recombination as well as transport processes on ionization equilibrium are presented. Application of charge exchange recombination for measurements of totally stripped ion densities is also discussed. Special attention is devoted to spectroscopic measurements of ion temperature and impurity concentration by using long-wavelength forbidden lines (from magnetic dipole transitions) of highly ionized atoms and K_α lines of helium- and lithium-like Fe and Ti ions in the X-ray region (crystal spectroscopy). Fluorescense spectroscopy applications for ion density measurements in the plasma periphery is also presented. All these presentations are related to requirements of accuracy and of new calculations and measurements of rate coefficients for ionization, recombination (radiative, dielectronic and charge exchange) and excitation for the CTR program.

Impurity control experiments have been summarized in DIVA and JFT-2 at JAERI. Plasma purity improved by a divertor, by a titanium (medium-Z) wall or by a carbon (low-Z) wall has remarkably favorable effects on confinement, stability and high-density operation. Highly-ionized impurity ions accelerated by a sheath potential in front of the bombarded wall play a predominate role in generation of the wall impurity. Detailed study of a scrape-off layer proposes the scaling law on the scrape-off plasma. According to the proposed scaling law, the impurity control is essential to realize successfully fusion-state tokamaks in future. Ion (including highly-charged impurity ion) sputtering, chemical sputtering (potential disadvantage of low-Z carbon materials) and impurity behavior near the wall are of great importance for the future impurity control.

This paper contains a review of experimental results from the DITE bundle divertor. The three basic properties of the divertor: particle exhaust, particle screening and energy exhaust, are considered separately. These three properties combine to improve the purity of the plasma in discharges with the divertor energised when compared with similar density discharges with no divertor. The importance of a better understanding of particle and energy transport in the outer regions of the plasma is highlighted, in order to make predictions for future tokamak divertors.

The fast neutral injection method has proved to be a very efficient heating method either in open-ended configurations, or in toroidal configurations.

Compared to other heating methods the fast neutral injection involves more technological difficulties, but less physical complexities. Furthermore these difficulties are met out of the plasma configuration and can be solved without stopping the confining machine. So it is quite natural in a paper devoted to fast neutral injection to divided it into two parts, the first part involves the production of the fast neutral beam, the second part involves the interaction of the neutrals with the plasma. But in these two parts, lots of atomic and molecular physics are needed and new phenomena can be currently discovered which will be emphasized in the second part of our paper. But we will first consider the formation of the neutral beam which involves considerations on ion sources, acceleration and neutralization systems. In the second paper we will consider more the plasma physics.

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Recent work in astrophysics and in plasma physics has yielded a wealth of important data for highly ionized atoms. The results have provided strong motivations for theoretical developments as well as for complementary laboratory experiments. Light sources such as low inductance vacuum sparks, exploding wires, laser-produced plasmas or foil-excited fast ions have been widely used in the latter case. A review is here given of some of the results obtained in recent years. Regularities of energy levels, ionization potentials and fine structure are thus summarized, the emphasis being placed on systems of relevance to the impurity problems in Tokamaks. New results for forbidden lines and studies of the structure of highly ionized, heavy atoms are also discussed. Some progress in the determination of atomic transition probabilities is briefly reported.

A critical analysis of the electron excitation cross-section and oscillator strength calculation methods has been made for fusion plasma purpose. As a practical example, a recent high spectral and time resolution tokamak spectrum is analysed. To interpret some unusual features due to the transient nature of the emitting plasma it is shown that other processes are to be included: electron excitation and ionisation of inner-shell electrons and di-electronic recombination. The atomic data calculation methods related to these further processes are therefore also reviewed.

The results of recent experimental studies of charge transfer by multiply charged ions in H and H₂ are considered in relation to current theoretical descriptions. At low velocities (V < 1 a.u.) where the collisions are quasimolecular, curve-crossings can lead to large cross-sections. For high initial charge states q, cross-sections depend on q rather than ion species. No clear relationship between cross-sections in H and those in H₂ exists. At high velocities (V > 1 a.u.) cross-sections in H and H₂ fall as V increases and scale according to qⁿ where n is between 2 and 3 for many reactions. For completely stripped ions of atomic number Z, measured cross-sections appear to scale according to Z³ at high velocities.

The available literature on electron impact ionization of ions of charge + 3 or greater is reviewed. Several easily used formulae are presented-the classical result, the Lotz formula, and a scaled Coulomb-Born prescription. The available experimental cross-sections, which now include a few good quality crossed-beams measurements, are compared with the cross-sections obtained from the formulae and, where available, with true Coulomb-Born calculations. The Lotz formula is overall found to be closest to the experimental results. However, this result is fortuitous since much of the experimental data are found to contain measurable contribution from the excitation-autoionization process not included in any of the formulae. It appears to be more important to include estimates of the excitation-autoionization contribution to ionization cross-sections than to improve the models of the direct ionization process.

A survey is presented of some achievements and problems pertaining to electron capture involving excited states in the incident or exit channel. The focus is on hydrogen. Principal experimental techniques are mentioned with their limitations. Results for the simplest processes are examined in an attempt to assess the reliability of present basic theory.

This paper considers the electronic excitation, dissociation and ionization processes for H₂, D₂, T₂, simple hydrocarbons and their ions, when bombarded by electrons. A survey is given of the different experimental cross-section results and how their consistency can be checked with analyses making use of various sum rules. Isotope effects are considered as well.

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The present status of experimental data and theoretical results on ionization and electron loss processes in collisions of hydrogenic neutrals with highly charged ions is reviewed. Special emphasis is given to the cross-section scaling laws for these processes. Further data needs, relevant to the thermonuclear fusion research, are specified.

A device has been built to measure charge changing cross-sections of atomic ions. It consists of an ECR ion source (Micromafios) that delivers oxygen ions up to charge + 8, argon ions up to charge + 13. The ion source potential may be varied from 1 up to 10 kV. A first magnet is used to charge analyze the extracted beam. For a given charge state, the ion beam is passed in a collision cell whose pressure may be varied. The ions undergoing collisions on the target are analyzed by a second magnet and collected.

The single collision condition is checked. Different collisions are considered:

(1) Charge exchange collisions of argon ions with charge 2 ⩽ Z ⩽ 12 on argon. Cross-sections for capture of 1, 2 and 3 electrons are given.

(2) Stripping of argon ions (1 ⩽ Z ⩽ 4) on argon atoms.

(3) Charge exchange of oxygen ions (2 ⩽ Z ⩽ 8) colliding on deuterium. One and two electron capture cross-sections are presented.

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The School of Physics and Mathematical Sciences at Queen's University, Belfast, is collecting atomic and molecular numerical data relevant to fusion in three different areas:

(1) Interatomic potentials and elastic collisions;

(2) Electron excitation;

(3) Assessed electron ionization and charge transfer data.

Work on the first area, Interatomic potentials and elastic collisions, was reported at the Culham Conference in 1977.

The second collection, electron excitation data, is being collected under the supervision of Dr A E Kingston and Dr K A Berrington at Queen's University with the co-operation of the Daresbury Laboratory. Much of this data is obtained directly from large computer codes.

This report is mainly concerned with the third area: the collection of assessed numerical data on atomic and molecular collisions, initially electron ionization and charge transfer.

An effort to compile atomic and molecular data has been made for several years in our Institute [1-3]. To computerize A+M data has been one of the important problems in data compilation. We have constructed a computerized data base and a retrieval-display system for the data on electron-ion collisions, as a first step. We are planning to extend it to ion-atom(ion) collisions. This system makes it possible to store and retrieve the collected data on an on-line interactive basis and to display numerical data on graphic terminal with relevant bibliographical information.

Activities on A&M data for fusion in JAERI are carried out by A&M Section in Nuclear Data Center, Division of Physics in co-operation with the Research Committee on A&M Data of JAERI which consists of the members of in- and outside of JAERI.

Since the Culham meeting in 1976, the awareness of atomic physics research needs for fusion applications and the volume of data produced for such applications has significantly increased. The present meeting fulfilled a useful function in summarizing the current fusion requirements and the status of the A+M data research work that has been performed since the Culham meeting.