Kitasato University, Japan

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F. Koike
CR model
CR model of He and He-like ions is available through web page. CR model for Fe ions will come on-line soon. Ion metal surface interaction code – Hydrogen ion–metal surface interaction is also in preparation and will appear soon.

Atomic structure and dynamics calculations using the GRASP family of codes, and an introduction of some activities in NIFS [1]

Fumihiro Koike, Kitasato University and NIFS (National Institute of Fusion Science), Izumi Murakami, Daiji Kato, Xiaobin Ding, NIFS, Tohru Kawamura, TITECH

We have briefly reported on the activities in the study of atomic structure and dynamics calculations using the GRASP (General purpose Atomic Structure Program) family codes and also on some activities at NIFS. We have introduced the following items: 1. Analysis of Visible M1 Lines in Tungsten Ions, 2. Collisional-radiative model for W ions, 3. Code development for single electron capture by H nucleus from metal surface, 3. Kα radiation from low charge chlorine heated by an ion beam for plasma diagnostics, 4. Code Availability. And we have summarized the talk.

The visible light emitted from highly charged tungsten ions are of special interest; they are mainly realized by magnetic dipole transitions between the fine structure levels of ions and therefore they suffer less self-absorption by surrounding plasma providing us with a great advantage for the diagnostics of core plasma. We have studied the source of these visible line emissions in terms of accurate non-empirical atomic structure calculations and of population kinematics analyses. The GRASP package [1] for multi-configuration Dirac-Fock atomic structure calculation have provided us with the transition energies that are accurate enough to discriminate the states and the charges of tungsten ions. We tried, further, to reproduce the emission spectra by modifying a population kinetics code that has been used for the analysis of boron-like ion plasmas [2]. We have assigned new visible emission lines. We have shown that the use of the GRASP family of codes is quite effective for the spectroscopy of the visible line emissions of tungsten ions and for the diagnostics of MCF plasmas.

We have extended a CR model calculation code [2] to include the case of tungsten ions in plasma; the atomic data have been calculated using HULLAC code. We have applied the code to the analysis of W35+ to W37+ in plasma. The code is still under development. We have now under development a code for single electron capture by H nucleus from a metal surface. The features of the theoretical method implemented in the code are: 1. semi-classical treatment of H nucleus colliding with metal surface, 2. static linear density response of target electron gas induced by external nuclear charge, 3. direct numerical solution of time-dependent Schrödinger equation of electron wave-function, 4. adiabatic expansion of wave-function, and 5. B-spline method and discrete-variable-representation of the adiabatic state function. We have obtained the level populations created by electron capture from molybdenum surfaces. It is found that the code can be improved substantially (e.g. more realistic target description, beyond jellium model), and that validation of theoretical methods implemented in the code requires more comparison with experimental results. This code is, at present, not ready to be open to the public.

We have investigated the Kα radiation from low charge chlorine heated by an ion beam for ICF plasma diagnostics. In those plasmas, many Kα lines are distributed over photon energy according to the ionization state and, therefore, Kα photon energies show the characteristic charge state of plasmas. Kα with M-shell electrons may be useful for the diagnostics of lower temperature plasmas. In ions with K-shell vacancies many Auger channels compete with radiative processes and they are indispensable to estimate Kα yield.

We have discussed the availability of computer codes for open computing. We have listed out the following codes that are to be considered. 1. GRASP and GRASP2, 2. GRASP92 + RATIP,3. GRASP2K, 4. CR-Model Code based on HULLAC, 5. Code for single electron capture by H nucleus from metal surface.

[1] P. Jönsson et al., Comp. Phys. Communications, 177, 597-622 (2007)

[2] I. Murakami et al., Annual Report of NIFS, April 2005 to March 2006, 425 (2006).


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