Priorities in Fusion Data Compilation

The long-term priorities in A+M and PMI data needs for fusion energy research are regularly reviewed during the IAEA Data Centre Network (DCN) Meeting on "Technical Aspects of A+M Data Processing and Exchange". With regard to data production, both large scale advanced calculations as well as benchmark experiments for validation are needed. The DCN also supports the development of XSAMS (XML Schema for Atoms, Molecules and Solids), a new standard for AM/PMI data exchange, as reliable and convenient tools for data exchange are essential with the development of Internet Technologies. The last DCN meeting was held in September 7-9, 2009 in the IAEA Headquarters in Vienna.

Atomic and Molecular Data

Spectroscopic Data

Collisional Data for Plasma Edge Studies

This section includes neutral particle transport modeling and diagnostics, H-recycling and He-exhaust. All the molecular data are needed for different hydrogen isotopes, including mixed molecules like DT.

Despite considerable progress made in CRP work, there continues to be a need for data production and evaluation for collisional data for hydrocarbons and other molecules relevant to fusion devices:

Regarding collision processes of high-Z impurities, the CRP on "Atomic Data for Heavy Element Impurities in Fusion Reactors" is addressing some of these issues, concentrating on W and the noble gases. A CRP on tungsten will be initiated in 2010.

From previous data priority lists, the following data needs have been addressed. Existing databases appear to be sufficient at this time and no new requests have been made recently:

Collisional Data for neutral particle beam heating

Radiative Plasma Cooling

These data are important for determination of ionization balance and radiation losses. It would be very useful to formulate updated and new tables of cooling rates.

Core plasma

Electron impact processes (excitation, ionization, radiative and dielectronic recombination) of medium- and high-Z impurities (W, Ar, Ne, Kr, Xe are highest priority, with V, Ti, Cr, Fe, Ni, Mo of lower priority). Pertinent temperature range is from ~1 keV to ~30 keV. A large amount of data exists for Ti and Fe, but dielectronic recombination rate coefficients are not adequate for L-shell and M-shell ions even for Fe. The CRP on "Atomic Data for Heavy Element Impurities in Fusion Reactors" addressed some of these issues.

Edge plasma

Data are needed for edge temperature (threshold to ~500eV) charge exchange processes among intrinsic impurities and plasma components:

Plasma-Material Interaction

Erosion

Hydrogen isotope reflection, retention and release in fusion materials and codeposited layers

Molecular balance on surfaces

There is a strong need of data in this area, emphasizing inclusion of molecular vibration:

  • Molecule and molecular ion formation and destruction with identification of product charge and quantum state.
  • Data for hydrocarbons and H- formation on surfaces, particle sticking, pumping, gettering, and recycling.

    Material Properties

    Data collection and generation are needed:

  • Data on size distribution, composition, formation etc for erosion products (dust, flakes etc) containing C, Be, W. A CRP was initiated in 2008 on dust formation and characterization.
  • Tritium retention in erosion products.
  • Chemical properties of erosion products.
  • Mobilization of particles. Good diagnostics will be important.
  • Neutron induced damage, gas bubble formation in wall material from protons and alpha particles formed by neutron reactions and directly from fusion plasma implantation.