DIAGNOSTICS OF THE ANISOTROPY OF THE ELECTRON-DISTRIBUTION FROM THE ANALYSIS OF X-RAY-LINE POLARIZATION

X-ray lines are emitted by very hot plasmas such as fusion plasmas (ma gnetic or inertial confinement) and astrophysical plasmas (solar and s tellar flares, galaxies, etc.). The excitation processes of the atomic levels are often anisotropic and the emission lines can be expected t o be polarized. The measurements of line polarization could give valua ble information on the electron energy and angular distribution. The a tomic data required to calculate the polarization being very sensitive to the quality of the theoretical method used, it is important to be able to check their accuracy by comparison with experiments. Recently the development of EBIT sources has allowed it to be done. In these de vices, the ions being excited by an electron beam, the X-ray emission is often polarized.