Speakers
Description
Measurement of the x-ray spectra of the He-like Ni ions (Ni$^{26+}$) and their dielectronic satellites (Ni$^{25+}$, Ni$^{24+}$, and Ni$^{23+}$) plays a crucial role in determination of electronic and ionic temperature of plasma in the JET device. Because $n\ge3$ satellites of Ni$^{25+}$ overlap with resonance 'w' line of Ni$^{26+}$, it is important to reconstruct the structure of these satellites reliably. It is especially important in the cases when plasma rotation is high what results in additional shift of $n\ge3$ satellites of Ni$^{25+}$ in respect to resonance 'w' line.
Collisional-Radiative Modelling (CRM) by using the FAC code has been used for modeling the spectral emission from Ni$^{26+}$ + dielectronic satellite ions from plasmas for various electronic temperatures. Multi-Configurational Dirac-Hartree-Fock + Configuration Interaction (MCDHF-CI) calculations by using the GRASP code has been used to examining electron correlation effect on wavelengths and transition rates for $L \to K$ transitions occurs in He- and Li-like Ni ions. Basing on ab initio calculations we were searching for optimal approach to fit the $n\ge3$ satellites of Ni$^{25+}$ in experimental JET spectra.
