Theoretical investigation of spectroscopic properties of W25+

- Energy levels and radiative transition probabilities are studied for the W25+ ion.
- Correlation effects are investigated for main configurations of the ion.
- The corona model is used to find lines in spectra.

Energy levels and emission spectra of W25+ ion have been studied by performing the large-scale relativistic configuration interaction calculations. Configuration interaction strength is used to determine the configurations exhibiting the largest influence on the 4f3, 4d94f4, 4f25s, 4f25p, 4f25d, 4f25f, 4f25g, and 4f26g configuration energies. It is shown that correlation effects are crucial for 4f25s→4f3 transition which in a single-configuration approach occurs due to the weak electric octupole transitions. As well, the correlation effects affect 4f25d→4f3 transitions by increasing transition probabilities by an order. The corona model has been used to estimate the contribution of various transitions to the emission in a low-density electron beam ion trap (EBIT) plasma. Modeling in 10-30 nm wavelength range produces lines which do not form emission bands and can be observed in EBIT plasma.