English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this work, visible and extreme ultraviolet spectra of W7+ are measuredusing the high-temperature superconducting electron-beam ion trap (EBIT) at theShanghai EBIT Laboratory under extremely low-energy conditions (lower than thenominal electron-beam energy of 130 eV). The relevant atomic structure iscalculated using the flexible atomic code package based on the relativisticconfiguration interaction method. The GRASP2K code, in the framework of themulticonfiguration Dirac-Hartree-Fock method, is employed as well forcalculating the wavelength of the M1 transition in the ground configuration ofW7+. A line from the W7+ ions is observed at a little higher electron-beamenergy than the ionization potential for W4+, making this line appear to befrom W5+. A hypothesis for the charge-state evolution of W7+ is proposed basedon our experimental and theoretical results; that is, the occurrence of W7+ions results from indirect ionization caused by stepwise excitation betweensome metastable states of lower-charge-state W ions, at the nominalelectron-beam energy of 59 eV.

Observation of indirect ionization of W7+ in an electron-beam ion-trap plasma