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

There have been discussions in the recent literature regarding the accuracyof the available electron impact excitation rates (equivalently effectivecollision strengths $\Upsilon$) for transitions in Be-like ions. In the presentpaper we demonstrate, once again, that earlier results for $\Upsilon$ areindeed overestimated (by up to four orders of magnitude), for over 40\% oftransitions and over a wide range of temperatures. To do this we have performedtwo sets of calculations for N~IV, with two different model sizes consisting of166 and 238 fine-structure energy levels. As in our previous work, for thedetermination of atomic structure the GRASP (General-purpose RelativisticAtomic Structure Package) is adopted and for the scattering calculations (thestandard and parallelised versions of) the Dirac Atomic R-matrix Code ({\scdarc}) are employed. Calculations for collision strengths and effectivecollision strengths have been performed over a wide range of energy (up to45~Ryd) and temperature (up to 2.0$\times$10$^6$~K), useful for applications ina variety of plasmas. Corresponding results for energy levels, lifetimes andA-values for all E1, E2, M1 and M2 transitions among 238 levels of N~IV arealso reported.

Electron impact excitation of N IV: calculations with the DARC code and a comparison with ICFT results