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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Thermionic emission from a polycrystalline tungsten emissive cathode immersedin a magnetized plasma column is investigated experimentally and numerically.Electrical and optical measurements of the cathode temperature show a highlyinhomogeneous cathode temperature profile due to plasma-cathode interactions.The spatially and temporally resolved cathode temperature profile provides anin-depth understanding of the thermionic electron current, in excellentagreement with experimental data. The plasma-cathode coupling leads to a sharpand heterogeneous rise in temperature along the cathode, which can eventuallylead to unstable cathode operation, with divergent current growth. A detailedthermal modeling accurately reproduces the experimental measurements, andallows to quantify precisely the relative importance of heating and coolingmechanisms in the operation of the cathode immersed in the plasma. Numericalresolution of the resulting integro-differential equation highlights theessential role of heterogeneous ohmic heating and the importance of ionbombardment heating in the emergence of unstable regimes. Detailed thermalmodelling enables operating regimes to be predicted in excellent agreement withexperimental results.

Emissive cathode immersed in a plasma: plasma-cathode interactions, operation and stability