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

Further progress in the development of ECR ion sources (ECRIS) requiresdeeper understanding of the underlying physics. One of the topics that remainsobscure, though being crucial for the performance of the ECRIS, is the electronenergy distribution (EED). A well-developed technique of measuring the EED ofelectrons escaping axially from the magnetically confined plasma of an ECRISwas used for the study of EED in unstable mode of plasma confinement, i.e. inthe presence of kinetic instabilities. The experimental data were recorded forpulsed and CW discharges with a room-temperature 14 GHz ECRIS at the JYFLaccelerator laboratory. The measurements were focused on observing differencesbetween the EED escaping from a stable and unstable plasmas. It was found thatnonlinear phenomena alter the EED noticeably. The electron losses are enhancedin both unstable regime and with two-frequency heating suppressing theinstabilities. It has been shown earlier that two-frequency heating boosts theECRIS performance presumably owing to the suppression of instabilities. Wereport the observed changes in EED introduced by the secondary frequency indifferent regimes, including an off-resonance condition where the secondaryfrequency is lower than the minimum frequency satisfying the resonancecondition for cold electrons at the magnetic field minimum. Finally, we suggestan experimental method of qualitative evaluation of the energy distribution ofelectrons confined in the magnetic trap using a method of measuring energydistribution of lost electrons during the plasma decay in pulsed operation ofthe ion source.

Measurements of the energy distribution of electrons lost from the minimum B-field -- the effect of instabilities and two-frequency heating