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

A new constant of motion for helically symmetric equilibria in the vicinityof the magnetic axis is obtained in the framework of Vlasov theory. In view ofthis constant of motion the Vlasov theory is compared with drift kinetic andgyrokinetic theories near axis. It turns out that as in the case ofaxisymmetric equilibria [H. Tasso and G. N. Throumoulopoulos, Phys. Plasmas 18,064507 (2011)] the Vlasov current density thereon can differ appreciably fromthe drift kinetic and gyrokinetic current densities. This indicates somelimitation on the implications of reduced kinetic theories, in particular asconcerns the physics of energetic particles in the central region ofmagnetically confined plasmas.

Vlasov versus reduced kinetic theories for helically symmetric equilibria