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

Self-organized striated structures of the plasma emission have recently beenobserved in capacitive radio-frequency CF4 plasmas by Phase Resolved OpticalEmission Spectroscopy (PROES) and their formation was analyzed and understoodby Particle in Cell / Monte Carlo Collision (PIC/MCC) simulations [Y.-X. Liu,et al. Phys. Rev. Lett. 116, 255002 (2016)]. The striations were found toresult from the periodic generation of double layers due to the modulation ofthe densities of positive and negative ions responding to the externallyapplied RF potential. In this work, an in-depth analysis of the formation ofstriations is given, as well as the effect of the driving frequency on theplasma parameters, such as the spatially modulated charged species densities,the electric field, and the electron power absorption is studied by PROESmeasurements, PIC/MCC simulations, and an ion-ion plasma model. The measuredspatio-temporal electronic excitation patterns at different driving frequenciesshow a high degree of consistency with the simulation results. The striationgap (i.e., the distance between two ion density maxima) is found to beinversely proportional to the driving frequency. In the presence of striationsthe minimum(CF_3^+, F^-) ion densities in the bulk region exhibit anapproximately quadratic increase with the driving frequency. For thesedensities, the eigenfrequency of the ion-ion plasma is near the drivingfrequency, indicating that a resonance occurs between the positive and negativeions and the oscillating electric field inside the plasma bulk. The maximum iondensities in the plasma bulk are found not to exhibit a simple dependence onthe driving frequency, since these ion densities are abnormally enhanced withina certain frequency range due to the ions being focused into the "striations"by the spatially modulated electric field inside the bulk region.

plasma sources science and technology

Striations in electronegative capacitively coupled radio-frequency  plasmas: analysis of the pattern formation and the effect of the driving  frequency