3 years ago

Local Gyrokinetic Study of Electrostatic Microinstabilities in Dipole Plasmas.

Wei-ke Ou, Bo Li, Yi Zhang, Hua-sheng Xie, Zi-cong Huang

A linear gyrokinetic particle-in-cell scheme, which is valid for arbitrary perpendicular wavelength $k_\perp\rho_i$ and includes the parallel dynamic along the field line, is developed to study the local electrostatic drift modes in point and ring dipole plasmas. We find the most unstable mode in this system can be either electron mode or ion mode. The properties and relations of these modes are studied in detail as a function of $k_\perp\rho_i$, the density gradient $\kappa_n$, the temperature gradient $\kappa_T$, electron to ion temperature ratio $\tau=T_e/T_i$, and mass ratio $m_i/m_e$. For conventional weak gradient parameters, the mode is on ground state (with eigenstate number $l=0$) and especially $k_\parallel\sim0$ for small $k_\perp\rho_i$. Thus, bounce averaged dispersion relation is also derived for comparison. For strong gradient and large $k_\perp\rho_i$, most interestingly, higher order eigenstate modes with even (e.g., $l=2,4$) or odd (e.g., $l=1$) parity can be most unstable, which is not expected by previous studies. High order eigenstate can also easily be most unstable at weak gradient when $\tau>10$. This work can be particularly important to understand the turbulent transport in laboratory and space magnetosphere.

Publisher URL: http://arxiv.org/abs/1710.11384

DOI: arXiv:1710.11384v1

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.