Parametric decay instability of circularly polarized Alfvén wave in magnetically dominated plasma
Fuente:
arXiv
Salvato in:
| Autori principali: | , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2024
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866913393880858624 |
|---|---|
| author | Ishizaki, Wataru Ioka, Kunihito |
| author_facet | Ishizaki, Wataru Ioka, Kunihito |
| contents | We investigate parametric decay instability (PDI) of circularly polarized Alfvén wave into daughter acoustic wave and backward Alfvén wave in magnetically-dominated plasma, in which the magnetization parameter $σ$ (energy density ratio of background magnetic field to matter) exceeds unity. We analyze relativistic magnetohydrodynamics (MHD), focusing on wave frequencies sufficiently lower than the plasma and cyclotron frequencies. We derive analytical formulae for the dispersion relation and growth rate of the instability as a function of the magnetization $σ$, wave amplitude $η$, and plasma temperature $θ$. We find that PDI persists even in high magnetization $σ$, albeit with a decreased growth rate up to $σ\to\infty$. Our formulae are useful for estimating the decay of Alfvén wave into acoustic wave and heat in high magnetization $σ$ plasma, which is a ubiquitous phenomenon such as in pulsars, magnetars, and fast radio bursts. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2404_15689 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Parametric decay instability of circularly polarized Alfvén wave in magnetically dominated plasma Ishizaki, Wataru Ioka, Kunihito High Energy Astrophysical Phenomena Optics Plasma Physics We investigate parametric decay instability (PDI) of circularly polarized Alfvén wave into daughter acoustic wave and backward Alfvén wave in magnetically-dominated plasma, in which the magnetization parameter $σ$ (energy density ratio of background magnetic field to matter) exceeds unity. We analyze relativistic magnetohydrodynamics (MHD), focusing on wave frequencies sufficiently lower than the plasma and cyclotron frequencies. We derive analytical formulae for the dispersion relation and growth rate of the instability as a function of the magnetization $σ$, wave amplitude $η$, and plasma temperature $θ$. We find that PDI persists even in high magnetization $σ$, albeit with a decreased growth rate up to $σ\to\infty$. Our formulae are useful for estimating the decay of Alfvén wave into acoustic wave and heat in high magnetization $σ$ plasma, which is a ubiquitous phenomenon such as in pulsars, magnetars, and fast radio bursts. |
| title | Parametric decay instability of circularly polarized Alfvén wave in magnetically dominated plasma |
| topic | High Energy Astrophysical Phenomena Optics Plasma Physics |
| url | https://arxiv.org/abs/2404.15689 |