نوع مقاله : مقاله پژوهشی

نویسنده

گروه فیزیک، دانشکده علوم پایه، دانشگاه گنبد کاووس، صندوق پستی: 163، گنبد کاووس - ایران

چکیده

در این مقاله انتشار امواج غیرخطی یون- صوتی در یک پلاسمای برخوردی با حضور الکترون­های فوق­حرارتی با تابع توزیع کاپا مطالعه شده است. با نوشتن معادلات سیالی برای یون­ها و لحاظ کردن سهم برخورد بین یون­ها با اتم­های خنثی و هم­چنین به­کار بردن روش اختلال کاهشی، معادله غیرخطی تعمیم­یافته کورته وگ- ده وری (K-dV) تعیین شده است. نتایج نشان­دهنده انتشار پالس الکتریکی با دامنه مثبت (امواج سالیتونی متراکم) است. بررسی‌های عددی نشان می‌دهند که برخورد یون­ها با اتم­های خنثی تأثیر ویژه‌ای بر ساختار امواج یون- صوتی دارند. به­عبارت دیگر، با افزایش فرکانس برخورد دامنه (پهنای) موج یون- صوتی کاهش (افزایش) می‌یابد. علاوه براین، اثر شاخص طیفی الکترون­های فوق­حرارتی و دمای یون­ها نیز بر ساختار این امواج مورد بررسی قرار گرفته است.

کلیدواژه‌ها

عنوان مقاله [English]

Influence of ion-neutral collisional frequency and Kappa spectral index on dynamics of nonlinear ion-acoustic waves in superthermal plasmas

نویسنده [English]

  • M. Mehdipoor

Department of Physics, Faculty of Science, Gonbad Kavous University, P.O.Box: 163, Gonbad Kavous - Iran

چکیده [English]

The present work investigates the propagation of nonlinear ion-acoustic waves in a collisional plasma with superthermal electrons and a Kappa distribution function. Considering the basic fluid equations and the ion-neutral collisions, a modified nonlinear Korteweg-de Vries (K-dV) equation is derived using the reductive perturbation method. It was found that only compressive ion-acoustic solitary waves can be propagated in this model. Also, the numerical results show that ion-neutral collisions have significant effects on solitary wave structures. In other words, the amplitude (width) of the ion-acoustic solitons decreases (increases) with increasing the ion-neutral collision frequency. Moreover, the present plasma model has also studied the effects of the spectral index of superthermal electrons and ion temperature on the ion-acoustic solitons

کلیدواژه‌ها [English]

  • Ion-acoustic waves
  • Collisional plasma
  • Superthermal electrons
  • Reductive perturbation method
  • Modified K-dV equation
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