摘要
The electron-ion beam instability is studied by one-dimensiong electrostatic particle-in-cell simulation. When the relative drift velocity between the electron and ion is suf- ficiently less than the electron thermal speed, the dominant mode is the Langmuir wave; the ion-acoustic instability is very weak; the Buneman instability is not excited. When the relative drift speed is equal to the electron thermal speed, the Langmuir wave, the ion-acoustic and the Buneman instability nearly exist simultaneously. The three instabilities now appear to have al- most equal intensities. When the relative drift speed exceeds the electron thermal speed, the ion-acoustic instability turns into the Buneman instability which appears to have much higher intensity than the Langmuir wave.
The electron-ion beam instability is studied by one-dimensiong electrostatic particle-in-cell simulation. When the relative drift velocity between the electron and ion is suf- ficiently less than the electron thermal speed, the dominant mode is the Langmuir wave; the ion-acoustic instability is very weak; the Buneman instability is not excited. When the relative drift speed is equal to the electron thermal speed, the Langmuir wave, the ion-acoustic and the Buneman instability nearly exist simultaneously. The three instabilities now appear to have al- most equal intensities. When the relative drift speed exceeds the electron thermal speed, the ion-acoustic instability turns into the Buneman instability which appears to have much higher intensity than the Langmuir wave.
基金
supported by National Natural Science Foundation of China (No. 40974097)
Key Laboratory of Geospace Environment,University of Science & Technology of China, Chinese Academy of Sciences
