It is suggested that the instability is excited in the low density plasma when the electron beam drift velocities exceed the ion acousticspeed.
不稳定性产生的可能机制是由于电子束穿过低密度本底等离子体的漂移速度超过离子声速而激发起来的。
2
The principle and method of measuring the acousticspeed CVD diamond film with piezoelectric film detecting laser ultrasonic system are presented.
本文介绍了压电薄膜检测的激光超声系统对CVD金刚石膜声速测量的原理及方法。
3
Methods The color and transparency of different concentration phantoms were observed. Properties including density, acousticspeed and acoustic attenuation of PAA gel phantom were measured.