beam thermal velocity

例句：

1. 1.The beam thermal velocity of the laser is very high.
   激光的光束热速度非常高。
2. 2.The beam thermal velocity of light is constant.
   光的光束热速度是恒定的。
3. 3.The beam thermal velocity of a particle beam is determined by its energy and mass.
   粒子束的光束热速度由其能量和质量决定。