- #1
kmm
- 188
- 15
For some reason, I don't understand the direction of larmor precession. Torque is: [tex] \mathbf{\Gamma} = \frac{d \mathbf{L}}{d t} = \mathbf{r} \times \mathbf{F} [/tex] As an example, I understand with a gyroscope, using the right hand rule and with angular momentum in the direction as shown in this picture, it will precess counterclockwise looking down on it.
Now, with larmor precession, the torque is: [tex] \mathbf{\Gamma} = \frac{d \mathbf{L}}{dt} = \mathbf{\mu} \times \mathbf{B} [/tex] From the right hand rule, the torque is in the opposite direction as that of the gyroscope so the change in angular momentum should give a precession clockwise. But in the image below, and every other image I've seen, it still goes counter clockwise in the opposite direction of the change in angular momentum. Well, I have found on other sites that the change of angular momentum is in the opposite direction I get from the right hand rule. I'm not sure what I'm doing wrong. Thanks!
Now, with larmor precession, the torque is: [tex] \mathbf{\Gamma} = \frac{d \mathbf{L}}{dt} = \mathbf{\mu} \times \mathbf{B} [/tex] From the right hand rule, the torque is in the opposite direction as that of the gyroscope so the change in angular momentum should give a precession clockwise. But in the image below, and every other image I've seen, it still goes counter clockwise in the opposite direction of the change in angular momentum. Well, I have found on other sites that the change of angular momentum is in the opposite direction I get from the right hand rule. I'm not sure what I'm doing wrong. Thanks!