The torus volume axis field doesn’t guide the motion of the particles as expected because the initial emission velocity of the particles dominates the motion of the particles rather than the field. You can use a particle object’s Conserve attribute to scale down the emission velocity’s influence and increase the field’s influence.

To adjust the velocity of moving particles

1. Select the particle object and set the Conserve attribute to 0.8 in the Channel Box.

   By changing the Conserve value from the default value, 1, to 0.8, the emission velocity’s influence on the particle motion decreases and the field’s influence increases.

2. Go to the start of the playback range and play the animation. Notice how the particle movement now conforms to the shape of the torus volume field.