>>12579070
An intuitive way of understanding why this happens is to imagine a cyclotron moving linearly along its rotation symmetry axis, while also spinning a particle in a closed circle.
As the particle’s speed increases, the magnitude of its momentum vector may increase without bound, however, the magnitude of the velocity vector may not. Spinning the particle causes the momentum components in the rotation plane to dominate the linear axis component, so the momentum vector converges into the rotation plane. At the same time, the velocity vector must point in the same direction as the momentum vector, so it will also converge towards the rotation plane, but because the speed of the particle has a finite bound, the particle must lose some of its linear axis velocity component to gain some rotation plane velocity components.