9. Method for detecting all vector components of a predominating spin vector in a particle beam using a spin detector arrangement for detecting vector components of a predominant spin vector in a particle beam having a predominant spin orientation of the particles, with the spin detector arrangement comprising:
a spin rotator having a switchable coil, with the switchable coil having an axial direction and being aligned such that the particle beam passes through the switchable coil along the axial direction;
a deflection device connected downstream of the spin rotator, which deflects the path of the particle beam electrostatically by a deflection angle;
a spin detector connected downstream of the deflection device, which allows the detection of the perpendicular vector components of the predominant spin vector in the particle beam relative to the direction of motion of the particle beam; and
a switching unit connected to the switchable coil, which allows the switching of the excitation state of the coil,
wherein the spin detector successively measures two respective vector components of the predominating spin vector, with the coil of the spin rotator being switched by means of the switching unit into a first excitation state in the one measurement, and into a second excitation state in the other measurement.