Probehead Of An NMR-MAS Apparatus With A Device For Determining The Angle Between The MAS Rotor And The Static Magnetic Field

A probehead of a Nuclear Magnetic Resonance (NMR)-Magic Angle Spinning (MAS) apparatus, which is introduced in operation in a magnet system that generates a homogeneous static magnetic field B0 along a z-axis, the probehead comprising:

• a measurement sample with a rotation axis that lies in an xz-plane and is tilted at an angle θ>0 with respect to the z-axis, wherein the angle θ is configured to adjust by tilting the rotation axis around a tilt axis parallel to a y-axis to reach a tilt at which the angle θ equals a target angle θtarget, and wherein z=0 is defined as a point of intersection of the rotation axis and the z-axis at the angle θ=θtarget;
• and
• an angle measurement apparatus that generates a signal S(θ) dependent on the angle θ, the angle measurement apparatus comprising a plurality of sensor elements wherein each sensor element of the plurality of sensor elements generates a sensor signal that depends on the amplitude of the homogenous static magnetic field B0 and the angular orientation between the homogenous static magnetic field B0 and a respective sensitivity vector associated with the sensor element, wherein each sensor element generates a maximum sensor signal when the respective sensitivity vector is oriented orthogonal to the homogenous static magnetic field B0, and wherein the signal S(θ) is a function of at least two sensor signals from at least two sensor elements associated with at least two respective sensitivity vectors, each of the at least two respective sensitivity vectors being oriented at an angle αi between 5° and 175° with respect to the z-axis, and wherein the at least two respective sensitivity vectors are oriented at an angle β>10° with respect to each other.