Simulation of Spin-Axis Position Measurement of Superconducting Sphere Rotor by Fiber Optic Sensor

The reflective intensity modulated (RIM) fiber optic sensor is introduced for the measurement of superconducting sphere rotor spin-axis position in cryogenic instrument. A diffuse reflective rectangle pattern scribed on the circular flat surface at one end of the spin axis was used to modulate the reflective optical intensity on which the deviation value and direction of the spin-axis was determined. The relationship between the deviation of spin axis and the reflective optical intensity modulation is presented and some related factors are analyzed.