Figure 13
The normalized visibility V of the intensity modulation as a function of the radial distance from the detector centre rD. V was calculated with equation (57) for a pinhole radius of R = 0.5 mm. (a) Modulation visibility with and without the first shifter. If the pinhole is smaller than the first loop of the shifter coil, the magnetic field of Sh1 does not affect the neutrons, as if no shifter were present. (b) V for different values of spin echo length. |