On the diffraction peak amplitude measured by neutron reverse time-of-flight (RTOF) diffractometry

For the first time, a detailed analysis of the diffraction peak amplitude dependence on the maximum neutron beam modulation frequency, measured by the reverse time-of-flight (RTOF) diffractometry method, has been carried out. It is shown that this dependence can be explained by a combination of the “collimation” effect due to neutron beam modulation by a Fourier chopper and the presence of a nonzero geometric component ΔdG of the peak width. A set of experimental data obtained on the Fourier diffractometers FSD, FSS, and HRFD confirmed this hypothesis and is in good agreement with the proposed model. An approach is proposed to optimize the relationship between intensity and resolution of a Fourier diffractometer.