  A comparison is made between the three principal methods for analysis of
neutron and X-ray diffraction data from noble gas fluids by direct Fourier
transform. All three methods (standard Fourier transform, Lorch modification
and Soper-Barney modification) are used to analyse four different sets of
diffraction data from noble gas fluids. The results are compared to the
findings of a full-scale real space structure determination, namely Empirical
Potential Structure Refinement. Conclusions are drawn on the relative merits of
the three Fourier transform methods, what information can be reliably obtained
using each method, and which method is most suitable for analysis of different
kinds of diffraction data. The mathematical validity of the Lorch method is
critically analysed.
