  A novel fusion product separator, based on a gas-filled 8 T superconducting
solenoid has been developed at the Australian National University. Though the
transmission efficiency of the solenoid is very high, precision cross section
measurements require knowledge of the angular distribution of the evaporation
residues. A method has been developed to deduce the angular distribution of the
evaporation residues from the laboratory-frame velocity distribution of the
evaporation residues measured at the exit of the separator. The features of
this method are presented, focusing on the example of $^{34}$S+$^{89}$Y which
is compared to an independent measurement of the angular distribution. The
establishment of this method now allows the novel solenoidal separator to be
used to obtain reliable, precision fusion cross-sections.
