Measuring precise fusion cross sections using an 8T superconducting solenoid

A novel fusion-evaporation residue separator based on a gas-filled superconducting solenoid has been developed at the Australian National University. Though the transmission efficiency of the solenoid is very high, precision cross sections measurements require this efficiency to be accurately known and vitally, requires knowledge of the angular distribution of the evaporation residues. We have developed a method to deduce the angular distribution of the evaporation residues from the laboratory-frame velocity distribution of the evaporation residues transmitted by the solenoid. The method will be discussed, focusing on benchmarking examples for S-34 + Y-89, where the angular distributions have been independently measured using a velocity filter (A. Mukherjee et al., Phys. Rev. C. 66, 034607 (2002)). The establishment of this method now allows the novel solenoidal separator to be used to obtain reliable, precise fusion cross-sections.