  The MAGNEX magnetic spectrometer is used in the experimental measurements of
Double Charge Exchange and Multi-Nucleon Transfer reactions induced by heavy
ions within the NUMEN project. These processes are characterized by small cross
sections under a large background due to other reaction channels. Therefore an
accurate control of the signal to background ratio is mandatory. In this
article, the determination of the MAGNEX spectrometer background contribution
on cross section measurements is presented by applying a suitable analysis to
quantify the limits of the adopted particle identification technique. The
method is discussed considering the 116Cd(20Ne,20O)116Sn Double Charge Exchange
reaction data, however it can be applied to any other reaction channel of
interest.
