Evolutions of the level of beam ion losses f_loss in n_single = 1, n_single = 2, n_single = 3, n_single = 4 simulations and multiple-n simulation with the same parameter β_h = 1.81%, υ_h = 2.55υ_A. Note that sum denotes the sum of loss over n_single = 1–4 modes, where every lost particle is calculated for one time.