Effect of double charge exchange on the establishment of charge equilibrium in ion beams

The results of experimental measurements of the distributions of charge fractions $F_i$ in ion beams on passing through thin celluloid films differing in thickness are used to calculate the charge-exchange cross sections of high-speed ions with due regard for the transfer both of a single electron and of two electrons simultaneously. The results are presented of calculating the mean charges $\hat I$ and equilibrium target thickness $t_{\rm eq}$ for Be, B, N, and О ions differing in initial charges and moving with a velocity of $V=3.6$ a.u. It is demonstrated that allowing for the loss and capture of two electrons simultaneously accelerates the establishment of charge equilibrium.