On the target thickness to attain equilibrium charge distribution in a beam of fast ions

Nonequilibrium charge states of light ions penetrating through carbon films

“…Its distinctive feature is the appearance of several charge components after pene tration through the target at the given ion beam energy. However, calculations performed according to for mula (3) agree with the experimental data [11,12] if the dependence of coefficient α on the initial charge of a bombarding ion is taken into account:…”

“…This value can be determined by estimat ing the equilibrium target thickness t eq . According to relationship (3), the target thickness corresponding to the formation of charge equilibrium can be estimated only if the mean charge differs from by no more than 3% [11]:…”

“…The average charge is = i 0 at t = 0. The experimental data designated by symbols ᭺ and ᮀ (helium) and , ᭹, ᭡, and ᭢ (nitrogen) [11][12][13] were obtained at the ion velocity V = 8 × 10 8 cm/s (Е = 0.33 MeV/nucleon). The value corresponding to * [6] was measured at the ion velocity V = 8.5 × 10 8 cm/s (Е = 0.375 MeV/nucleon).…”

“…The two charge components have identical α coefficients. In the given approximation, this parameter is the sum of the electron loss and cap ture cross sections [11].…”

“…In this study, a method based on available experi mental data [11][12][13] is proposed for calculating the mean nonequilibrium charges of helium, carbon, and nitrogen ions with different energies in the process of equilibrium establishment between charge fractions upon ion beam penetration through carbon films.…”