Charge-changing cross sections (CCCSs) of ${}^{18}\mathrm{O}$ on carbon (C) and lead (Pb) targets have been measured with an uncertainty of less than 4% near 370 MeV/nucleon. We evaluate the contributions of nucleon-nucleon and electromagnetic (EM) interactions to CCCSs by considering the direct proton removal process, the charged particle evaporation (CPE) after neutron removal, and the EM excitation. We conclude that the CPE accounts for 12.3 and 5% of CCCSs on C and Pb, respectively. Only less than 1% of CCCSs of ${}^{18}\mathrm{O}$ is attributed to the EM excitation. Further investigation of projectiles from ${}^{18}\mathrm{O}$ to ${}^{197}\mathrm{Au}$ on C, silver (Ag), and Pb targets at 300 and 900 MeV/nucleon shows that the EM contribution to CCCSs on Ag and Pb increases with projectile mass numbers and incident energies, and can reach 10% for ${}^{197}\mathrm{Au}$ on Pb at 900 MeV/nucleon. In contrast, the EM contribution to CCCS is negligible for all projectiles on C at both energies.

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• Charge-exchange reactions
• Nuclear fragmentation
• Nuclear reactions
• 6 ≤ A ≤ 19
• Radioactive beams