Charge-changing collisions of 2.0-MeV nitrogen ions through N2 gas

The equilibrium charge distributions resulting from 2.0-MeV nitrogen ions passing through an N2 gaseous target are presented. The modified slope method is developed for determining charge-changing cross sections from the data of non-equilibrium charge fractions at low pressures. By changing the initial charge state of the projectile ions, some of the cross sections of single and double electron capture and loss were determined. The measured cross sections of single electron capture are in good agreement with the theoretical calculations of Bohr-Lindhard and also with the semiempirical values of Nikolaev et al. The measured cross sections of single electron loss are quite different from the theoretical calculations. (auth.)