Charge Exchange of Carbon and Nitrogen Ions in Nitrogen Gas

Electron loss and capture cross section of carbon and nitrogen ions were measured at 3.5~7 MeV/nucl., i.e. velocities of 2.6~3.7×109 cm/sec in nitrogen gas. Cross sections obtained were σ45, σ56, σ65, for carbon ions and ∑\limitsk=57σ4k for nitrogen ions when they passed through the charge exchange (collision) chamber. Cross sections of single electron loss σ45 and σ56 are nearly proportional to v0/v and those of single electron capture σ65 are proportional to (v0/v)6, where v0 is the atomic unit of velocity and v is ion velocity. This paper reports also on the comparison between the beam attenuation of N4+ ions, which were accelerated in the IPCR 160 cm cyclotron, caused by charge exchange at collisions with residual gases, and the attenuation calculated from measured ∑\limitsk=57σ4k in nitrogen gas.