Recoil-ion momentum spectroscopy applied to study charge changing collisions

We describe a setup for performing recoil-ion momentum spectroscopy using a supersonic gas jet target (COLTRIMS) and a multi-hit detector that has been assembled in our laboratory. The apparatus will be used in the study of momentum distributions of recoil -ions and molecule dissociation fragments produced in collisions that involve charge-changing states in the projectile. We give a description of the different components of the system and the method we use to obtain the momentum distribution. To test the performance of the setup we performed measurements for the single capture collision of 3He2+ projectiles incident on a He target. The resolution of our spectrometer allowed the identification of capture to ground and excited states. We present state-selective cross sections for capture in the projectile energy range from 40 to 300 keV.