Abstract
An ion source for studying low energy ion-molecule reactions is described. The ion source is equipped with a rf quadrupole mass filter which provides ionic species of masses up to 50 amu and delivers mass selected ion beams of energies from several tens of eV down to 1 eV or less. The beam intensity ranges from 10-9 A at high energy to 10-12 A at low energy.The energy profiles of the ion beam were measured using an energy analyzer of a stopping potential type. Results were further checked by the time of flight method. The spatial profiles of the beam were also measured.
