Calculations on the possibility of the simultaneous acceleration of ions with different charge states in a RFQ

Direct injection into a RFQ without mass or charge separation is discussed especially in those cases, where a larger number of accelerated ions or higher beam currents are required. Assuming an electrostatic ion-source extraction system and an Einzellens, e.g. for focusing the beam into the RFQ, all charge states are offered but with different input energies corresponding to their charge to mass ratio. Particle dynamics calculations show, that ions with higher charge states than the design value are accelerated to the final energy with good beam quality whereas ions with lower charge states are only partly accelerated, partly drifting or are lost. Results of calculations three different cases are presented and discussed for different ion species