An Electrostatic Quadrupole Doublet with an Integrated Steerer

Electrostatic storage rings have proven to be a valuable tool for atomic and molecular physics. Due to the mass independence of the electrostatic rigidity, different kinds of ions with the same charge/energy ratio from light protons to very heavy bio molecules can be stored with the same field setup. The transverse dimensions of the circulating beam are controlled by electrostatic quadrupole doublets or triplets. It is essential that the fields in these lenses can be adjusted independently one from another to allow an exact control of the stored ions. In this paper, first an overview of the principle of electrostatic lenses is given. After a short discussion of fringe field effects, the results of field calculations are presented and the final layout of an electrostatic quadrupole doublet with an integrated steerer as it will be used in future electrostatic storage rings in Frankfurt and Heidelberg is discussed