Matching of beam handling and detection system for optimum resolution in nuclear physics experiments

Abstract A general formulation for achieving optimal resolution in nuclear physics experiments with particle beams is presented. Examples are given for measuring Q -values, cm-scattering angles, and excitation functions with e.g. a magnetic or a time-of-flight spectrometer. By treating the beam handling and the spectrometer as a unit many usual causes for poor resolution like the energy spread of the beam or the angular acceptance of the detection system can be eliminated without loss of intensity. The requirements on the beam handling are easy to fulfill. Indeed most requirements are met by an analyzing magnet and two quadrupole doublets as installed at many accelerators.