A 4-PI RECOIL-ION ELECTRON MOMENTUM ANALYZER - A HIGH-RESOLUTION MICROSCOPE FOR THE INVESTIGATION OF THE DYNAMICS OF ATOMIC, MOLECULAR AND NUCLEAR-REACTIONS

A high-resolution recoil-ion momentum spectrometer based on a precoole d localized supersonic jet target (COLTRIMS) has been combined with a novel low-energy electron analyzer with 4 pi solid angle for electrons with energies E(e) less than or similar to 30 eV including E(e) = 0 e V. Thus, three recoil-ion momentum components, the recoil-ion charge s tate and three momentum components of one electron emitted in any coll ision-induced ionization reaction are measured simultaneously with a c oincidence efficiency of 28%. In order to accept large recoil-ion long itudinal momenta (along the beam) of p(R parallel to) less than or equ al to 160 a.u. and simultaneously guarantee a superior resolution in t his direction (Delta P-R parallel to less than or equal to +/-0.08 a.u .), recoil ions are extracted in the longitudinal direction different from all former concepts. Test measurements, details on the present de sign and results of a kinematically complete experiment for single ion ization are presented and possible further improvements are discussed. The future potential of such spectrometers for the investigation of c ollision-induced atomic many-particle reactions, the ''Coulomb-explosi on'' of molecules and the spectroscopy of electronic states in heavy f ew-electron systems is illustrated. Similar techniques might be used t o measure angular correlations and even the neutrino mass in P-decay e xperiments.