KINEMATICALLY COMPLETE EXPERIMENTS USING COLD TARGET RECOIL ION MOMENTUM SPECTROSCOPY

Cold Target Recoil Ion Momentum Spectroscopy allows the detection of t he three-dimensional momentum vector of the recoiling product ion from ion, electron or photon atom collisions with 4 pi solid angle and hig h resolution. It can be combined with large area position-sensitive de tectors for electron detection or measurement of the projectile charge -state and scattering angle. Such 'reaction microscopes' cover the ful l correlated momentum space of all fragments of an atomic reaction yie lding kinematically complete information for each reaction event. For the first time in atomic collision physics fully differential data bec ame available in the sense that not only the momenta of all fragments, but also the complete momentum space is observed in one experiment. R ecent results achieved with this new technique for slow p-He collision s and threshold photo ionization of He will be discussed.