A system for correlated fragment detection in dissociation experiments

Abstract

We describe a detector system for the study of the dissociation dynamics of small molecules, clusters or molecular ions. The system is based on a two-dimensional multiparticle detector which allows the position-sensitive and time-correlated detection of all fragments produced in one particular dissociation process. As a test example we discuss the double ionization and ensueing fragmentation of H 2 by fast H + and He + ions, in which case our detector allows an absolute measurement of the dissociation energy of the two correlated H +-fragments. The results are in excellent agreement with the prediction of a Franck-Condon calculation.