ZEKE spectroscopy: High-resolution laser spectroscopy in a modified time-of-flight mass spectrometer

In this article, a method for high-resolution laser spectroscopy of ions-termed ZEro-Kinetic Energy spectroscopy (ZEKE)-is reviewed. Emphasis will be put on a more recent, mass-selective version (mass-analyzed ZEKE). A detailed description of the apparatus, designed and built at the Technische Universitat Munchen, will first be given, In a second part, we outline two applications which are particularly suited to illustrate the potential of the method, We hope to demonstrate to the mass spectrometry community the close connection between a ZEKE spectrometer and a conventional reflectron time-of-flight mass spectrometer (TOE-MS), Adding one single electrostatic field lens to the extraction field region of a TOE-MS allows to go far beyond mass analysis, distinguishing, for example, between isomeric structures or determining the geometric structure of molecular ions.