A DOUBLE TRIPLE TIME-OF-FLIGHT MASS-SPECTROMETER FOR THE STUDY OF PHOTOPROCESSES IN CLUSTERS, OR HOW TO PRODUCE CLUSTER IONS WITH DIFFERENT TEMPERATURES

An apparatus is described for the measurement of photo processes in mass-selected cluster ions. A gridless reflectron type of time-of-flight (TOF) mass spectrometer is used to select an ion of known mass. The selected ion is photoexcited with a pulsed dye laser. The charged fragments are mass separated in a second linear TOF. A new combination of reflectron and linear TOF is described, which allows one to measure the complete photofragment mass distribution over an arbitrary large mass range for each laser shot, which was not possible earlier. It is discussed how clusters with different temperatures can be prepared. The first measurement of a temperature-dependent effect for mass-selected free cluster ions is presented.