Knowledge Bank

An apparatus which combines the ability to take laser induced fluorescence (LIF) and time-of-flight (TOF) mass spectra has recently been put into operation in our laboratory. We have performed initial experiments on cluster species involving $NO+$ and $C6F6+$. Resonantly enhanced multiphoton ionization of NO produces cleanly $NO+$ in a supersonic jet expansion. Sampling of the expansion through a skimmer with a TOF mass spectrometer reveals that cluster species containing as many as 15 NO's and 20 Ar's can be grown from the isolated NO+ seed. For the van der Waals molecules $(C6F6)n+Rm$, the TOF mass spectrometry is combined with laser induced fluorescence (LIF) measurements prior to skimming the expansion. Features in the LIF spectra can thus be correlated to the species present in the jet as determined directly by the TOF analysis.