An indigenous cluster beam apparatus with a reflectron time-of-flight massspectrometer

The design and fabrication of a Smalley-type cluster source in combination with a reflectron based time-of-flight (TOF) mass spectrometer are reported . The generation of clusters is based on supersonic jet expansion of the sa mpling plume. Sample cells for both liquid and solid targets developed for this purpose are described. Two pulsed Nd-YAG lasers are used in tandem, on e (532 nm) for target vapourization and the other (355 nm) for cluster ioni zation. Methanol clusters of nuclearity up to 14 (mass 500 amu) were produc ed from liquid methanol as the test sample. The clusters were detected with a mass resolution of similar to 2500 in the R-TOF geometry. Carbon cluster s up to a nuclearity of 28 were obtained using a polyimide target. The util ity of the instrument is demonstrated by carrying out experiments to genera te mixed clusters from alcohol mixtures.