Development of a TOF Mass Spectrometer Using a Sector Magnet and Detection of Cluster Dissociations.

In the studies on dissociation patterns of clusters using a single focusing mass spectrometer, product ions decomposed between a main slit and an entrance of a magnet appear in mass spectra at mass Map= Mpro2/Mpre, whereMpro denotes the mass of product ions and Mpre; mass of precursor ions. In the case of decomposition from cluster size nto n-m(n>m), the product ions appear at size of (n-m)2/n. When n is much larger than m, (n-m)2/n is very close to (n-2m), and it is difficult to resolve the dissociated n and undissociat ed (n-2m) cluster ions. In order to study on decomposition patterns of clusters, we attached the TOF function to the sector type mass spectrometer and detected product ions. We attached the chopper in front of the main slit to get the pulsed beam and use silver clusters as the sample.