DIPLOMA - AN EXPERIMENTAL SYSTEM TO STUDY MEV AND KEV PARTICLE-INDUCED AND PHOTON-INDUCED DESORPTION OF MOLECULES

A high resolution time-of-flight mass spectrometer that analyzes secon dary ions produced when samples are bombarded with MeV and keV ions an d ultraviolet photons is described. The flexibility of the system is d emonstrated by showing results from several varied experiments includi ng high resolution mass spectra of molecular ions desorbed from a reni n substrate sample by MeV and keV ions, a multiphoton ionization spect rum of gas-phase benzene, and a matrix assisted laser desorption spect rum of a glycoprotein. The keV ion source is useful for secondary ion mass spectrometry work, for imaging, and for micromachining of surface s. By using the attached electrostatic ion reflector metastable decomp osition of various molecular and fragment ions can be studied. (C) 199 5 American Vacuum Society.