POSITION-SENSITIVE TIME-OF-FLIGHT MASS-SPECTROMETER USING A FAST OPTICAL IMAGING TECHNIQUE

A simple position-sensitive time-of-flight mass spectrometer has been developed with an aid of a gatable image intensifier. This spectrometer is a display-type analyzer allowing simultaneous measurements of the mass, speed, and angular distributions. The apparatus demonstrates a time resolution of 30 ns, a mass resolution over 125, and a spatial resolution over 60 in a multiphoton ionization experiment of NO molecules. The single-ion counting technique employed can detect a low-energy (approximately 100 meV) photofragment distribution without suffering from Coulombic repulsion.