Abstract

A time-of-flight mass spectrometer with a pulsed electron beam, delayed and pulsed extraction of the recoil ion is reported. This new technique is named as Delayed Extraction Time of Flight Mass Spectrometer (DEToF). The effectiveness of this technique is highlighted by studying the statistical decay of mono-cations over microsecond timescales from large molecules. Various details of the design and operation are performed in the context of electron impact ionization and fragmentation of few PAHs, naphthalene (C10H8), quinoline (C9H8N) and it isomer Isoquinoline (C9H8N) and are used as a test bench mark for large molecules fragmentation dynamics using DEToF. In this chapter we discuss the fragmentation dynamics of Naphthalene molecule and time evolution of various fragmentation channels of these PAH, explored using a rapid but delayed extraction of recoil ions. The temporal behavior of acetylene (C2H2), HCN, diacetylene (C4H2) and C2H2+HCN loss are observed and compared with the associated Arrhenius decay constant, internal energy and plasmon excitation energy.

Keywords: large molecule spectroscopy, delayed extraction time of flight, PAHs
