title: A combined electron-ion spectrometer for studying complete kinematics of molecular dissociation upon shell selective ionization.
abstract: A combined electron-ion spectrometer has been built to study dissociation kinematics of molecular ions upon various electronic decay processes ensuing from ionization of neutral molecules. The apparatus can be used with various ionization agents. Ion time-of-flight (ToF) spectra arising from various electronic decay processes are acquired by triggering the ToF measurement in coincidence with energy analyzed electrons. The design and the performance of the spectrometer in a photoionization experiment is presented in detail. Electron spectra and ion time of flight spectra resulting from valence and 2p1∕2 ionization of Argon and those from valence ionization of CO are presented to demonstrate the capability of the instrument. The fragment ion spectra show remarkable differences (both kinematic and cross sectional) dependent on the energy of the ejected electron, corresponding to various electron loss and decay mechanisms in dissociative photoionization of molecules.
authors.affiliation: Physical Research Laboratory, Navrangpura, Ahmedabad 380009, India. koushik@prl.res.in
authors.forename: K
authors.initials: K
authors.lastname: Saha
authors.forename: S B
authors.initials: SB
authors.lastname: Banerjee
authors.forename: B
authors.initials: B
authors.lastname: Bapat