Photoionization Analysis by Mass Spectroscopy

Critical review of ultraviolet photoabsorption cross sections for molecules of astrophysical and aeronomic interest

“…The photoionization efficiency has been measured with mass spectrometric PHOTOABSORPTION CROSS SECTIONS OF MOLECULES 63 techniques by Weissler et al [1959], and by Reese and Rosenstock [1966]. The former results were obtained with a line emission source, the latter with continuum light sources at an instrumental resolution of 2 A.…”

“…Relative ionization cross sections, i.e., the photoionization efficiency (PE), have been measured by and Weissler et al [1959].…”

The band spectrum of carbon monoxide

“…[254] and Henning [91]. 3.19. P, Q, R, S, T-X'S + Tanaka Systems (800-630 A) R Among numerous absorption bands which make up several Rydberg series, Tanaka [254] Weissler et al [270] have observed the P state and the S (or T) state by photoionization. Kaneko [124] has observed these in electron impact.…”

“…The ionization of the 3a-electron lias not been observed. There is some evidence for a state of CO + at 25.6 eV (±0.5 eV) from electron impact [151] and photoionization [270] Codling [42] has recently observed structure in the 500 A region which appears to include a 4 The three lowest IP have been determined experimentally from Rydberg series limits and electronic spectra of CO + (sec. 5.3).…”

Formation of O−2 in charge transfer collisions of fast molecular hydrogen ions with O2 molecules

“…In collisions with the bare proton the occurrence of O-must be ascribed to the reaction channel O* ~ O + + O-, being analogous with the process of ion-pair formation after electron impact [41] or photon absorption [42], which both have their onset at 17.25 eV -above the first ionization potential of Oz (12.059 eV [43]) and below the threshold for dissociative ionization of 18.73 eV [44,45]. Under the impact of the molecular ions the origin of O-becomes ambiguous, since it might as well stem from an electron transfer if the intermediate 02 is simultaneously excited to a repulsive state and undergoes fragmentation straight afterwards.…”