title: He I ultraviolet photoelectron spectroscopy of benzene and pyridine in supersonic molecular beams using photoelectron imaging.
abstract: We performed He I ultraviolet photoelectron spectroscopy (UPS) of jet-cooled aromatic molecules using a newly developed photoelectron imaging (PEI) spectrometer. The PEI spectrometer can measure photoelectron spectra and photoelectron angular distributions at a considerably higher efficiency than a conventional spectrometer that uses a hemispherical energy analyzer. One technical problem with PEI is its relatively high susceptibility to background electrons generated by scattered He I radiation. To reduce this problem, we designed a new electrostatic lens that intercepts background photoelectrons emitted from the repeller plate toward the imaging detector. An energy resolution (ΔE/E) of 0.735% at E = 5.461 eV is demonstrated with He I radiation. The energy resolution is limited by the size of the ionization region. Trajectory calculations indicate that the system is capable of achieving an energy resolution of 0.04% with a laser if the imaging resolution is not limited. Experimental results are presented for jet-cooled benzene and pyridine, and they are compared with results in the literature.
authors.affiliation: Chemical Dynamics Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako 351-0198, Japan.
authors.forename: Suet-Yi
authors.initials: SY
authors.lastname: Liu
authors.forename: Koutayba
authors.initials: K
authors.lastname: Alnama
authors.forename: Jun
authors.initials: J
authors.lastname: Matsumoto
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nishizawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kohguchi
authors.forename: Yuan-Pern
authors.initials: YP
authors.lastname: Lee
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D001554:Benzene / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D056951:Photoelectron Spectroscopy / Q000295:instrumentation; D011725:Pyridines / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation
chemical_list: D005609:Free Radicals; D011725:Pyridines; D001554:Benzene; C023666:pyridine