title: The design of double electrostatic-lens optics for resonance enhanced multiphoton ionization and photoelectron imaging experiments.
abstract: Compared to single ion/electron-optics for velocity-map imaging, a double-focusing lens assembly designed not only allows for mapping velocity imaging of photoelectrons but also allows for investigating the vibrational structure of the intermediate states of neutral species in resonance enhanced multiphoton ionization (REMPI) spectra. In this presentation, in order to record REMPI and photoelectron spectra separately, we have constructed a compact photoelectron velocity-map imaging (VMI) apparatus combined with an opposite linear Wiley-Mclaren time-of-flight mass spectrometer (TOFMS). A mass resolution (m/Δm) of ∼1300 for TOFMS and electron energy resolution (ΔE/E) of 2.4% for VMI have been achieved upon three-photon ionization of Xe atom at 258.00 nm laser wavelength. As a benchmark, in combination of one-color (1 + 1) REMPI and photoelectron imaging of benzene via 6(1) and 6(1)1(1) vibronic levels in the S1 state, the vibrational structures of the cation and photoelectron angular anisotropy are unraveled. In addition, two-color (1 + 1') REMPI and photoelectron imaging of aniline was used to complete the accurate measurement of ionization potential (62,271 ± 3 cm(-1)). The results suggest that the apparatus is a powerful tool for studying photoionization dynamics in the photoelectron imaging using vibrational-state selected excitation to the intermediate states of neutrals based on REMPI technique.
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Zehua
authors.initials: Z
authors.lastname: Qu
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Li
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Qin
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Guanxin
authors.initials: G
authors.lastname: Yao
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Xianyi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Cui