title: A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions.
abstract: We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10(-1) mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.
authors.affiliation: Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: C A
authors.initials: CA
authors.lastname: Arrell
authors.affiliation: Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Ojeda
authors.affiliation: Physics Department, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Sabbar
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: W A
authors.initials: WA
authors.lastname: Okell
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: T
authors.initials: T
authors.lastname: Witting
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: T
authors.initials: T
authors.lastname: Siegel
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: Z
authors.initials: Z
authors.lastname: Diveki
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Hutchinson
authors.affiliation: Physics Department, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Gallmann
authors.affiliation: Physics Department, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: U
authors.initials: U
authors.lastname: Keller
authors.affiliation: Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: van Mourik
authors.affiliation: Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX, United Kingdom.
authors.forename: R T
authors.initials: RT
authors.lastname: Chapman
authors.affiliation: Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Cacho
authors.affiliation: Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX, United Kingdom.
authors.forename: N
authors.initials: N
authors.lastname: Rodrigues
authors.affiliation: Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX, United Kingdom.
authors.forename: I C E
authors.initials: IC
authors.lastname: Turcu
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: J W G
authors.initials: JW
authors.lastname: Tisch
authors.affiliation: Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX, United Kingdom.
authors.forename: E
authors.initials: E
authors.lastname: Springate
authors.affiliation: Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: J P
authors.initials: JP
authors.lastname: Marangos
authors.affiliation: Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Chergui
mesh_terms: D002138:Calibration; D004867:Equipment Design; D056951:Photoelectron Spectroscopy / Q000295:instrumentation*; D012996:Solutions / Q000737:chemistry*; D013997:Time Factors; D014466:Ultraviolet Rays; D014618:Vacuum
chemical_list: D012996:Solutions