The Neumark Group
Department of Chemistry, University of California Berkeley
and Chemical Science Division, Lawrence Berkeley National Laboratory
Slow photoelectron velocity-map imaging spectroscopy
Fast beam translational spectroscopy
Femtosecond Time-resolved photoelectron imaging
Molecular beam reactive scattering and photodissociation
Spectroscopy and dynamics in helium droplets
Attosecond spectroscopy
Spectroscopy and dynamics in liquid microjets
Slow Photoelectron Velocity-Map Imaging (SEVI)
Synopsis:
SEVI is a variant of the convential anion photoelectron spectroscopy which combines a velocity-map imaging (VMI) detection scheme
and tunable photodetachment energy. The mass-selected anions are photodetached at energies 0.01-0.5 eV above threshold and the resulting
photoelectrons are collected using relatively low extraction voltages, with the goal of selectively detecting slow electrons with high efficiency
and enlarging their image on the detector. At each wavelength, one obtains a high resolution (up to 1 cm-1) photoelectron spectrum over
a limited range of electron kinetic energy as well as the photoelectron angular distributions.
The SEVI spectra give the electronic and vibrational energy elevels of the neutral molecule at high-resolution. In combination with ab initio
electronic structure calculations and Franck-Condon simulations, the SEVI experiment yields information on the geometry, vibrational frequencies
and electronic structure of both the anion and neutral states.
Molecules studied:
Small organic radicals: alkoxy radicals (RO), vinoxy, HCO2, etc
van der Waals complexes: ClH2, FCH4, ClCH4, ArO, KrO, etc.
Interstellar molecules: CnH, CnH2, CnO, CnN, CnS, etc.
Transition metal and semi-conductor clusters
Project members:
Recent publications:
♦ "Slow photoelectron velocity-map imaging spectroscopy of C3O- and C3S-," E. Garand, T. I. Yacovitch, and D. M. Neumark, J. Chem. Phys. 131, 054312 (2009). pdf
♦ "Slow photoelectron velocity-map imaging spectroscopy of the vinoxide anion" T. I. Yacovitch, E. Garand, and D. M. Neumark, J. Chem. Phys. 130, 244309 (2009). pdf
♦ "Study of ArO- and ArO via slow photoelectron velocity-map imaging spectroscopy and ab initio calculations" E. Garand, A. A. Buchachenko, T. I. Yacovitch, M. M. Szczesniak, G. Chalasinski and D. M. Neumark, J. Phys. Chem. A 113, 4631 (2009). pdf
Additional information:
For a recent review, see:
♦ "Slow electron velocity-map imaging of negative ions: Applications to spectroscopy and dynamics" D. M. Neumark, J. Phys. Chem. A 112, 13287 (2008). pdf
