EUV ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization and electron energy-loss spectra

Buchta, D.Krishnan, S. R.Brauer, Nils BenedictDrabbels, MarcelO'Keeffe, P.Devetta, M.Di Fraia, M.Callegari, C.Richter, R.Coreno, M.Prince, K. C.Steinkemeier, F.Moshammer, R.Mudrich, M.2013-06-232013-06-232013-06-23201310.1063/1.4818531https://infoscience.epfl.ch/handle/20.500.14299/92935WOS:000323928000027The ionization dynamics of pure He nanodroplets irradiated by EUV radiation is studied using Velocity-Map Imaging PhotoElectron-PhotoIon COincidence (VMI-PEPICO) spectroscopy. We present photoelectron energy spectra and angular distributions measured in coincidence with the most abundant ions He+, He+2 , and He+3. Surprisingly, below the autoionization threshold of He droplets we find indications for multiple excitation and subsequent ionization of the droplets by a Penning-like process. At high photon energies we evidence inelastic collisions of photoelectrons with the surrounding He atoms in the droplets.penning ionizationhelium dropletssynchrotronPEPICOEUV ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization and electron energy-loss spectratext::journal::journal article::research article