Eur. Phys. J. D 24, 393-396 (2003)
https://doi.org/10.1140/epjd/e2003-00174-9

Dynamical aspects of thermionic emission of C₆₀ studied by 3D imaging

¹ Laboratoire de Spectrométrie Ionique et Moléculaire (UMR 5579) , CNRS and Université Lyon 1, bâtiment A. Kastler, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex, France
² School of Physics and Engineering Physics, Göteborg University and Chalmers University of Technology, 41296 Göteborg, Sweden

Corresponding author: ^a bordas@lasim.univ-lyon1.fr

Received: 10 September 2002
Published online: 3 July 2003

Abstract

We present the first experimental results of the time-dependent photoelectron spectrum observed in thermionic emission of hot C₆₀ excited by multiphoton absorption. Time resolved velocity-map imaging is used to record photoelectron spectra. As opposed to the evolution of the total photoelectron current that follows a power law as a function of the delay after excitation, it is shown that the photoelectron spectrum bears precise information on the degree of excitation of the ensemble of clusters. The effective temperature deduced from the experimental spectrum is found to be directly related to the average internal energy in the initial step of the decay, while after typically 1 μs the photoelectron spectrum is almost independent on the initial excitation process. The subsequent evolution of the spectrum as a function of the time-delay after excitation is found to be very slow.