Laser-induced electron emission from a tungsten nanotip: identifying above threshold photoemission using energy-resolved laser power dependencies

We present an experiment studying the interaction of a strongly focused 25 fs laser pulse with a tungsten nanotip, investigating the different regimes of laser-induced electron emission. We study the dependence of the electron yield with respect to the static electric field applied to the tip. Photoelectron spectra are recorded using a retarding field spectrometer and peaks separated by the photon energy are observed with a 45 % contrast. They are a clear signature of above threshold photoemission (ATP), and are confirmed by extensive spectrally resolved studies of the laser power dependence. Understanding these mechanisms opens the route to control experiment in the strong-field regime on nanoscale objects.Comment: 9 pages, 6 figure

Q-DEPENDENCE OF THE DOUBLE CAPTURE CROSS SECTIONS MEASURED BY ELECTRON SPECTROSCOPY AT 10 qkeV (q = 4-8). COMPARISON WITH OTHER EXPERIMENTAL DATA

Les sections efficaces de double capture dans des états autoionisants ont été mesurées par spectroscopie électronique. On montre qu'elles sont indépendantes du coeur de l'ion multichargé. Nos résultats sont comparés avec toutes les autres valeurs publiées à ce jour et obtenues à 10 qkeV.The q dependence of cross sections for double capture into autoionising states has been investigated by electron spectroscopy. It is shown that they are independent o f the ionic core. Our results are compared with all other available experimental data obtained at 10 qkeV collision energy