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Cari tutti,

vi invitiamo a partecipare all'incontro “SMeet” - Science Sharing Meetings, previsto per venerdì 23 Aprile 2021 ore 11:30 (ammissione in stanza disponibile dalle 11:20) che, attenendoci al protocollo relativo all’emergenza COVID-19, si terrà online tramite la piattaforma Microsoft Teams attraverso il seguente link:

http://bit.ly/SMEET-IMM

Il meeting prevede:

· Speaker: Giuseppe Mario Caruso

· Chair: Mario Scuderi

· Titolo: Probing the ultrafast dynamics with a sub-nanometric and sub-picosecond spatiotemporal resolution: Ultrafast Electron Microscopy

· Abstract: Electron Microscopy (EM) is a powerful and versatile technique allowing to obtainmorphological, structural, chemical and field information of specimens at the nanoscale [1].Nevertheless, despite the implementation of fastest cameras, the investigation of thematerial dynamics is limited to the millisecond timescale. Ultrafast EM overcomes thislimitation. Combining the excellent temporal properties of ultrafast lasers or ultrafastelectrostatic beam blankers it is possible to trigger a pulsed electron beam with ultrashortelectron pulses and push the temporal resolution of the instrument to the picosecondtimescale and beyond.Several strategies to investigate material dynamics at the nanoscale with a sub-picosecondtime resolution will be presented, in both Scanning Electron Microscopy (SEM) andTransmission Electron Microscopy (TEM). Ultrafast Scanning Electron Microscopy (USEM),firstly developed in CALTECH [2] has been improved in AMOLF afterwards, allowing TimeResolved Cathodoluminescence (TR-CL) spectroscopy to acquire CL decay traces and theautocorrelation function g(2) of the CL signal [3]. The first Ultrafast Transmission ElectronMicroscope based on a Cold FEG emission source, recently developed at CEMES-CNRS [4],allows to perform time-resolved ultrafast pump-probe TEM experiment exploiting a highcoherent ultrafast electron beam [5]. We will show the performances of such an instrument aswell as the first experimental results obtained by Electron Energy Gain Spectroscopy (EEGS).Some outlooks on future applications will be given.

References
1. Williams, D. B. & Carter, C. B. Transmission Electron Microscopy: A Textbook forMaterials Science. (Springer US, 2009).
2. Yang, D.-S., Mohammed, O. F. & Zewail, A. H. Scanning ultrafast electron microscopy.Proc. Natl. Acad. Sci. 107, 14993–14998 (2010).
3. Meuret, S. et al. Complementary cathodoluminescence lifetime imaging configurationsin a scanning electron microscope. Ultramicroscopy 197, 28–38 (2019).
4. Caruso, G. M., Houdellier, F., Abeilhou, P. & Arbouet, A. Development of an ultrafastelectron source based on a cold-field emission gun for ultrafast coherent TEM. Appl.Phys. Lett. 111, 023101 (2017).
5. Houdellier, F., Caruso, G. M., Weber, S., Kociak, M. & Arbouet, A. Development of a highbrightness ultrafast Transmission Electron Microscope based on a laser-driven cold fieldemission source. Ultramicroscopy doi:10.1016/j.ultramic.2017.12.015

Vi aspettiamo numerosi,

Saluti

SMeet – Comitato Organizzativo
smeet[@]imm.cnr.it
Web-page: https://hq.imm.cnr.it/smeet-science-sharing-meetings