U.Berzinsh , J.Klavins , J.Alnis , M.Eklund , and H.Helm , 2014.02.07

1. “Properties of Atoms in the Negative Ion and Femtosecond Laser Radiation Interaction” the Collaboration between University of Latvia and Freiburg University financed via Baltic-German University Liaison Office. U.Berzinsh, J.Klavins, J.Alnis, M.Eklund, and H.Helm, 2014.02.07 Riga, LU 72 scientificconference

2. Abstract • This was first collaboration between our two institutes and main target for Latvian team was to participate in some experiment with negative ions and have hands on femtosecond laser used in Freiburg. Recently very interesting experiment on carbon atoms was performed by using this laser, and by using the carbon anion beam for formation of carbon atom beam [1]. During our visit the experiment for measurement of beta coefficient in photo detachment of C- was set up. • Important part for this project was to establish closer contacts between our two institutes, and search for potential future collaboration. • This project of the Baltic-German University Liaison Office is supported by the German Academic Exchange Service (DAAD) with funds from the Foreign Office of the Federal Republic Germany. • [1] H.Hultgren, M.Eklund, D.Hanstorp and I.Yu.Kiyan. Electron dynamics in the ground state of a laser-generated carbon atom. Physical Review A 87 (3) (2013)

3. Outlook • Background (Gothenburg Freiburg Riga) • Group in Freiburg, roots in Gothenburg • Recent experiment, triedtopublish in Nature • Femtosecond laser, compexity • Baltic-German University Liaison Officeproject, we won • Further Collaboration, conference/summerschool 2014

4.   Strong Laser FieldsPeople

5. Electron dynamics in the ground state of a laser-generated carbon atom, 2013 • A real-time observation of electron motion in the ground state of the carbon atom is presented. • A wave packet is created in the ground triplet state of the atom via photodetachment of its negative ion in a strong laser field. • Its dynamics is probed using the selectivity of strong-field ionization to orbital alignment in combination with an electron-imaging technique. • A strong temporal modulation in the photoelectron yield at high kinetic energies is observed, which reveals a periodic motion of the electron cloud in the atom.

6. Experimental setup

7. Images of photoelectrons recorded at pump-probe time delays of 2000 fs (a), 2300 fs (b), and 2600 fs (c). p and p⊥denote the electron momentum components parallel and perpendicular to the polarization axis of the probe beam, represented by the arrow in (d). The two rectangles shown in (d) represent the area over which the electron yield was integrated

8. Laser consistof:

9. PulseStrecher&Isolatorand PulseCompressor

10. Wissenschaftszweig (Bitte zutreffendes anfärben) • X Mathematik und Naturwissenschaften • Rechts-, Wirtschafts- und Sozialwissenschaften • Sprach- und Kulturwissenschaften • Ingenieurswissenschaften • Veterinärmedizin, Agrar-, Forst- und Ernährungswissenschaften, Ökologie • Humanmedizin • Kunst, Musik und Sportwissenschaften

11. Furthercolaboration Dear Uldis, Feel free to give a presentation on February 7th, I will be happy to correct / add to your draft once you send me your version. Concerning the summerschool I would be happy to contribute.  Topics I have given in previous summer schools are: - Photoionization and photodissociation  ( 6 hours ) - Imaging of electrons, atoms, molecules, and fields (4 hours ) - High resolution frequency measurement / atomic clocks (4 hours)  Concerning possible dates:   After April 21 or second half of August 2014 are possible. Best wishes, Hanspeter