The Photon Day May 4th 2017

  • Date: –12:00
  • Location: Ångströmlaboratoriet, Lägerhyddsvägen 1 The Hägg lecture hall
  • Contact person: Olle Björneholm
  • Seminarium

The Center for Photon Science at Uppsala University welcomes you to the Photon Day!

To promote photon sciences at UU, we invite you to two inspiring talks, one by Prof. Anne L’Huillier, world-leading laser physicist from Lund, and the other by Dr. Max Hantke, winner of the 2017 "Uppsala Photon Science Award” ("Årets Ljushuvud-priset”).

Preliminary programme:

10.00 Coffee outside the lecture hall
10.15 Welcome and introduction

Prof. Anne L’Huillier, Department of Physics, Lund University, Sweden: From extreme nonlinear optics to ultrafast atomic physics

Abstract: The interaction of atoms with intense laser radiation leads to the generation of high-order harmonics of the laser field. In the time domain, this corresponds to a train of pulses in the extreme ultraviolet range and with attosecond duration. The short pulse duration and broad bandwidth of attosecond pulses allow us to measure the phase and amplitude of electronic wave packets created by photoionization. This gives us access to the temporal dynamics of the process that led to this wave-packet. This presentation will introduce the physics of high-order harmonic generation and attosecond pulses and describe applications concerning photoionization dynamics.

Uppsala Photon Science Award ceremony

Dr. Max Hantke, Department of Cell and Molecular Biology, Uppsala University: Flash diffractive imaging of biological particles with X-ray lasers.

Abstract: The newly emerging technology of X-ray free-electron lasers (XFELs) has the potential to revolutionise molecular imaging. XFELs generate very intense X-ray pulses and predictions suggest that they may be used for structure determination to atomic resolution even for single molecules. XFELs produce femtosecond pulses that outrun processes of radiation damage and permit the study of structures at room temperature and of structural dynamics. While the first demonstrations of flash X-ray diffractive imaging (FXI) on biological particles were encouraging, they also revealed technical challenges. In my work I exemplified, with heterogeneous cell organelles, how tens of thousands of FXI diffraction patterns can be collected within minutes, analysed in an automatic data processing pipeline, and used to reconstruct projection images at improved resolution. For FXI we inject particles as an aerosol into the XFEL beam. This sample delivery technique allows us to collect data at high hit ratios and with low background. We were able to reduce problems with non-volatile sample contaminants by decreasing aerosol droplet volume by a factor of 1000. We achieved this by adapting an electrospray aerosoliser to our sample injector. Using optical laser scattering imaging we measured positions, sizes, and velocities of individual particles injected into the experimental chamber. XFEL experiments generate large amounts of data at high rates. Preparation, execution, and data analysis of these experiments benefit from specialised software. I developed new open-source software tools that facilitates prediction, online-monitoring, display, and pre-processing of XFEL diffraction data. We hope that this work is a valuable contribution in the quest of transitioning FXI from its first experimental demonstration into a technique that soon reaches its potentials.


Last modified: 2021-02-14