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A: Fachverband Atomphysik
A 22: Atomic Clusters II (joint session A/MO)
A 22.7: Vortrag
Dienstag, 6. März 2018, 15:30–15:45, K 2.016
Optical focusing of isolated particles for diffractive imaging experiments — •Salah Awel1,4, Daniel Horke1,4, Rick Kirian2, Xiaoyan Sun1, Andrei Rode3, Jochen Küpper1,4,5, and Henry Chapman1,4,5 — 1Center for Free-Electron Laser Science, DESY, Hamburg, Germany — 2Arizona State University, Tempe, AZ, USA — 3Laser Physics Centre, Australian National University, Canberra, Australia — 4Center for Ultrafast Imaging, Universität Hamburg, Germany — 5Department of Physics, Universität Hamburg, Germany
Single-particle imaging (SPI) is emerging as a new techniques at x-ray free-electron lasers (XFELs) that consists of directing a stream of randomly oriented bioparticles across the focus of the XFEL beam aiming to construct high-resolution 3D structure from diffraction patterns of multiple identical particles. Presently, the difficulty of efficiently delivering isolated bioparticles to the sub-micrometer x-ray focus is the limiting factor in the development of SPI. In order to mitigate this problem, we have developed a technique for guiding aerosolized nanoparticles to the x-ray focus using spatially shaped optical laser beam [1]. Our current experiments aim at transversely confining streams of aerosolized particles as they exit an aerosol injector with a counter-propagating “hollow-core” quasi-Bessel beam. Through radiation pressure and thermal (photophoretic) forces that arise from the interaction of the particle with the surrounding gas molecules, the particles confine within the low-intensity core of the laser beam [2].
[1] Eckerskorn et al., Opt. Exp. 21, 30492-30499 (2013).
[2] Eckerskorn et al., Phys. Rev. Applied 4, 064001 (2015).