Journal Article

Exploring the wavefront of hard X-ray free-electron laser radiation

Bunk, Oliver, Grünert, Jan, Fritz, David M., Samoylova, Liubov, Cammarata, Marco, Rutishauser, Simon, Sinn, Harald, Krzywinski, Jacek, David, Christian

2012

Overview

The high photon flux and femtosecond pulse duration of hard X-ray free-electron lasers have spurred a large variety of novel and fascinating experiments in physical, chemical and biological sciences. Many of these experiments depend fundamentally on a clean, well-defined wavefront. Here we explore the wavefront properties of hard X-ray free-electron laser radiation by means of a grating interferometer, from which we obtain shot-to-shot wavefront information with an excellent angular sensitivity on the order of ten nanoradian. The wavefront distortions introduced by optical elements are observed in-situ and under operational conditions. The source-point position and fluctuations are measured with unprecedented accuracy in longitudinal and lateral direction, both during nominal operation and as the X-ray free-electron laser is driven into saturation. X-ray free-electron lasers offer a wealth of possibilities for future diffraction studies, but variations in successive pulses mean the wavefront is not well defined. Rutishauser et al . use grating interferometry to characterize the wavefronts shot to shot, both in situ and under operating conditions.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/624/1020/1087 / 639/624/1107 / 639/766/400/1106 / Biochemistry, Molecular Biology / Biophysics / Humanities and Social Sciences / Lasers / Life Sciences / multidisciplinary / Optics / Physics / Science / Science (multidisciplinary)