Development of a hard x-ray wavefront sensor for the EuXFEL

Sebastien Berujon (1) , Eric Ziegler (1) , Ruxandra Cojocaru (1) , Thierry Martin (1)

1 ESRF - European Synchrotron Radiation Facility

We present developments on a hard X-ray wavefront sensing instrument for characterizing and monitoring the beam of the European X-ray Free Electron Lasers (EuXFEL). The pulsed nature of the intense X-ray beam delivered by this new class of facility gives rise to strong challenges for the optics and their diagnostic. In the frame of the EUCALL project Work Package 7, we are developing a sensor able to observe the beam in the X-ray energy range [8-40] keV without altering it. The sensor is based on the speckle tracking principle and employs two semi-transparent optics optimized such that their X-ray absorption is reduced. Furthermore, this instrument requires a scattering object with small random features placed in the beam and two cameras to record images of the beam at two different propagation distances. The analysis of the speckle pattern and its distortion from one image to the other allows absolute or differential wavefront recovery from pulse to pulse. Herein, we introduce the stakes and challenges of wavefront sensing at an XFEL source and explain the strategies adopted to fulfil the high requirements set by such a source. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Domaines: Instrumentations et Détecteurs [physics.ins-det]

Sebastien Berujon, Eric Ziegler, Ruxandra Cojocaru, Thierry Martin. Development of a hard x-ray wavefront sensor for the EuXFEL. SPIE Optics + Optoelectronics 2017, Apr 2017, Prague, Czech Republic. pp.102370K, ⟨10.1117/12.2269452⟩. ⟨hal-01815187⟩