Overcoming the challenges of high-energy X-ray ptychography

Julio Cesar da Silva (1) , Cyril Guilloud (2) , Olivier Hignette (2) , Christophe Jarnias (2) , Cyril Ponchut (2) , Marie Ruat (2) , Jean-Claude Labiche (2) , Alexandra Pacureanu (2) , Yang Yang (2) , Murielle Salomé (2) , Sylvain Bohic (2) , Peter Cloetens (2)

1 NEEL - MRS - Matériaux, Rayonnements, Structure
2 ESRF - European Synchrotron Radiation Facility

X-ray ptychography is a coherent diffraction imaging technique with a high resolving power and excellent quantitative capabilities. Although very popular in synchrotron facilities nowadays, its implementation with X-ray energies above 15 keV is very rare due to the challenges imposed by the high energies. Here, the implementation of high-energy X-ray ptychography at 17 and 33.6 keV is demonstrated and solutions to overcome the important challenges are provided. Among the particular aspects addressed are the use of an efficient high-energy detector, a long synchrotron beamline for the high degree of spatial coherence, a beam with 1% monochromaticity providing high flux, and efficient multilayer coated Kirkpatrick-Baez X-ray optics to shape the beam. The constraints imposed by the large energy bandwidth are carefully analyzed, as well as the requirements to sample correctly the high-energy diffraction patterns with small speckle size. In this context, optimized scanning trajectories allow the total acquisition time to be reduced by up to 35%. The paper explores these innovative solutions at the ID16A nano-imaging beamline by ptychographic imaging of a 200 nm-thick gold lithography sample.

Mots clés: X-ray ptychography; nano-imaging; KB mirrors; coherence; high-energy X-rays; coherent X-ray diffraction

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique [physics]; Optique / photonique; Traitement du signal et de l'image [eess.SP]

Julio Cesar da Silva, Cyril Guilloud, Olivier Hignette, Christophe Jarnias, Cyril Ponchut, et al.. Overcoming the challenges of high-energy X-ray ptychography. Journal of Synchrotron Radiation, 2019, 26 (5), pp.1751-1762. ⟨10.1107/S1600577519006301⟩. ⟨hal-02612387⟩