Investigations of the effect of optical imperfections on partially coherent X-ray beam by combining optical simulations with wavefront sensing experiments

QUICK INFORMATION
Type
PhD Defense
Start Date
01-02-2021 13:00
End Date
01-02-2021 15:00
Location
Auditorium, Central Building, Zoom
Speaker's name
Rafael CELESTRE
Speaker's institute
Université Grenoble Alpes
Contact name
Manuel SANCHEZ DEL RIO
Host name
Raymond BARRETT
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Soutenance de thèse de Rafael CELESTRE

    Investigations of the effect of optical imperfections on partially coherent X-ray beam by combining optical simulations with wavefront sensing experiments

 

Titre français : Étude de l'effet des imperfections optiques aux faisceaux de rayons X partiellement cohérents en combinant les simulations optiques avec les mesures du front d'onde
Ecole Doctorale : Physique
Spécialité : Physique de la Matière Condensée et du Rayonnement
Etablissement : Université Grenoble Alpes
Unité de recherche : European Synchrotron Radiation Facility



Cette soutenance aura lieu Lundi 01 Février 2021 à 13h00

Adresse de la soutenance : ESRF - the European Synchrotron 71 Avenue des Martyrs, 38000 Grenoble - salle Auditorium

Résumé de la thèse en anglais:  

In physical optics, weakly focusing elements are usually simulated as a single thin element. While a single X-ray lens at typical operation conditions can often be represented in this way, simulating a full lens stack with a similar approach lacks versatility. This work proposes decomposing a CRL into its lenslets separated by a free-space propagation, similar to the multi-slicing techniques already used for optical simulations. Attention is given to modelling the single lens element by adding additional degrees of freedom allowing the modelling of typical misalignments and fabrication errors. Orthonormal polynomials for optical aberrations as well as metrology data obtained with X-ray speckle vector tracking (XSVT) are also used to obtain realistic simulation results, which are presented in several coherent- and partially coherent simulations throughout this work. Implementing a model of X-ray lenses using metrology data allows extraction of the accumulated figure errors and enables the calculation of phase corrections. Finally, this thesis presents a methodology for calculating the profile of refractive correctors, which is applied to produce phase plates ablated from diamond. Early experimental results show an improvement on the beam profile. This project addressed important aspects of the ESRF-EBS X-ray optics R&D programme as laid out in the strategic upgrade plan.

13:00 - 15:00  Webinar and questions

You can join the thesis defense online here
https://esrf.zoom.us/j/97104640008?pwd=aExEK3VyWVUxVXFBV3JSRU9vSlhSdz09

Meeting ID: 971 0464 0008
Passcode: 443152

(Scientific contacts: Manuel Sanchez del Rio & Raymond Barrett)

Visitors from off-site please contact Manuel SANCHEZ DEL RIO tel +33 (0)4 to arrange for a gate pass.
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