Open AccessHartmann wavefront sensors and their application at FLASH
Author(s) -
Keitel Barbara,
Plönjes Elke,
Kreis Svea,
Kuhlmann Marion,
Tiedtke Kai,
Mey Tobias,
Schäfer Bernd,
Mann Klaus
Publication year - 2016
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577515020354
Subject(s) - wavefront , optics , wavefront sensor , physics , beamline , flash (photography) , usable , laser , adaptive optics , deformable mirror , free electron laser , beam (structure) , computer science , world wide web
Different types of Hartmann wavefront sensors are presented which are usable for a variety of applications in the soft X‐ray spectral region at FLASH, the free‐electron laser (FEL) in Hamburg. As a typical application, online measurements of photon beam parameters during mirror alignment are reported on. A compact Hartmann sensor, operating in the wavelength range from 4 to 38 nm, was used to determine the wavefront quality as well as aberrations of individual FEL pulses during the alignment procedure. Beam characterization and alignment of the focusing optics of the FLASH beamline BL3 were performed with λ 13.5 nm /116 accuracy for wavefront r.m.s. ( w rms ) repeatability, resulting in a reduction of w rms by 33% during alignment.