Demonstration of full polarization control of soft X-ray pulses with Apple X undulators at SwissFEL using recoil ion momentum spectroscopy
The ability to freely control the polarization of X-rays enables measurement techniques relying on circular or linear dichroism, which have become indispensable tools for characterizing the properties of chiral molecules or magnetic structures. Therefore, the demand for polarization control in X-ray free-electron lasers is increasing to enable polarization-sensitive dynamical studies on ultrafast time scales. The soft X-ray branch Athos of SwissFEL was designed with the aim of providing freely adjustable and arbitrary polarization by building its undulator solely from modules of the novel Apple X type. In this paper, the magnetic model of the linear inclined and circular Apple X polarization schemes are studied. The polarization is characterized by measuring the angular electron emission distributions of helium for various polarizations using cold target recoil ion momentum spectroscopy. The generation of fully linear polarized light of arbitrary angle, as well as elliptical polarizations of varying degree, are demonstrated.
Authors
- Kirsten Schnorr (ORCID: https://orcid.org/0000-0002-5519-440X)
- Ana-Sofia Morillo-Candas (ORCID: https://orcid.org/0000-0002-6974-1240)
- Jonas Knurr (ORCID: https://orcid.org/0000-0002-9455-0702)
- Sven Augustin (ORCID: https://orcid.org/0000-0003-1283-331X)
- Eduard Prat (ORCID: https://orcid.org/0000-0002-7065-7417)
- Iwona Swiderska (ORCID: https://orcid.org/0000-0002-6863-4291)
- Antoine Sarracini (ORCID: https://orcid.org/0000-0003-2246-815X)
- Nicholas Sammut (ORCID: https://orcid.org/0000-0001-7679-604X)
- Gregor Knopp (ORCID: https://orcid.org/0000-0002-0786-3402)
- Christoph Bostedt (ORCID: https://orcid.org/0000-0001-8169-8639)
- Marco Calvi (ORCID: https://orcid.org/0000-0002-2502-942X)
- Christoph Kittel (ORCID: https://orcid.org/0000-0001-5527-1009)
- Eugenio Ferrari (ORCID: https://orcid.org/0000-0002-1082-5984)
- André Al Haddad (ORCID: https://orcid.org/0000-0002-2575-8200)
- Ningchen Yang (ORCID: https://orcid.org/0009-0003-8374-6683)
- Thomas Schmidt (ORCID: https://orcid.org/0000-0002-3205-2724)
Institutions
- University of Malta (MT)
- Deutsches Elektronen-Synchrotron DESY (DE)
- Paul Scherrer Institute (CH)
- École Polytechnique Fédérale de Lausanne (CH)
Publication Details
- Journal
- Journal of Synchrotron Radiation
- Published
- 2024-08-09
- DOI
- https://doi.org/10.1107/s1600577524006325
- Citations
- 1
- Primary Topic
- Advanced X-ray Imaging Techniques
- Type
- article
- Field-Weighted Citation Impact
- 0.61
Funders
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- H2020 Marie Skłodowska-Curie Actions