ª PHOTON SCIENCE Deutsches Elektronen-Synchrotron DESY A Research Centre of the Helmholtz Association 2020ª Highlights and Annual Report The Helmholtz Association is a community of 19 scientific-technical and biological-medical research centres. These centres have been commissioned with pursuing long-term research goals on behalf of the state and society. The Association strives to gain insights and knowl edge PHOTON SCIENCE AT DESY 2020 so that it can help to preserve and improve the foundations of human life. It does this by identifying and working on the grand challenges faced by society, science and industry. Helmholtz Centres perform top-class research in strategic programmes in six core fields: Energy, Earth & Environment, Health, Aeronautics, Space and Transport, Matter, and Key Technologies. www.helmholtz.de Deutsches Elektronen-Synchrotron DESY A Research Centre of the Helmholtz Association Umschlag_PhotonScience2020_ehs.indd 1 04.01.21 13:15 Imprint Publishing and Contact: Online version: Deutsches Elektronen-Synchrotron DESY photon-science.desy.de/annual_report A Research Centre of the Helmholtz Association Cover Realisation: Traditionally, both silicon (Si) and silicon-germanium (SiGe) have a cubic crystal Hamburg location: Wiebke Laasch, Daniela Unger structure. Silicon is extremely successful in the electronics industry and has provided the Notkestr. 85, 22607 Hamburg, Germany basis for electronic devices like personal computers and smartphones. However, cubic Tel.: +49 40 8998-0, Fax: +49 40 8998-3282 Editing: silicon is not able to emit light, meaning it cannot be used for fabricating light emitting [email protected] Sadia Bari, Lars Bocklage, Günter Brenner, Thomas Keller, diodes or lasers for optical communication. Si and SiGe with a hexagonal crystal Wiebke Laasch, Britta Niemann, Leonard Müller, Nele Müller, structure, known as hex-SiGe was fabricated. Its hexagonal crystal structure is the key Zeuthen location: Christoph Schlüter, Sang-Kil Son, Sebastian Trippel, to transforming SiGe into a very efficient light-emitting semiconductor for germanium Platanenallee 6, 15738 Zeuthen, Germany Daniela Unger, Thomas White compositions above 65%. Taking advantage of synchrotron radiation, an international Tel.: +49 33762 7-70, Fax: +49 33762 7-7413 team from the Netherlands, Germany, Austria and Canada measured the crystalline [email protected] Layout: Sabine Kuhls-Dawideit, Büro für Grafik und Design, properties of the hex-SiGe polytypes for the first time. Halstenbek Photon Science at DESY The cover picture shows high resolution X-ray diffraction measurements performed Tel.: +49 40 8998-2304, Fax: +49 40 8998-4475 Printing and image processing: EHS Druck GmbH, Schenefeld at PETRA III beamline P08. The position of the ( 018) Bragg reflection (in red) shifts as [email protected] a function of different Ge concentrations from 61% to 100% from left to right photon-science.desy.de Copy deadline: December 2020 (details see page 52/53). www.desy.de (Reprint by permission from Springer Nature: Nature ‘Direct-bandgap emission from hexagonal Reproduction including extracts is permitted subject Ge and SiGe alloys’, Fadaly, E. M. T. et al., Copyright 2020) ISBN 978-3-945931-34-9 to crediting the source. Umschlag_PhotonScience2020_ehs.indd 2 04.01.21 13:15 PHOTON SCIENCE 2020ª Highlights and Annual Report Inhalt_PhotonScience2020_ehs.indd 1 04.01.21 13:05 2 | Contents Inhalt_PhotonScience2020_ehs.indd 2 04.01.21 13:05 Contents º Introduction 6 º News and Events 8 º Corona Special 16 º Science Highlights 22 • Life Sciences 22 • Nano and materials science 34 • Electronic and magnetic structure 46 • Structure and structural dynamics 54 • Quantum optics, atomic and molecular dynamics 66 • Science of laser and X-ray sources - methods and developments 74 º Light Sources 84 º Campus and Collaborations 96 º Facts and Numbers 114 Publications The list of publications based on work done at DESY Photon Science is accessible online: http://photon-science.desy.de/research/publications/list_of_publications/index_eng.html DESY tries to keep this list as complete and as updated as possible, and relies on the support by all users, who are kindly requested to register their publications via DOOR (door.desy.de). Contents | 3 Inhalt_PhotonScience2020_ehs.indd 3 04.01.21 13:05 The year 2020 at DESY Chairman’s foreword 2020 was a truly unusual year for the global society. In March, These measures were critical with respect to the user opera- the coronavirus brought our accustomed everyday life to a tion of our large-scale research facilities PETRA III and standstill and mercilessly exposed the vulnerability of our FLASH. Especially the unique analysis capabilities at modern society to such crisis. We will have to put many of PETRA III have proven to be most important for the fight our habits, that have finally proven to be unsustainable, to test against the SARS-CoV-2 coronavirus. We have to ensure that and find new ways forward. We have already learned a great these technologies will be even more targeted to molecular deal in recent months, most importantly that our society can drug research and even more crisis-proven in the future. To rely on science and on decision makers who listen to scientists. this end, we have drawn up a major proposal for the estab- lishment of a ‘National Analysis Center for Molecular Infection We at DESY reacted quickly and very cautiously to the pan- Research’ in which new digital and technical concepts like demic and moved the research centre into a safe mode that artificial intelligence, remote control and robotics are to be kept the laboratories and our research largely in operation incorporated. ‘Digital DESY’ has become a new building while protecting all staff from infection chains as efficiently as block in our DESY strategy, in response to the challenges of possible. the current pandemic and of future crisis situations. We will Part of the DESY staff in Hamburg holds the DESY-60 logo. 4 | Introduction Inhalt_PhotonScience2020_ehs.indd 4 04.01.21 13:05 Senate reception for the 60th DESY anniversary in Hamburg: with forward-looking cutting-edge research into the new decade. also pay even greater attention to sustainable concepts in all dark-matter particles BabyIAXO, as well as the ‘Cherenkov our activities and future projects. Telescope Array’ CTA and Data Centre will be implemented. Promoting our top scientists and our young talents is an DESY is well on its way into this future. The priority project is essential component of the DESY strategy. The new Helm- PETRA IV which has now entered the technical design phase. holtz graduate school DASHH has been well-established in We are very pleased that with Riccardo Bartolini, who joined 2020. The aim here is to educate the future generation of data DESY in April 2020, we have been able to attract an interna- scientists who can efficiently analyse measured data by tionally renowned accelerator physicist for this future project. using, e.g. AI or machine learning. This year, we have imple- In the next few years, the task will be to prepare all the logis- mented the COAST programme which will assist our post- tical and personnel prerequisites for the upgrade of the syn- docs to shape their individual career pathways. Our HR chrotron radiation source PETRA III and to raise the neces- department has done a remarkable job here. Over the coming sary financial resources for this complex project. Nearly all months, we must and will develop concepts to offer our top areas of DESY will be involved here in the upcoming decade. academic performers new career paths within the research centre. In 2020 we have made good progress in various projects, as in the development of the CMWS, the ‘Centre for Molecular DESY has celebrated its 60th anniversary in the Hamburg Water Science’, the commissioning of the Detector Assembly City Hall at the beginning of the year. Many congratulations Facility and the construction of the ‘Bahrenfeld Start-Up also came from the global science community and have hon- Labs’ as well as in the CXNS, the ‘Centre for X-ray and Nano oured DESY as a world-leading centre in the exploration of Science’ which will open next year. An active innovation matter. We are well-prepared for the coming decades to con- culture, which interlinks basic research and fast transfer of tinue the legacy of DESY. innovative concepts to the market will remain an integral part of DESY’s future strategy. Even in these challenging times, the extraordinary commit- ment of the staff and all users and partners, national and In the coming years, further projects are on the agenda: international, made research possible at DESY – I would like Major new construction measures include the DESYUM visi- to thank all who contributed to the joint efforts! tor centre, the building for the accelerator division, the TECH- NICUM for technical groups, the DESY Innovation Factory and the ‘Wolfgang Pauli Centre’ WPC for theoretical physics. Important research and upgrade projects such as of the free-electron laser FLASH to FLASH2020+, the KALDERA- ATHENA project for future accelerator technologies, the ‘Any Helmut Dosch Light Particle Search’ ALPS II, and the telescope in search of Chairman of the DESY Board of Directors Introduction | 5 Inhalt_PhotonScience2020_ehs.indd 5 04.01.21 13:05 Photon Science at DESY Introduction The DESY site in Hamburg with the curved PETRA III experimental hall ‘Max von Laue’ in the middle and the ‘Ada Yonath’ as well as the ‘Paul Peter Ewald’ halls to the left and right, respectively. The FLASH experimental halls ‘Albert Einstein’ and ‘Kai Siegbahn’ are located between the two PETRA III halls on the right side (August 2020). Dear Colleagues and Friends of DESY Photon Science, restrictions of user groups, DESY decided to shut down the operation of its user facilties PETRA III and FLASH by mid The year 2020 started very promising with an extremely of March.