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ELBE is a compact, accelerator-driven photon and particle source. The variety of secondary radiation being offered extends from high-energy gamma rays to infrared and THz radiation as well as from neutrons to positrons and electrons. Since 2001 ELBE is operated as a user facility, providing more than 5500 hours of beamtime with an efficiency of more than 90% each year. The electron accelerator is based on four superconducting 9-cell TESLA cavities that are driven in CW operation to accelerate an average current of 1 mA up to beam energies of 40 MeV. In addition an upgraded version of a superconducting radio-frequency (SRF) photoinjector was brought into operation in 2014. After a period of commissioning, a gradual transfer to routine operation took place in 2017, so that now more than 1800h of user beam are generated by this unique CW electron source every year. The talk will summarize our experiences of operating all our SRF cavities over two decades in CW. In detail, this includes the cavity performance and attempts to improve it, as well as investigations on their limitations. Additionally, we will discuss several issues that are related to the high average RF as well as beam power and we will present appropriate measures to protect the machine. In this regard we will also introduce a resonant ring for RF component tests at CW power levels up to 100 kW. Regarding the SRF gun, the main emphasis lies in seamlessly integrating a normal-conducting photocathode into the SRF cavity, alongside addressing associated intricacies like dark current, multipacting, and contamination of the resonator.

This data was taken at DSEY (04-08.12.2023) using a climate chamber. Multiple temperature and humidity sensors were put into the climate chamber. Due to problems with the ChimeraTK server not all data was collected by a single ChimeraTK server, but the sensors were grouped and read by different 1-wire servers (`1-wire_1`, `1-wire_2`, `1-wire_3`, `1-wire_4`, `1-wire_5`). Each sensor identification is listed in the owfs.xlmap file. First sensor in owfs.xlmap corresponds e.g. to DS18B20/0. Data is available as HDF5 and ROOT file. In addition the MRF timing system was running. Two EVRs (EVR2, EVR3) were connected via long fibers (100m) to the EVM. The fibers routed through the climate chamber, such that most of the fiber was inside the chamber. A Rhode&Schwartz oscilloscope was used to measure the delay of the timing output signals with respect to a third EVR (EVR1), that was connected via a short cable outside the climate chamber. That data is included in timing-data.root, which includes: Delay of EVR2 with respect to EVR1 -> Delay_C1C2 Delay of EVR3 with respect to EVR1 -> Delay_C1C3 Delay compensation (actual, correction) for each EVR The intended measurement, was to use active delay compensation for EVR2 and deactivated delay compensation for EVR3. However, the measurement was spoiled by periodic delay shifts in case of EVR2. On 07.12. 10:20 the delay compensation was also activated for EVR3. For technical reasons not all timing related data is included in rs-data.root. The delay compensation data (actual, correction) should be taken from the aggregated raw data. It includes basically all data (temperature, humidity, oscilloscope data), but in the beginning the actual delay measurement was missing (which should be taken from timing-data.root). Selected data periods are listed in the file data.ods. Some analysis results are already included here for convenience

Running a C.W. electron accelerator as a user facility for more than two decades necessitates upgrades or even complete redesign of subsystems at some point. At ELBE, the outdated timing system needed a replacement due to obsolete components and functional limitations. Starting in 2019, with Cosylab as contractor and using hardware by Micro Research Finland, the new timing system has been developed and tested and is about to become operational. Besides the ability to generate a broader variety of beam patterns from single pulse mode to 26 MHz C.W. beams for the two electron sources, one of the benefits of the new system is improved machine safety. The ELBE control systems is mainly based on PLCs and industrial SCADA tools. This contribution depicts how the timing system implementation to the existing machine entailed extensions and modifications of the ELBE machine protection system, i.e. a new core MPS PLC, and how they are being realized.

The Dresden Advanced Light Infrastructure is a future infrastructure under consideration at the Helmholtz-Zentrum Dresden-Rossendorf. In the current conceptional design phase, we are surveying different control system options. To benefit as much as possible from community experiences with different control systems, in 2023 a survey was conducted and participants from accelerator and light source facilities world-wide were invited. The results of that survey are presented and conclusions for our center are drawn.

Running a C.W. electron accelerator as a user facility for more than two decades necessitates upgrades or even complete redesign of subsystems at some point. At ELBE, the outdated timing system needed a replacement due to obsolete components and functional limitations. Starting in 2019, with Cosylab as contractor and using hardware by Micro Research Finland, the new timing system has been developed and tested and is about to become operational. Besides the ability to generate a broader variety of beam patterns from single pulse mode to 26 MHz C.W. beams for the two electron sources, one of the benefits of the new system is improved machine safety. The ELBE control systems is mainly based on PLCs and industrial SCADA tools. This contribution depicts how the timing system implementation to the existing machine entailed extensions and modifications of the ELBE machine protection system, i.e. a new core MPS PLC, and how they are being realized.

Modern Big physics experiments call for optimizations of machines in various aspects. Integration of an advanced control system is one of them, and timing system as controls’ backbone is most often required to be upgraded significantly or even designed and implemented anew. The complexity of experiments at HZDR ELBE and the range of varieties of its instruments and subsystems is combined with top-notch performance requirements. These, coupled with hardware obsolescence, dictate an implementation of an advanced timing system, surpassing a system, that was designed initially. The new timing system must be compatible with all existing timing triggering patterns and must provide configuration option for new features. It is designed to generate trigger patterns for shot on demand to 26 MHz cw which requires a universal and complex implementation of the pattern composition and validity checks. The design of this timing solution further demands the adaptation and the modification of the event-based timing system built on MRF HW. As a result, we realized the new Control Software with an extended range of functionalities. While maintaining the common functionality we made it suitable for the most demanding experiments today.

The Dresden Advanced Light Infrastructure is a future infrastructure under consideration at the Helmholtz-Zentrum Dresden-Rossendorf. In the current conceptional design phase, we are surveying different control system options. To benefit as much as possible from community experiences with different control systems, in 2023 a survey was conducted and participants from accelerator and light source facilities world-wide were invited. The results of that survey are presented and conclusions for our center are drawn.

At the electron accelerator for beams with high brilliance and low emittance (ELBE), the second version of a superconducting radio-frequency (SRF) photoinjector was brought into operation in 2014. After a period of commissioning, a gradual transfer to routine operation took place in 2017, so that now more than 1800h of user beam are generated every year. Since the commission, a total of 24 cathodes (2 Cu, 12 Mg, 10 Cs2Te) have been used, without observing serious cavity degradation. The contribution summarized commissioning and operational experience of the last years, with special emphasis on SRF properties but also on specialties such as dark current and multipacting that are directly linked to the integration of a normal conducting cathode into the SRF cavity.

The representation of the complex behavior of cohesive sediments in numerical models is a major challenge. To tackle this situation and deepen the understanding of estuarine sediment transport in general, the joint project ELMOD is conducted. Involved partners are the Federal Waterways Engineering and Research Institute (BAW, model application), the University of the Bundeswehr Munich (UniBW, development of model approaches) and the Hamburg University of Technology (TUHH, field measurements and laboratory investigations). This contribution outlines the conception of the first ship-based measurement campaign in the research project ELMOD which was conducted in the port area of Hamburg. It puts a focus on the in-situ measurements of vertical density- and SSC-profiles with different methods. Additionally, the agreement of the in-situ measured density profiles with the vertical density distribution of sediment cores collected during the same campaign is checked. The utilized devices and techniques deliver very consistent results. The bed-density profiles and especially their gradient are in good agreement for the subsamples of the extracted cores, Admodus USP pro, Rheotune and sediment echosounder, which shows that the extracted sediment cores reflect the natural density profiles to a high degree. The slightly different elevations of the associated densities are seen to be due to small changes in Ship positions. Hach Solitax sc and peristaltic pump (+vacuum filtration) deliver comparable SSC-values in the water column. In the relatively thin bottom layer with rapidly rising sediment concentrations both techniques reach their limits., Federal Ministry of Education and Research (BMBF)

Between 2013 and 2018, striking hydrological and morphological changes were observed in the Tidal Elbe, in particular an unusually strong increase in tidal range, turbidity and sedimentation rates. The latter led to increased maintenance dredging, which, however, represents a major economic and ecological burden. Reasons for the described changes are seen in morphological changes in the mouth of the estuary, persistently low headwater discharges and insufficiently adapted sediment management (Weilbeer et al. 2021). The numerical models currently used cannot adequately represent these developments. In particular, the complex behaviour of cohesive sediments in the heavily anthropogenically influenced river sections such as the port of Hamburg poses a major challenge. The joint project ELMOD is conducted to improve the predictive capability of numerical models and to improve the understanding of estuarine sediment transport in general. For this purpose, the changes observed in the Tidal Elbe in the period 2013-2018 are analysed by means of hindcast studies and the model approaches used are extended on the basis of natural measurements and laboratory investigations. The partners involved are the Federal Waterways Engineering and Research Institute (BAW, model application), the University of the Bundeswehr Munich (UniBW, development of model approaches) and the Hamburg University of Technology (TUHH, field measurements and laboratory investigations)., Federal Ministry of Education and Research (BMBF)

The coherent infrared and THz sources driven by the superconducting electron accelerator ELBE are described. The present status of the facility is summarized and a few scientific highlights are mentioned. Finally plans for a successor facility (Dresden Advanced Light Infrastructure, DALI) are outlined along with the most important scientific and technological challenges.

Für den Betrieb des Elektronen-Linearbeschleunigers am ELBE - Zentrum für Hochleistungsstrahlenquellen arbeiten wir im Bereich SCADA-System seit 2019 mit Kontron AIS GmbH im Rahmen eines Dienstleistungsvertrags zusammen. Wir stellen in der Präsentation den Beschleuniger vor, beschreiben die einzelnen Support- und Projektthemen und die damit verbundenen Vorteile für Betriebssicherheit und Nutzerfreundlichkeit und Wieterentwicklung unseres WinCC Leitsystems.

At the electron accelerator for beams with high brilliance and low emittance (ELBE), the second version of a superconducting radio-frequency (SRF) photoinjector was brought into operation in 2014. After a period of commissioning, a gradual transfer to routine operation took place in 2017, so that now more than 1800h of user beam are generated every year. Since the commission, a total of 24 cathodes (2 Cu, 12 Mg, 10 Cs2Te) have been used, without observing serious cavity degradation. The contribution summarizes commissioning and operational experience of the last 8 years of gun operation, with special emphasis on SRF properties but also on specialties such as dark current and multipacting that are directly linked to the integration of a normal conducting cathode into the SRF cavity.

Excess nitrogen (N) from agricultural sources is a major contributor to the water pollution of rivers in Europe. Floodplains are of tremendous importance as they can permanently remove nitrate (NO3) from the environment by releasing reactive N to the atmosphere in its gaseous forms (N2O, N2) during denitrification. However, the quantitative assessment of this ecosystem function is still challenging, particularly on the national level. In this study, we modeled the potential of NO3-N removal through microbial denitrification in soils of the active floodplains of the river Elbe and river Rhine in Germany. We combined laboratory measurements of soil denitrification potentials with straightforward modelling data, covering the average inundation duration from six study areas, to improve an existing Germany-wide proxy-based approach (PBAe) on NO3-N retention potential. The PBAe estimates this potential to be 30–150 kg NO3-N ha−1 yr−1. However, with soil pH and Floodplain Status Category identified as essential parameters for the proxies, the improved PBA (PBAi) yields a removal potential of 5–480 kg N ha−1 yr−1. To account for these parameters, we applied scaling factors using a bonus-malus system with a base value of 10–120 N ha−1 yr−1. Upscaling the determined proxies of the PBAi to the entire active floodplains of the river Elbe and river Rhine results in similarly high NO3-N retention sums of ~7000 t yr−1 in spite of very different retention area sizes, strengthening the argument for area availability as the primary objective of restoration efforts. Although PBAs are always subject to uncertainty, the PBAi enables a more differentiated spatial quantification of denitrification because local key controlling parameters are included. Hence, the PBAi is an innovative and robust approach to quantify denitrification in floodplain soils, supporting a better assessment

Ein durch den Lausitzer Braunkohlentagebau Welzow-Süd erschlossener, etwa 250 x 800 m ausgedehnter Aufschluss in den Sedimenten des sogenannten Senftenberger Elbelaufes bzw. der obermiozänen Rauno-Formation bot Anlass für umfangreiche Geländedokumentationen und eine Neubetrachtung der Thematik dieser Elbeablagerungen. Anhand verschiedener sedimentologischer und chemisch-mineralogischer Dokumentationen und Analyseverfahren wurden sowohl dieser Aufschluss als auch acht weitere Lokalitäten untersucht. Im Fokus der Auswertung standen zum einen eine detaillierte Milieu- und Geneseinterpretation der fluviatilen Sedimente im Tagebau Welzow-Süd, zum anderen die Frage nach der stratigraphischen Korrelation der durch quartäre Erosion isolierten Aufschlüsse. Das Ergebnis zeigt, dass die Senftenberger Elbe mit der Hebung des Oberlausitz-Plateaus als verflochtener Fluss vom späteren Elbtal aus durch die Lausitz Richtung Paläo-Nordsee strömte. Eine räumlich-zeitliche Korrelation der einzelnen Aufschlüsse und eine konkrete Flussverlaufsrekonstruktion sind nicht möglich. Auch die bisher etablierte Unterteilung der Senftenberger Elbe in drei zeitliche Abschnitte ist nicht belastbar. Es ist von einer variablen Flussverlaufsentwicklung mit zuströmenden Nebenflüssen auszugehen. Die biostratigraphischen Arbeiten verschiedener Autoren belegen ein obermiozänes bis pliozänes Alter.:Zusammenfassung Abstract Abbildungsverzeichnis Tabellenverzeichnis Anlagenverzeichnis Abkürzungsverzeichnis 1 Einleitung 2 Methodik 2.1 Geländeuntersuchungen 2.2 Laboruntersuchungen 2.3 Untersuchungen an Konkretionen 3 Regionale Geologie 4 Stand der Wissenschaft 5 Ergebnisse 5.1 Tagebau Auerhahn 5.2 Ehemalige Kiesgrube bei Brauna 5.3 Tagebau Cunnersdorf 5.4 Tagebau Laußnitz I 5.5 Tagebau bei Lauta 5.6 Tagebau Nochten 5.7 Tagebau Sallgast 5.8 Tagebau Welzow-Süd 5.9 Tagebau Wiesa 5.10 Korngrößenparameter 5.11 Kornform 5.12 Modalbestand der Gerölle 6,3 - 10 mm 5.13 Hellglimmer 5.14 Schwerminerale 5.15 Paläoströmung, The lignite opencast mine Welzow-Süd, Lusatia, provided an excellent outcrop of the fluvial sediments of the so-called Senftenberger Elbelauf (Rauno Formation, Upper Miocene) with a dimension of 250 to 800 m, that delivered new insights into the history of this former river. This location and additionally eight further outcrops were investigated using different sedimentological and chemical-mineralogical analyses. A detailed interpretation of the environment and genesis of the fluvial sediments in Welzow-Süd is given and the results for all investigated outcrops are related. After the uplift of the Upper Lusatian Plateau, the Senftenberger Elbe developed to a braided river, that ran through the Lusatian region towards the paleo North Sea. A precise reconstruction of the river channels way is not possible. A reliable spatiotemporal correlation of the single outcrops can’t be given. Furthermore, the so far established division of this river into three parts of different ages must be rejected. A complex river system with feeder channels and variable flow pattern is more probable. The biostratigraphic results of different authors prove an Upper Miocene to Pliocene age.:Zusammenfassung Abstract Abbildungsverzeichnis Tabellenverzeichnis Anlagenverzeichnis Abkürzungsverzeichnis 1 Einleitung 2 Methodik 2.1 Geländeuntersuchungen 2.2 Laboruntersuchungen 2.3 Untersuchungen an Konkretionen 3 Regionale Geologie 4 Stand der Wissenschaft 5 Ergebnisse 5.1 Tagebau Auerhahn 5.2 Ehemalige Kiesgrube bei Brauna 5.3 Tagebau Cunnersdorf 5.4 Tagebau Laußnitz I 5.5 Tagebau bei Lauta 5.6 Tagebau Nochten 5.7 Tagebau Sallgast 5.8 Tagebau Welzow-Süd 5.9 Tagebau Wiesa 5.10 Korngrößenparameter 5.11 Kornform 5.12 Modalbestand der Gerölle 6,3 - 10 mm 5.13 Hellglimmer 5.14 Schwerminerale 5.15 Paläoströmung 6 Interpretation und Diskussion 7 Zusammenfassung und Ausblick 8 Danksagung 9 Literaturverzeichnis

At the electron accelerator for beams with high bril-liance and low emittance (ELBE), the second version of a superconducting radio-frequency (SRF) pho-toinjector was brought into operation in 2014. After a period of commissioning, a gradual transfer to routine operation took place in 2017 and 2018, so that now more than 3400h of user beam have already been gen-erated since 2019. During this time, a total of 20 cath-odes (2 Cu, 12 Mg, 6 Cs2Te) were used, but no serious cavity degradation was observed. In this paper, we summarize the operational experience of the last 6 years of SRF gun operation, with special emphasis on main RF properties of the gun cavity.

The bunch arrival time monitor (BAM) at the radiation source ELBE has been upgraded twofold. In order to achieve a higher precision a new frontend has been designed, based on a development by DESY, that uses state of the art 50 GHz electro-optical modulators (EOMs). The frontend allows for thermal control of critical components and monitoring of system parameters. The modulated EOM signals and monitoring data are distributed to a new readout electronic. The new MicroTCA-based receiveris based on a dedicated FMC card developed at DESY that is installed on an FMC25 carrier board. The arrival time is calculated on a FPGA with low latency and can be used for machine diagnostic. The code has been adapted to enable the processing of a data stream of the continuous train of electron bunches, allowing for the implementation of a cw beam based feedback in a next step. The contribution will describe the BAM setup as well as the performance measured at the ELBE accelerator.

We present the deliverables achieved for a summarization of the prototyped remote data analysis services and the derived outcomes that have been realised in the process at each ExPaNDS partner facility to align with the PanOSC project and to proceed towards onboarding services into the EOSC portal. The work represents the achievement of deliverable D4.4 of the Horizon 2020 ExPaNDS project. ExPaNDS is the EU Project: European Open Science Cloud Photon and Neutron Data Services

The ELBE accelerator at Helmholtz-Zentrum Dresden-Rossendorf has been commissioned in 2001 using klystron power amplifiers. In the course of a major machine upgrade in 2012, solid state power amplifiers have been installed to drive the superconducting cavities and to increase the maximum beam current to 1.6 mA. The talk will introduce the high power radio frequency system of the continuous wave (CW) accelerator ELBE, wrap-up the operational experience and will give an outlook to the potential successor of machine called DALI.

ELBE is a compact, accelerator-driven photon and particle source. The variety of secondary radiation being offered extends from high-energy gamma rays to infrared and THz radiation as well as from neutrons to positrons and electrons. Since 2001 ELBE is operated as a user facility, providing more than 5500 hours of beamtime with an efficiency of more than 90% each year. The electron accelerator is based on four superconducting 9-cell TESLA cavities that are driven in CW operation to accelerate an average current of 1 mA up to beam energies of 40 MeV. The the talk will summarize our experiences of operating TESLA cavities over two decades in CW. In detail, this includes the cavity performance and attempts to improve it, as well as investigations on their limitations. Additionally, we will discuss several issues that are related to the high average RF as well as beam power and we will present appropriate measures to protect the machine. In this regard we will also report on long-term experiences with our 10kW 1.3 GHz solid state power amplifiers and introduce a resonant ring for RF component tests at CW power levels up to 100 kW.

Durch eindrückliche Erfahrungen und Begegnungen mit anderen Sprachen und Kulturen erlebte die Autorin selbst, was bereits von Goethe (1833) sagte: «Wer fremde Sprachen nicht kennt, weiss nichts von seiner eigenen» (S. 26). Ihr Verständnis der eigenen sprachlichen und kulturellen Herkunft, ihre Offenheit und ihr Interesse gegenüber Fremdsprachen wuchsen dank dieser Erlebnisse. Deshalb wurde es zu ihrem Anliegen, diese positive Einstellung gegenüber Sprachen und Kulturen im Unterricht zu fördern. Als geeignete Methode stiess sie auf die Förderung der Sprachbewusstheit, welche ein Teil der Mehrsprachigkeitsdidaktik ist. Weil deren Einbettung im Unterricht für Lehrpersonen eine Herausforderung darstellt, wollte sie an dieser Stelle anknüpfen und Erleichterung schaffen. Im Rahmen der Bachelorarbeit stellte sie ein E-Book für Lehrpersonen der 5. und 6. Klasse her. Es beinhaltet eine kurze, theoretische Einführung und zwölf Unterrichtsaktivitäten zur Förderung der Sprachbewusstheit. Sie sind dem entlang des Französischlehrmittels dis donc! gestaltet, was eine sinnvolle Einbettung im Unterricht ermöglicht. In dieser Arbeit sind der theoretische Hintergrund, der Produktprozess und das Produkt beschrieben und reflektiert.

Microplastics (MPs) are a major pollution concern since the start of the mass produc-tion of plastics in the 1950s. MPs form A) when plastics are produced intentionally to be part of beauty products and B) when plastics are broken down into smaller particles by sunlight, wind, and rain. This is called primary and secondary microplastics, respectively. MPs are a concern because they can carry toxic substances with them and become deposited in sediments where they are impossible to remove. Studies from China, Europe and India show that microplastics are accumulating and increasing worldwide, and reaching former pristine waters and environ-ments, such as the Arctic and natural reserves in Spain. A study from India shows that harbours and tourist beaches are especially polluted areas. When deposited on dry land, MPs can go into the so called “plastic cycle” and be transformed into carbon in sediments. This carbon can trans-form into greenhouse gases through biological processes, thus MPs are indirectly contributing to the greenhouse effect. The interest in MPs has increased over the years 2011 to 2021, as shown by an increasing trend in the number of international scientific publications. In this bachelor’s degree project, the Tisza River’s MP pollution is compared with other rivers, such as the Thames and the Elbe. The conclusion is that almost everywhere in the world, the amount of MP is increasing, especially when taking into consideration the Andong salt marsh in China and an urban river in the United Kingdom. The MP pollution is reaching an all-time high, and in this project, the importance of recycling and legislation is discussed as a means of limiting micro-plastics pollution., Mikroplast har varit ett stort föroreningsproblem sedan början av plastens massproduktion på 1950-talet. Mikroplast bildas dels när plastmaterial avsiktligt skapas för att vara del av skönhetsprodukter och liknande och dels oavsiktligt, när plast bryts ner till mindre partiklar på grund av solljus, vind och regn. Detta kallas för primär respektive sekundär mikro-plast. Mikroplast är ett stort problem eftersom de kan bära med sig giftiga ämnen och deponeras i sediment där det är omöjligt att ta bort. Studier från Kina, Europa och Indien visar att mikro-plast ansamlas i ökande koncentrationer i sediment över hela världen, och att det når tidigare helt ostörda platser såsom i den europeiska delen av Arktis och även i naturskyddade områden. Studier från Indien visar att hamnar och turiststränder är särskilt förorenade områden. När mikroplastpartiklar från luften hamnar på land kan de lagras i marken, gå in i den så kallade plastcykeln och omvandlas till kol i sediment. Detta kol kan senare omvandlas till växthusgaser genom biologiska processer, och därmed bidrar nedbrytningen av mikroplast indirekt till växt-huseffekten. Intresset för mikroplast har ökat mellan åren 2011 och 2021, när allt fler internationella vetenskapliga artiklar har publicerats. I detta kandidatarbete har Tiszaflodens innehåll av mikroplast jämförts med andra floder, såsom Themsen och Elbe. Slutsatsen är att nästan överallt i världen ökar mängden mikroplast, särskilt dras den slutsatsen när man undersöker Andong saltkärr i Kina och en stadsnära flod i Storbritannien. Spridning av mikroplast i naturen är ett ökande miljöproblem och i detta arbete betonas vikten av att återvinna och lagstifta för att komma åt föroreningsproblemet.