13th MT ARD ST3 Meeting 2025 bei DESY in Zeuthen

25 Jun 2025, 08:00 → 27 Jun 2025, 17:00 Europe/Berlin

Seminar Room 1-3 (DESY)

Local Support

The Helmholtz Initiative for Accelerator Research & Development (ARD) was established to strengthen development in accelerator physics and technology and to ensure international competitiveness. In this framework, accelerator scientists push the limits of today’s technology in a research network of six Helmholtz centers (Deutsches Elektronen-Synchrotron (DESY) in Hamburg and Zeuthen, Forschungszentrum Jülich (FZJ), Helmholtz Zentrum for Heavy Ion Research (GSI) in Darmstadt, Helmholtz Zentrum Berlin for Materials and Energy (HZB), Helmholtz Zentrum Dresden-Rossendorf (HZDR), and Karlsruhe Institute for Technology (KIT)), two Helmholtz institutes, eleven universities, two Max-Planck institutes, and the Max-Born institute.

This workshop aims to bring scientists from universities and Helmholtz centers together. It shall also serve to further strengthen collaborative projects at and between the different accelerator facilities, and educate young researchers and students participating in projects and experiments within MT-ARD-ST3.

More details can be found in the strategy + vision. 

Spokespersons of ST3: Erik Bründermann, KIT; Florian Burkart, DESY.
Center Contacts of ST3: Peter Forck, GSI; Thorsten Kamps, HZB; Michael Kuntzsch, HZDR.

 

The 2025 edition of the MT-ARD-ST3 meeting will be held in-person at DESY in Zeuthen, near Berlin.

Local organizing committee: Anne Oppelt, DESY (Zeuthen)

Hotelliste-2025.pdf

Zeuthen-Plan-2025_mit Legende.pdf

Wednesday 25 June

08:30 Registration Pre-Workshop

Pre-Workshop "Medical applications": Pre-Workshop Session I

1 FLASH radiotherapy with very high energy electrons: opportunities and challenges

The purpose of radiotherapy (RT) in cancer therapy is to destroy malignant cells while sparing normal tissue. In the last years, it has been shown that irradiations with an ultra-high dose rate (i.e., larger than about 40 Gy/s) further spare healthy tissue and has the same effect on tumour cells with respect to irradiations with conventional dose rates (i.e., of the order of 10 Gy/min). This phenomenon is called the “FLASH effect” and can lead to a novel type of RT, the FLASH RT.
Large particle accelerators, such as those available for research purposes, are valuable machines to both understand the fundamental mechanisms of the FLASH effects (which are not yet completely understood) and to advance technology for making FLASH RT widely available in the future. In particular, very-high energy electrons (VHEE), accelerated in ultra-short pulses, can penetrate deep into human body and might enable the treatment of deep-seated tumours in the future.
This talk presents the current status of FLASH RT with electrons, with particular focus on opportunities and challenges in the use of VHEE.

Speaker: Dr Elisabetta Gargioni (Department of Radiotherapy and Radio-Oncology, University Medical Center Hamburg-Eppendorf)

2 Electron and proton Flash research at the Dresden Platform for ultra-high dose-rate radiobiology

The FLASH effect describes the observation of normal tissue protection by
ultra-high dose rates (UHDR), i.e. dose delivery in a fraction of a second, at
similar tumor-killing efficacy of conventional dose delivery and promises
great benefits for radiotherapy patients. Dedicated studies are now necessary
to define a robust and optimum set of dose application parameters for FLASH
radiotherapy and to identify underlying mechanisms. These studies require
particle accelerators with high beam intensity and variable temporal dose
application characteristics for numerous radiation qualities, equipped for
preclinical radiobiological research.
The "Dresden platform" as a research hub for ultra-high dose rate radiobiology
unites clinical and research electron and proton accelerators with
radiobiology infrastructure and know-how, offering an unique environment for
preclinical FLASH effect studies.
Applying the zebrafish embryo model a comparative pre-clinical study was
conducted across the ELBE electron research accelerator, a clinical proton
cyclotron, and an advanced laser-driven proton source applied for
FLASH-relevant in vivo irradiations for the first time. The flexible beam
pulse structure at ELBE allows to demonstrate a protective effect of UHDR
irradiation up to 10^5 Gy/s average electron dose rate, compared to
conventional beam delivery over minutes. The proton experiments suggest the
consistency of the protective effect even at escalated dose rates of 10^9 Gy/s
for laser-driven relative to conventional proton beams.
Moreover, the first mice experiments investigating the response of brain
normal tissue and subcutaneous tumors for UHDR and conventional proton beams
started recently.
With the first clinical FLASH studies underway, research facilities like the
Dresden platform, addressing the open questions surrounding FLASH, are
essential to accelerate FLASH’s translation into clinical practice.

Speaker: Elke Beyreuther

3 Challenges for medical applications at ARES

This presentation will give an overview of the accelerator related challenges for medical applications. It will focus on the studies performed at ARES, DESY Hamburg.

Speaker: Florian Burkart (MIL (Injektoren und Linearbeschleuniger))

4 FLASHlab@PITZ: irradiation experiments with high doses and dose rates

FLASHlab@PITZ is a new setup for radiobiological irradiation experiments at the PITZ (Photo Injector Test stand at DESY, Zeuthen) accelerator. The main purpose is to investigate the FLASH effect and optimize irradiation parameters. The standard mode of operation is to irradiate samples with high beam current with a single bunch train (up to 4500 bunches within 1 ms). This results in several challenges, which will be presented here: 1) Achieving high stability/reproducibility (beam orbit/bunch charge) with limited feedback; 2) Beam loading; 3) High stress on the exit window (transition from vacuum to air).

Speaker: Matthias Gross (Z_PITZ (Technologie))

10:40 Coffee Break

Pre-Workshop "Medical applications": Pre-Workshop Session II

5 Dosimetry for UHDR electron beams for FLASH radiotherapy

Speaker: Dr Andreas Schüller (PTB)

6 Status of instrumentation and new dosimetric approaches for FLASH radiotherapy

Speaker: Dr Francesco Romano

12:00 Lunch break and workshop registration

7 Welcome and workshop organisation

Facility Overviews: Facility Overviews Session I

8 Facility overview DESY

Overview of the ST3 activities on the DESY Hamburg campus.

Speaker: Florian Burkart (MIL (Injektoren und Linearbeschleuniger))

9 HZDR Facility Overview

The talk will give an overview of the current activities at HZDR in the ARD-ST3 framework.

Speaker: Michael Kuntzsch (HZDR)

10 KIT Facility Overview

The Institut für Beschleunigerphysik und Technologie (IBPT) at the Karlsruhe Institute of Technology (KIT) operates the Karlsruhe Research Accelerator, KARA, with the 2.5 GeV electron storage ring, the 40 MeV to 90 MeV short-pulse linear accelerator FLUTE, and KITTEN, the KIT test field for energy efficiency and grid stability in large research infrastructures for energy-responsible research combining Europe's largest research laboratory for renewable energy, the Energy Lab, with KARA, the test facility for accelerator technologies. With the additional ATP facilities of the accelerator technology platform like the Magnet and Cryogenics Facilities, this is a perfect environment for accelerator research and technology transfer. In the future, cSTART - a compact storage ring ideally suited to study novel operation scenarios - and compact laser-plasma accelerators including a 75 TW laser system will expand the short-pulse facilities. In this presentation, we will explore and highlight cutting-edge research and technologies at KIT's advanced accelerator test facilities.

Speaker: Dr Erik Bruendermann (KIT)

14:45 Coffee Break

Facility Overviews: Facility Overviews Session II

11 PITZ facility overview

In this talk, we will give an overview of the recent progress at the photoinjector test facility at DESY in Zeuthen (PITZ). The conditioning results and characterization of Gun5.2, the update on the THz FEL, and the preparation and commissioning of the new FLASHlab@PITZ beamline will be presented.

Speaker: Xiangkun Li (Z_PITZ (Betrieb und Forschung))

12 GSI Facility Overview

GSI hosts a heavy ion accelerator facility based on several injector LINACs, a synchrotron, and two storage rings for versatile applications at fix-targets severed with various beam parameters. Moreover, the first part of FAIR (Facility for Antiproton and Ion Facility) is under technical realization, with the first beam expected in 2027.

The talk will focus on recent developments in user operation. One highlight is the simultaneous acceleration of the two ions 4He and 12C in the LINAC and synchrotron as used for cell irradiation; the C-beam modifies the cell, and the He-beam serves for diagnostics. Multi-ion species were stored in the ESR storage ring as well. For fixed target experiments, radioactive ions and pion beams were generated from the thick target. At the synchrotron using slow extraction, significant improvements are now operable, which led to an increase in the statistical accuracy of the experiments by at least a factor of 2 compared to the previous year’s operation. At the LINAC, longitudinal diagnostics are frequently used, giving significant insight into the non-standard beam dynamics. The talk will conclude with an overview of the realization of FAIR in the coming years.

Speaker: Peter Forck (GSI)

13 HZB Facility Overview

Present status and prospects for accelerator R&D at the facilities at Helmholtz-Zentrum Berlin

Speaker: Thorsten Kamps (Helmholtz-Zentrum Berlin / Humboldt-Universität Berlin)

16:15 Coffee Break

16:35 Group picture

Tutorial "THz generation and diagnostic"

14 THz Generation with Accelerators

Terahertz (THz) radiation, occupying the spectral region between microwave and infrared, has emerged as a powerful tool for applications in materials science, biology, security, and ultrafast dynamics. Accelerator-based THz sources offer distinct advantages over conventional laser-based systems, including superior pulse energy, spectral brightness, tunability, and repetition rate. This tutorial provides an overview of THz radiation generation using accelerated electron beams, with a particular focus on accelerator-based THz free-electron lasers (FELs)—among the most powerful and flexible sources of coherent THz radiation. These systems are capable of delivering both high peak and average power, with broadband or narrowband output and tunable frequencies. The tutorial will cover the fundamental physics of FEL operation, beam dynamics requirements, and the function of key accelerator components—including photo injectors, linacs, and undulators—in enabling efficient THz generation. Insights into modeling and simulation tools will also be provided and current challenges arising from the operational experience with the single-pass high-gain THz-FEL at PITZ will be discussed. Finally, future directions for the development of compact, high-repetition-rate THz FEL systems will be explored, supported by state-of-the-art examples from leading research facilities.

Speaker: Mikhail Krasilnikov (Z_PITZ (Betrieb und Forschung))

15 Sub-cycle Terahertz Diagnostics

The terahertz frequency range is located between the realms of electronics and optics in the electromagnetic spectrum. Light-matter interaction in this sub-mm wavelength range can therefore happen via both continuous and quantized processes, strongly dependent on material properties. The THz electric field can accelerate quasi-free carriers, but also excite rotational and low-lying vibrational degress of freedom as well as spin dynamics and other collective low-energy modes.

The detection methods for terahertz radiation are therefore comparably diverse. There is the class of incoherent detectors which basically measure the (electronic) heat of the absorbed THz light. These are Golay cells, pyroelectric detectors and bolometers, as well as Schottky diodes. Due to the comparably low oscillation frequency of the THz waves - 1 ps per cycle at 1 THz - coherent detection is technically feasible using short, i.e. fs, optical probe pulses. Sampling techniques, such as electro-optic sampling (EOS) or the use of photoconductive antennas enable the precise measurement of amplitude and phase of the actual THz field transients. In my presentation I will give an overview of the above mentioned THz detection methods and provide some detailed insight into our work on ultrafast THz-based diagnostics of accelerator-based light sources. At the TELBE THz facility at HZDR we employ single shot EOS to measure and adjust the timing jitter between accelerator-based THz and optical laser systems. This scheme can be extended to monitor the phase of a CEP-unstable free-electron laser, enabling phase-resolved experiments to be performed after the application of a sorting algorithm. A proof-of-principle experiment was recently carried out at the FELBE free-electron laser at HZDR. Furthermore, converting XUV pulses into THz radiation yields a powerful diagnostic tool for accurately measuring the timing and intensity of XUV sources, such as XFELs.

Speaker: Jan-Christoph Deinert (Helmholtz-Zentrum Dresden-Rossendorf)

Thursday 26 June

Beam Diagnostics: Beam diagnostics Talks

16 Terahertz streaking detection for longitudinal bunch diagnostics at FLUTE

The Karlsruhe Institute of Technology is currently exploring a compact method of longitudinal electron bunch diagnostics with femtosecond resolution that has recently been demonstrated for other parameter ranges. The experimental setup utilizes a THz-based streaking approach with resonator structures, achieving both high compactness and efficiency. In this contribution, we report on the experimental observation of streaking signals with our Compact Transverse Deflecting System, which has been successfully tested using two different resonators, an Inverse Split-Ring Resonator and a Tilted-Slit-Resonator.

Speaker: Matthias Nabinger (KIT)

17 Ultra-broadband Direct THz Detectors for Longitudinal Beam Diagnostics

Many currently operating and future FELs can generate broadband radiation at MHz repetition rate, requiring a fast diagnostic tool(response time at least on a single-digit ns scale),ultra-broadband, & robustness. We develop ultrafast-operating THz detectors based on Schottky diodes [1,2], and field-effect transistors (FET) [3] operating at room temperature.
This work presents four aspects of our newly developed detectors: (1) frequency coverage: ultra-broadband single-pixel THz detectors (based on both technologies) covering 0.05 to 54.8 THz, which essentially covers full operational spectral range of the ELBE facility in Dresden-Rossendorf, Germany, (2) ultra-wide band IF bandwidth up to ~50 GHz: this enables single shot detection of ps-scale THz pulses with response time in ps range (overcome the pile up issue faced by its counterparts), (3) bunch compression monitoring capability from single-digit pC to ~220 pC: this is essential for precise machine settings for desired beam parameter output, and (4) Radiation hardness examination of the developed detectors for their smooth operation at accelerator facilities. These detectors are tested at the ELBE facility and can be implemented at other FEL facilities.

Speaker: Rahul Yadav (Terahertz Devices and Systems, IMP , TU Darmstadt)

18 Bunch shape and longitudinal measurements for non-relativistic beams at GSI LINAC

At the heavy ion LINAC UNILAC at GSI in Darmstadt, longitudinal beam diagnostics were performed using a Bunch Shape Monitor (BSM) and a Fast Faraday Cup (FFC). These diagnostic tools allow for detailed time-resolved measurements of the longitudinal bunch structure of non-relativistic particle beams. The FFC employs a destructive measurement technique to assess the bunch-by-bunch longitudinal beam profile with a bandwidth of up to 10 GHz. In contrast, scanning the BSM integrates over multiple bunches based on the analysis of secondary electrons for an intersecting thin wire. The bandwidth of the BSM is higher than the FFC, but a scan needs several hundred beam pulses. Both devices contribute to a comprehensive understanding of the LINAC’s longitudinal phase space. Furthermore, they are essential for the optimization of beam quality and stability. The working principles of the devices, measurement procedures, and results, relevant for the beam dynamics models, are presented.

Speaker: Nimue Schmidt (GSI / TU Darmstadt)

Beam Diagnostics: Beam diagnostics Speed Talks

19 Virtual diagnostics for X-ray pulse characterization

Virtual diagnostic tools leveraging readily available input data to offer a non-invasive way to optimize Free-Electron Lasers (FEL) operation and delivery, especially when limitations with conventional diagnostics arise. This work presents a novel approach using an artificial neural network to online predict photon pulse pointing at MHz level for both soft and hard x-rays. The model input is based purely on parasitically available diagnostics of both the electron and the photon beam. The model is validated by diamond sensor measurements in order to measure the model ability to predict intra-train properties. This virtual diagnostic not only streamlines beam alignment and optimization, but is also the funding stone of a MHz-capable beam pointing stabilization. Furthermore, it further improves the online characterization of each photon pulse at MHz level.

Speaker: Farzad Jafarinia (MXL (XFEL))

20 Cryogenic Current Comparators – from Lab to Beamlines

Cryogenic Current Comparators (CCCs) for beamlines are instruments for the measurement of the intensity of charged particle beam with the following advantages: non-destructive, resolution down to nA, bunched (AC) and un-bunched (DC) beam, metrological traceability to the unit Ampere. This is achieved by exploiting low temperatures (4.2 K) and superconducting/quantum effects.
After a long phase of laboratory development and testing on accelerator rings and transport sections at GSI, CCCs are now being gradually installed and accepted as a permanent measurement system. Significant experience has been gained, especially from the first permanent installation at the CERN Antiproton Decelerator. Important parameters for the CCC sensor can now be determined in advance through the dedicated design of the instruments components. Thus, optimized performance is achieved for different application settings. One key factor for long-standing and low-impact operation is the beam cryostat. Now, maintenance-free standby time of it exceeded the milestone of 6 months. Thus, digital signal processing is becoming more and more significant. This work summarizes the key milestones and describes the upcoming installations in transport sections in the FAIR project and at CERN North Area.

Speaker: Volker Tympel (GSI GmbH, Helmholtz Institute Jena)

21 Overview of THz diagnostics at PITZ

A terahertz (THz) free-electron laser (FEL) is developed at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) to conduct proof-of-principle experiments for the European-XFEL. Narrowband 3 THz pulses with energies up to 100 μJ are generated using a single-pass, high-gain THz FEL driven by high-brightness electron beams. A dedicated diagnostic setup has been implemented for comprehensive THz radiation characterization. The pulse energy is measured using pyroelectric detectors, while spectral information is obtained via a Fourier-Transform Infrared (FTIR) spectrometer. The transverse radiation profile is captured with a THz camera. Linear polarization of the THz pulses is confirmed through a polarizer angle scan. Additionally, an in-house Michelson interferometer has been commissioned to enable spectral diagnostics at different THz stations.

Speaker: Namra Aftab (Z_PITZ (Betrieb und Forschung))

22 Measurements of the transverse emittance for 200 pC bunch charge at the ELBE SRF Gun

Radio-frequency (RF) guns are essential components of accelerator-based light sources. The superconducting continuous-wave RF (SRF) gun at ELBE, operated by Helmholtz-Zentrum Dresden-Rossendorf (HZDR), can drive multiple beamlines, including the THz beamline TELBE. TELBE is typically operated with a 200 pC bunch charge beam. The transverse emittance of the resulting beam is measured using a single-slit scan in a drift section following the gun. This poster presents the emittance measurement setup used at ELBE and shows results for the projected emittance measurements at a 200 pC bunch charge.

Speaker: Raffael Niemczyk (Helmholtz-Zentrum Dresden-Rossendorf)

23 Preparation for an electron diffraction demonstration at the ELBE SRF Gun

Ultrafast electron diffraction (UED) is a unique technique for for measuring structural and electronic dynamics with femtosecond time resolution when employed in a pump-probe arrangement. In most state-of the-art UED setups, beams with keV electron energy are utilized. The project described here aims to step up to MeV electron beams with the help of an SRF Gun. The higher coherence of the beam and the ability to achieve shorter electron pulse lengths will significantly improve the spatial and temporal resolution. An MeV-UED instrument is planned to become a central component of the DALI (Dresden Advanced Light Infrastructure) project, providing an accelerator-based infrastructure for cutting-edge materials science and life science research. At ELBE, HZDR’s user facility that provides electron beams as well as various forms of secondary radiation, including gamma rays and terahertz radiation, a first demonstration of an electron diffraction experiment using the ELBE SRF Gun is planned. The experiments will help to evaluate the potential of MeV-UED for future time-resolved studies in condensed matter and materials research. The poster summarizes the SRF Gun parameters and shows the status of the preparation of the electron diffraction setup at the ELBE SRF Gun.

Speaker: Louis Stein

24 Design of the next PCB-based BAM Demonstrator for ELBE

In 2023 a first demonstrator showed viability of a new pickup structure realized on a printed circuit board (PCB) for a bunch arrival-time monitor (BAM). Measurement shifts at ELBE validated the simulations and motivated the further pursuit of this approach. A few shortcomings were deliberately accepted to simplify production and increase the probability of successful measurement for the first demonstrator. Thus, a second demonstrator was designed and is currently manufactured. It will overcome most of the shortcomings, to further exploit the potential of the PCB-based BAM. It will allow for a higher bandwidth and provide a higher voltage signal compared to the existing demonstrator. Additionally, some practical problems found during construction and operation of the first demonstrator are tackled in the new design.

Speaker: Bernhard Erich Juergen Scheible (THM)

25 Temporal Resolution Analysis of the $\beta$-Dependency of Radially Coupled FFC Designs

In the last few years, we investigated a new type of Fast Faraday Cups (FFC). This type radially couples the bunch to the inner conductor of a coaxial geometry. The main benefit of this FFC is that two methods to suppress secondary electrons (SE) from impacting the output signal can be applied: by a bias potential and geometrically, through hitting the inner conductor only inside a drill hole. Aside from the reduction of the total amount of SE through the geometrical limitation, the drill hole also leads to a temporal separation of the primary signal from the SE signal. It is even possible to separate them completely. However, a higher temporal separation contradicts the maximum bandwidth, and hence the temporal resolution, of this FFC type. Two versions of these radially coupled FFCs have been tested at the hadron facilities GSI UNILAC, PHELIX, and FRANZ. The focus of these tests was on improving geometrical suppression.
In this contribution, we examine the potential usage of this type of FFC for high $\beta$ lepton facilities, evaluating the technical limitations through CST simulations by comparing the existing RCFFCs with a bandwidth-optimized version.

Speaker: Stephan Klaproth (Technische Hochschule Mittelhessen)

26 Latest Advancements of a Compact Electro-optical Bunch Length Detector

Laser-based electro-optic detection (EOD) has been a valuable method to measure the longitudinal electron bunch shape with sub-ps resolution for almost a decade now, but it has always been a tool for expert use.
At European XFEL and FLASH, we are advancing the EOD from an expert device to a user friendly tool, with new operator interface and automated, server-based procedures for laser locking, time calibration and online data analysis.
The system at European XFEL is currently used in an electro-optic spectral decoding configuration (EOSD), but the implementation of advanced reconstruction algorithms (Diversity Enhanced EO Spectral Decoding, DEOS) is ongoing to surpass resolution limitations when recording broadband THz radiation over long temporal acquisition windows.

Speaker: Marie Kristin Czwalinna (DESY, MSK)

27 Femtosecond Radiative Longitudinal Diagnostic Techniques Employed at ARES

Femtosecond and sub-femtosecond longitudinal diagnostics are required to accurately characterise the short bunches required by novel acceleration techniques. For femto-second bunch lengths, the coherence of transition radiation starts to reach the near-infrared to optical regime, where the spectrum can be easily detected, rendering information on the form factor and bunch length. The ARES (Accelerator Research Experiment at SINBAD) linear accelerator is well suited to the employment of this diagnostic technique for the characterisation of short bunches.

The Smith-Purcell radiation mechanism has been extensively studied from metallic gratings, however not much experimental data has been published with respect to dielectric gratings as charged particle beam diagnostic devices. Detection of the radiation at the substrate side is expected to be advantageous and the spectral properties of the radiation can be tailored by careful design of the grating structure geometry. Dielectric gratings can be produced with optical wavelength periodicities and the shapes can be controlled with nano-meter precision, showing potential for femtosecond longitudinal diagnostic applications.

Speaker: Blae Stacey (MIL (Injektoren und Linearbeschleuniger))

28 First prototype measurements with an electro-optical bunch profile monitor for FCC-ee

The future circular electron-positron collider (FCC-ee) is designed for highest luminosity to enhance the precision of high-energy particle physics experiments, spanning energies from the Z pole to the $\text{t}\bar{\text{t}}$ threshold. As outlined in its conceptual design report, high-precision measurements of the longitudinal bunch profile are required across multiple operation modes, which presents key challenges for beam instrumentation. As part of the feasibility study, a concept for an electro-optical (EO) bunch profile monitor has been developed to address these challenges, building on the existing EO beam diagnostic at the Karlsruhe Research Accelerator (KARA) at KIT. The first EO monitor prototype for FCC-ee features a novel crystal-holder design using prisms, enabling a single-pass setup crucial for measuring the long bunches during Z operation.
This contribution presents the first measurement results of the EO monitor prototype for FCC-ee, which were obtained in the in-air test stand at the CERN Linear Electron Accelerator for Research (CLEAR).

Speaker: Micha Reißig (Karlsruher Institut für Technologie (KIT))

29 High-reliability bunch arrival time monitor with fs precision

The DESY's Bunch Arrival Time Monitors (BAM) are state-of-the-art sensors based on an electro-optical detection principle, that delivers information on the bunch timing with femtosecond-level precision. Recent developments concerning the device construction and automation resulted in the BAM system stability, that enables year-long participation on standard accelerator operation. Such level of stability is unprecedented, and gives access to observation of longer-term phenomena that influence the machine synchronization. Additional advances in the performance of the BAMs attacking sub-fs resolution enabled synchronization of the electron beam with a world-leading precision of less than 3fs at European XFEL.

Speaker: Jiri Kral (MSK (Strahlkontrollen))

30 Time-resolved measurements of transverse beam excitation in an electron storage ring

In the Karlsruhe Research Accelerator (KARA), electron beams of up to 200 mA are stored with an energy of 2.5 GeV, while injection is performed at 500 MeV. At the injection energy, the beam life time and the injection efficiency depend largely on Touschek scattering. As a counter-measure, the beam size can be enlarged transversally by an excitiing modulation, e.g. applied via a strip-line.

Here, we examine different excitation strategies and their effects on beam size and the beam orbit. The ultra-fast line camera KALYPSO is used to measure the transverse beam profile via the emitted synchrotron radiation on a turn-by-turn basis.

Speaker: Marvin Noll (KIT)

31 Beam Diagnostics for Measurement of longitudinal Beam Properties at UNILAC

During recent beamtimes at GSI we have used various diagnostics devices for characterization of the longitudinal properties of the UNILAC beam. Beam Position Monitors (BPM), Secondary Electron Emission Grids (SEM-Grids) - originally developed for the FAIR proton Linac - have been employed as well as a Feschenko Type Bunch Shape Monitor (BSM) to measure beam displacement behind dispersive sections in combination with bunch lengths and shape to derive longitudinal emittance. We present the diagnostics tools and explain the basic measurement principle.

Speaker: Thomas Sieber (GSI)

32 High-power laser system synchronization optimization

High-power laser system synchronization optimization

Mohammed Salman$^{1,2}$, Dr. Michael Kuntzsch$^2$, Prof. Dr.-Ing. Andreas Penirschke$^1$
$^1$Technische Hochschule Mittelhessen (THM), Friedberg (Hessen), Germany
$^2$Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Sachsen), Germany

Synchronization systems are critical for ensuring precise timing and coordination in various scientific and technological applications, particularly in high-power laser laboratories and particle accelerators. However, the performance of these systems is often hindered by factors such as phase noise and jitter due to the distance or ambient effects. These phenomena introduce instability and inaccuracies in timing signals, necessitating the use of locking electronics and actively timing-stabilized fibre links. At the HZDR accelerator facility (ELBE), we are focused on optimizing the synchronization system, especially between high-power lasers and the accelerator which operate at 78 MHz, to enhance precision and stability. The efforts include the commissioning of a Fibre-to-RF receiver at the end-user (end of the fibre link) and analysing phase and amplitude noise there at the Laser end-user to establish baseline performance metrics. Additionally, examine and optimize the performance of locking electronics to stabilize the laser output, and calibrate the Balanced Optical-Microwave Phase Detector by fine-tuning its electronic components and controllers. Finally, update core timing-stabilized links and fibre laser to a new Menhir 156 MHz laser and introduce a pulse-picker to reduce the repetition rate to the needed 78MHz and develop a system to generate the RF reference signal to drive the pulse picker. These efforts to improve the reliability and efficiency of laser systems, aim to reach synchronization jitter values of less than 100 fs, ensuring they meet the stringent requirements of advanced scientific experiments and industrial applications.

Speaker: Mohammed Salman

11:03 Coffee Break

Beam Diagnostics: Beam diagnostics Poster Session

11:55 Lunch break

Participants are free to lunch on their own on Adlershof campus.

Tutorial: "Energy efficient accelerator operation": Tutorial Energy efficient accelerator operation

33 Energy efficient accelerator operation

Speaker: Dr Nuria Catalan Lasheras (CERN)

34 From KIT to EU level: KITTEN and RF2.0 for sustainable operations at large research infrastructures

Recently, the societal challenges in a view to transition into a carbon-neutral economy, and to minimize the burden on our environment especially in terms of material and energy usage from large research infrastructures as accelerator facilities have enormously increased.
This work presents an overview of the KITTEN (KIT Test center for Energy efficiency and Network stability at large research infrastructures) efforts on implementing and operating research facilities sustainably. At KITTEN, scientists from the KARA accelerator and the Energy Lab (one of Europe's largest infrastructures for renewable energies) collaborate to investigate energy efficient operations.
The Horizon Europe Research Facility 2.0 (RF2.0), a project towards a more energy efficient path, is also introduced. Through the RF2.0, the transfer of the KITTEN comprehensive approach on solving the energy management problem to other European facilities has been made possible.

Speaker: Falastine Abusaif (KIT)

35 Can we improve sustainability of large scale SRF accelerator driven science?

To start with a prominent example, the LHC at CERN transforms yearly electric energy, which is comparable
to a twohundred thousand citizen town in a developed country or the whole Kanton of Geneva with half a milion inhabitants.
The European XFEL's RF system alone requires 5 MW of power input. In the view of these numbers and regarding how fast
human driven climate change is accelerating, especially actually in Europe, any large scale future scientific installation
needs to tackle the problem to significantly reduce the required power for accelerator driven experiments and also to maximize
the figure of merit, which could be for example luminosity or brilliance per kW.
Energy recovery linacs (ERL) form a class of SRF driven accelerators, which are inherently efficient, as there is close to zero net power transfer
between the accelerated beam and the RF driving the cavities. However, even here is still room for improvement. SRF cavities at low
beam-loading are driven overcoupled for stability reasons to counter cavity detuning. For Niobium cavities, the optimum operation
temperature is in the range of 1.8-2K, thus that the real cryogenics efficency is on the order of per mille. Can we reduce this required RF power and improve on cryogenic efficency?
As a recent example to work on these problems, the EU Horizon funded iSAS [1] program has targeted these main "energy hungry" technologies by studying
ERL technology within the PERLE project as a demonstrator for the LHeC electron-hadron collider, the tuning of SRF cavities by
means of ferroelectric fact reactive tuner to reduce RF power and to study coating of Nb3Sn on Copper host cavities for higher temperature SRF operation.
In this contribution, the energy efficency of ERLs will be discussed and the means to further improve it in the framework
of the iSAS program.

[1] https://isas.ijclab.in2p3.fr/

Speaker: Dr Axel Neumann (HZB)

Beam Control: Beam control Talks

36 Sub-fs reference timing - Model based optimization of the EuXFEL sychronisation system

Sub-femtosecond short and long-term stable timing reference signals for the LLRF systems, longitudinal beam diagnostics and experiment laser systems are the next milestone on the road towards more advanced few-femtosecond and attosecond resolved experiments at the latest generation of FELs such as FLASH (2020+) and European XFEL. Using a comprehensive model of the laser-based synchronization system at European XFEL, feedback parameters of the actual system were optimized to achieve sub-fs timing stability over 7km of transmission distance. The model also allows for jitter budget analysis and provides a comprehensive roadmap for necessary future R&D efforts.

Speaker: Maximilian Schuette (MSK (Strahlkontrollen))

37 Sub-fs SRF cavity control at CMTB

Using a novel RF receiver technique based on a carrier-suppression interferometer (CSI), we have achieved sub-femtosecond RF field control stability on a 1.3GHz CW superconducting RF (SRF) cavity at the Cryo-Module Test Bench (CMTB) at DESY. The CSI provides an improved RF sensitivity of a factor 100 and is used in addition to the standard RF down-converter. The CSI signal is added as an amplified error signal to the feedback controller. Performance evaluation is done by an out-of-loop CSI, which is capable to measure the stability of the cavity field relative to the RF reference from the main oscillator.

Speaker: Matthias Hoffmann (MSK (Strahlkontrollen))

38 Efficient Accelerator Operation with Artificial Intelligence Based Optimization Methods

Tuning injectors is a challenging task for the operation of accelerator facilities and synchrotron light sources,
particularly during the commissioning phase. Efficient tuning of the transfer line is essential for ensuring
optimal beam transport and injection efficiency. This process is further complicated by challenges such as
beam misalignment in quadrupole magnets, which can degrade beam quality and disrupt operations. Traditional
tuning methods are often time-consuming and insufficient for addressing the complexities of highdimensional
parameter spaces.
In this work, we explore the use of advanced AI methods, including Bayesian optimization, to automate and
improve the tuning process. Initial results, demonstrated on the transfer line of KARA (Karlsruhe Research
Accelerator) at KIT (Karlsruhe Institute of Technology), show promising improvements in beam alignment
and transport efficiency, representing first steps toward more efficient and reliable accelerator operation.
This study is part of the RF2.0 project, funded by the Horizon Europe program of the European Commission,
which focuses on advancing energy-efficient solutions for particle accelerators.

Speaker: Evangelos Matzoukas (Karlsruhe Institute of Technology)

39 Automation & optimization with classical optimizer towards RL at GSI with Geoff

Automation & Optimization with Classical Optimizer towards RL at GSI with Geoff

Geoff is an open-source optimization framework developed at CERN and further maintained in collaboration with GSI as part of the EURO-LABS project. It provides a standardized interface to optimization problems, enabling seamless switching between classical optimizers and reinforcement learning approaches. In addition, utility functions and tools within Geoff help accelerate the development of optimization workflows. Using the example of beam injection into SIS18 at GSI, we illustrate how optimization can evolve from classical optimizer to reinforcement learning.

Speaker: Sabrina Appel (GSI)

Beam Control: Beam control Speed Talks

40 The DAMC-DS5014DR, a high-speed Digitizer, leveraging the cutting-edge AMD ZYNQ Ultrascale+ RFSoC Technology in a MicroTCA.4 form factor.

This talk reviews the DESY MicroTCA card, DAMC-DS5014DR, designed for high-speed multi-channel data acquisition. Based on AMD Zynq Ultrascale RFSoC ZU47DR, it features eight 14-bit, 5-GSPS ADCs, eight 14-bit, 10-GSPS DACs, extensive programmable logic (PL) resources, and an ARM-processing system (PS). In this card, the AC or DC coupling options ensure that the input signals are pre-conditioned and fed to the ADCs that follow the MicroTCA.4 concept allows users to design a custom RTM specifically designed for signal conditioning. The board offers a QSFP28+ interface that supports 100Gb Ethernet or optical PCIe Gen.4 x4 (16 Gbps/lane) data streaming, while the second set of PCIe Gen.4.0 x8 available on the card provides data transfer to the MicroTCA.4 backplane. Eight independent timing/trigger inputs capture event-coincident data. Three 16-GByte, 64-bit DDR4 memory banks foreseen on this card handle high-throughput data and are especially useful for processing fast data streams. A high-frequency clock synthesizer generates synchronized clocks for ADCs, DACs, and PL, sourced from the backplane, front panel, or a stable local oscillator. The board will follow the CERN white Rabbit, which allows the receipt of white Rabbit Trigger signals via the QSFP Module. Supported by AMD tools (Vivado, HLS, Yocto, Petalinux, SDSoC, SDAccel), the DAMC-DS5014DR combines a large FPGA, fast ADCs/DACs, and a powerful CPU to meet high-speed digitization and processing needs while reducing development time.

Speaker: Behzad Boghrati (MSK (Strahlkontrollen))

41 System-on-Chip based magnet control in a MicroTCA system

This poster presents a master’s thesis which outlines a concept for the migration of the DESY II magnet control from the VMEbus standard to the MicroTCA standard. A special focus is placed on meeting the real-time requirements, which were achieved in the VME system by using the real-time operating system VxWorks.
The central concept is the system-on-chip (SoC) approach, whereby the control loops of all six magnet circuits, which were executed on the central CPU in the VME system, are now outsourced to individual Zynq7000 SoCs. Thereby the workload for a single processor is significantly reduced. Real-time critical tasks are executed on the SoC, such as counting trigger and pulse signals from the current measurement on the Programmable Logic (PL) and calculations and control algorithms on the Processing System (PS). PL-PS interrupts and the AXI4-Lite protocol are used for data communication between these two components. The CPU module of the MicroTCA crate implements the control system server. For the communication between the CPU and the SoC-AMC modules, PCIe on the AMC backplane is used.
The SoC approach meets the real-time requirement of the old system. The results of this project provide a concept for using the MicroTCA standard in the DESY II magnet control.

Speaker: Jana Miericke (MPC (M Power Supplies))

42 Koopman meets Kalman: A deep learning approach to model radio frequency cavity detuning

In the light of recent developments to employ high-Q superconducting cavities to reduce the energy consumption of particle accelerators, the problem of minimizing cavity detuning becomes highly relevant. Meanwhile, radio frequency cavities are known for their non-stationary behavior, so finding a proper modeling approach is crucial for any model-based detuning control. In this contribution, we present a data-driven modeling framework that combines two complementary perspectives on dynamical systems: the Koopman operator approach, which captures global patterns in cavity behavior, and Kalman-inspired ideas, which enable local, adaptive adjustments in response to changing cavity conditions. Following this, our architecture 1) separates long-term structure from local variability and then 2) blends them using a tunable weighting mechanism. We demonstrate the effectiveness of this approach on both synthetic cavity data and real-world cavity measurements. The results show a potential to make the detuning control more robust to the non-stationary cavity behavior.

Speaker: Andrei Maalberg (Helmholtz-Zentrum Berlin)

43 Feedback Optimization on the EuXFEL Electron Dump Beamline

At the European XFEL, the main beam dump serves to absorb all electron bunches that are not required for the downstream scientific experiments. Due to the large beam power of the accelerator, controlling the dump temperature is a crucial component in its operation. Currently, this is done in an open-loop feed-forward manner. However, due to unforeseen drifts and changes in the setup of the accelerator, sporadic manual interventions by the machine operators are necessary to maintain regular operation, binding attention that could be spend better on other tasks.

For this reason, we present feedback optimization as a powerful and flexible solutions to automatically control the beam position along the main EuXFEL electron beam dump line. Two variants are investigated, model-based relying on the Cheetah particle accelerator optics simulation and model-free learning the model response over time, and the controller has been evaluated on the accelerator successfully.

Speaker: Christian Hespe (MSK (Strahlkontrollen))

44 Adaptive feedforward control of superconducting resonators on RFSoC

RFSoC has a number of advantages to reduce the costs associated with designing and debugging control algorithms for large and small research institutes: an adjustable PLL and multiple ADC/DACs capable of mixing frequencies and tuning the Nyquist operating zone and bandwidth, support for DSP algorithm developers and design tool vendors. Accelerated prototyping of the control system on RFSoC has given our institute the opportunity to develop a number of application-specific control algorithms: fully digital PLL, self-excitation loop, Tesla resonator simulator. The latest addition is an adaptive feedforward controller, previously developed and now being tested at the Hobicat test facility. This controller is characterized by its adaptability to external microphonic low-frequency excitations, which is important for systems with high quality factor, thus reducing the cost of maintaining system life.

Speaker: Dr Andriy Ushakov (Senior Researcher)

45 Application of Carrier Suppressing Interferometry in the MAGO Project

The purpose of the MAGO (Microwave Apparatus for Gravitational-wave Observation) project is to detect high-frequency gravitational waves (GWs) using a superconducting radio-frequency (RF) cavity. The detection principle relies on heterodyne detection. MAGO cavity consists of two identical coupled cells. Coupling of the two cells, produce two close resonant modes(zero and pi mode). When the zero mode is externally excited, interactions between an incident GW and the cavity can induce a transfer of power to the π mode (Heterodyning). This power transfer enables GW detection.Due to the small frequency bant gap between the two modes, the phase noise of the excitation signal (driving the zero mode) plays a critical role in the detection process. To avoid false signal detection, it is essential to isolate the π mode signal from the phase noise of the exciter.

Carrier Suppressing Interferometry (CSI) is a promising technique for measuring extremely low levels of phase noise. Recent advancements by the DESY MSK group have enabled phase noise measurements down to the -210 dBc/Hz level. This capability makes CSI a strong candidate for the signal extraction scheme in the MAGO project. In this presentation, the progress of CSI implementation within the MAGO detection system will be outlined.

Speaker: Can Dokuyucu (MSK (Strahlkontrollen))

46 Modified Active Disturbance Rejection Control for microphonics reduction in SRF cavities

In low beam loading applications, operating SRF cavities with high loaded quality factors is currently one of the main efforts in order to reduce the electric power needed for particle acceleration. This reduction is a key factor for current and future facilities as it 1) decreases the initial invest (tube based amplifiers can be substituted by solid state amplifiers) and 2) reduces the plug power, lowering thus the operation costs and making the accelerators more sustainable. In this sense, controlling the microphonics detuning of the SRF cavities is fundamental to allow high QL operation. Here we present the results of a modified Active Disturbance Rejection Control used to drive the piezoactuators feedback in a TESLA cavity at HZB’s HoBiCaT teststand.

Speaker: Pablo Echevarria (Helmholtz-Zentrum Berlin)

47 Use of DESY's Open-Source FPGA Framework in the LISA (Laser Interferometer Space Antenna) Mission

The Laser Interferometer Space Antenna (LISA) mission is one of the most ambitious space observatories developed by the European Space Agency (ESA) in collaboration with the National Aeronautics and Space Administration (NASA). Its objective is to detect low-frequency gravitational waves—signals that are otherwise undetectable from Earth due to environmental noise. These waves, which propagate through spacetime at the speed of light, are generated by massive astrophysical events.

DESY, through its MSK group, is contributing to this groundbreaking mission by developing a high-precision phasemeter system capable of measuring laser phase shifts. A key enabler of this development is the FWK framework—an open-source FPGA development platform specifically designed to support MicroTCA-based hardware in large-scale scientific applications. In this presentation, the role of FWK in the LISA project will be showcased, highlighting its impact on firmware development workflows, integration with MicroTCA hardware, and its value in facilitating FPGA development in the context of complex and demanding research infrastructures.

Speaker: Dr Gianmarco Ricci (MSK (Strahlkontrollen))

48 The progress report on Gun5.2 Operation

A new generation of normal conducting L-Band RF guns (Gun5) is under development at the Photo Injector Test facility at DESY in Zeuthen (PITZ), with the goal to provide a high-quality electron source for superconducting linac driven free-electron lasers like FLASH and European XFEL. In addition to the improved cell geometry and cooling concept implemented in the new design, which allow for long RF pulse durations of up to 1 ms at a repetition rate of 10 Hz with gradients of up to 60 MV/m at the cathode, the new solenoid alignment system, the recently developed cathode contact spring, and new RF diagnostics possibilities aim to provide a higher-quality beam and improved gun operation performance. In this contribution we summarize the experience from the Gun5.2 commissioning and operation, and state the key improvements compared to previous guns.

Speaker: Avni Aksoy (Z_PITZ (Beschleunigerphysik))

15:50 Coffee Break

Beam Control: Beam control Poster Session

16:00 Coffee Break

PITZ visit

19:00 Dinner

Friday 27 June

Beam Dynamics: Beam dynamics Talks

49 4D coupled transverse phase space investigations at PITZ

Measurements of the transverse phase space are crucial for characterizing the performance of the electron gun in a photo injector. At the Photo Injector Test facility at DESY in Zeuthen (PITZ), the 2D x and y phase spaces are separately measured with a slit-screen emittance scanner directly after the RF booster where the energy is ~20 MeV. These 2D measurements can then combined with post processing using the Virtual Pepper Pot (VPP) method to reconstruct the 4D transverse phase space. Analyzing recent phase space measurements at PITZ with the VPP revealed significant x-y coupling. Presented here are investigations of the source and mitigation of the 4D coupling.

Speaker: Christopher James Richard (Z_PITZ (Betrieb und Forschung))

50 First beam commissioning of the SRF photoelectron gun at HZB

The versatile 1.3 GHz superconducting radio-frequency (SRF) gun at HZB succesfully generated first photoemission beam from a high quantum efficiency (QE) multi-alkali photocathode. This demonstrates worldwide first beam operation of a SRF gun at high repetition rate and with a robust multi-alkali Na-based photoemissionn source. The setup of the test and all sub-systems is described. The latest results of SRF commissioning, cavity performance, photocathode QE measurements and beam parameter exploration campaigns is presented in the talk.

Speaker: Thorsten Kamps (Helmholtz-Zentrum Berlin / Humboldt-Universität Berlin)

51 Simulation-based optimization of the injection of ultrashort non-Gaussian electron beams into a storage ring

The compact STorage ring for Accelerator Research and Technology (cSTART) project at the Karlsruhe Institute of Technology (KIT, Germany) aims to explore non-equilibrium electron beam dynamics and injection of laser-plasma accelerator (LPA) bunches for the first time. The Very Large Acceptance compact Storage Ring (VLA-cSR) is also filled by a second injector that delivers ultra-short bunches from the Ferninfrarot Linac- Und Test-Experiment (FLUTE). Injection from FLUTE into the VLA-cSR is achieved via a complex 3D injection line featuring tilted deflections, negative dispersion, and extreme compression to femtosecond bunch lengths.

From this transport, the bunch develops pronounced non-Gaussian tails; nevertheless, near the injection point, it is crucial to ensure matching to both the dynamic aperture and the periodic solutions of the storage ring dynamics. With a total of 25 quadrupoles, conventional optimization methods become impractical. This contribution presents the development of the magnet optics to meet these extreme requirements. The optimization task was divided into two parts: longitudinal compression was partially addressed using a surrogate model, while transverse matching is currently being pursued with Bayesian optimization.

Speaker: Jens Schäfer (KIT IBPT)

52 XFEL R&D Highlights

EuXFEL is one of the leading FEL facilities worldwide. It is constantly expanding its delivery capabilities in order to meet the photon user requirements. This talk gives an overview of the active research in the area of attosecond pulse generation, coherence control and twin-pulses generation happening at DESY and EuXFEL.

Speaker: Marc Guetg (MXL (XFEL))

Beam Dynamics: Beam dynamics Speed Talks

53 Optimizing EuXFEL Photoinjector Performance via Laser Shaping Approach

The OPAL-FEL project aims to advance European XFEL capabilities for lasing in the sub angstrom regime through the generation of low-emittance electron beams. Within OPAL-FEL, we have applied a combined spatial and temporal driver laser shaping technique to optimize photoinjector emittance. Beam dynamics simulations are performed to demonstrate that the applied approach significantly reduces electron beam emittance. Preliminary experimental results have shown reasonably good SASE performance using shaped electron bunches. Both numerical and experimental results will be shown.

Speaker: Meng Cai (MXL (XFEL))

54 Quasi-isochronous conditions and high order terms of momentum compaction factor at the compact Storage Ring

The compact storage ring project for accelerator research and technology (cSTART) is realized at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). Flexible lattice of a ring benefits variety of operation modes. Different physical experiments are planned at cSTART. In particular, deep variation of momentum compaction factor with simultaneous control of high order terms of alpha would demonstrate the capture and storage of ultra-short bunches of electrons in a circular accelerator. Computer studies of linear and non-linear beam dynamics were performed with an objective to estimate arrangement and performance of dedicated three pole chican magnets to provide quasi-isochronous conditions for electrons. Additonal families of so called “longitudinal” sextupoles and octupoles were added in a ring model to control slope and curvature of momentum compaction factor as function of energy offset of particles in a bunch.

Speaker: Alexander PAPASH (Karlsrueh Institute of Technology)

55 S2E Simulation of THz FEL at PITZ with Bunch Compressor

The PITZ accelerator comprises a radiofrequency (RF) photogun and an RF booster cavity, capable of generating electron beams with bunch charges of several nC and momenta of up to 22 MeV/c. To achieve higher beam current which is a key parameter for the single-pass high-gain THz FEL, bunch length compression using a four-dipole chicane installed upstream of the undulator has been studied. Using a gaussian photocathode laser, significantly higher beam currents have been obtained, exhibiting flattop profiles with sharp trailing-edge spikes. This poster presents the strong seeding effects from the steep trailing edge of the current profile observed from Genesis simulations. The limited improvement of the radiation energy due to the longitudinal phase space smearing from strong short-range longitudinal space charge forces will also be discussed.

Speaker: Biaobin Li (Z_PITZ (Betrieb und Forschung))

56 Beam dynamics optimization for high-brightness photo injector with various photocathode laser pulse shapes

PITZ at DESY Zeuthen focuses on the development and optimization of high-brightness electron sources for the European XFEL. At PITZ, a thorough study of factors influencing emittance growth is carried out. Emittance growth due to space charge can be managed through precise laser pulse shaping techniques. 4D and 6D Integral brightness that incorporates not only the emittance, but electron beam current profile and longitudinal phase space properties from laser pulse shapes are proposed as objectives for the optimization. Multiobjectve optimization studies with ASTRA are aimed at not only minimizing emittance but maximizing brightness for various laser temporal profiles and widths. A comparative analysis for Gaussian, flattop, ellipsoidal and inverted parabolic laser profiles is presented to compare their efficiency not only in terms of emittance but 4D and 6D brightness.

Speaker: Sumaira Zeeshan (Z_PITZ (Betrieb und Forschung))

57 Preliminary Simulation on Terahertz superradiation generation at PITZ

The photoinjector test facility at DESY in Zeuthen (PITZ) is developing a THz free electron laser using its high brightness electron beams. A start-to-end (S2E) simulation for generating superradiation at 3 THz is performed to explore the potential of producing few-cycle high-energy terahertz radiation using the current THz beamline. The results will be discussed in this poster.

Speaker: Duo Xu (Z_PITZ (Beschleunigerphysik))

58 Nonlinear bunch compressors for DALI

HZDR is planning a successor facility for the ELBE radiation source: the Dresden Advanced Light Infrastructure DALI. DALI will include a positron source, an MeV UED instrument, an optical klystron mid-IR source for 3 to 30 THz, requiring bunch lengths of 10 to 20 wavelengths, and a superradiant THz source for frequencies up to 3 THz. The bunch length for the superradiant source needs to be shorter than the radiation wavelength 100 µm, which is expected to require magnetic linearization.
Several options for the envisaged nonlinear bunch compressors will be discussed.

Speaker: Arthur Delan (Helmholtz-Zentrum Dresden-Rossendorf)

59 Quasi-isochronous conditions and high order terms of momentum compaction factor at the compact Storage Ring

The compact storage ring project for accelerator research and technology (cSTART) is realized at the Institute for Beam Physics and Technology of the Karlsruhe Institute of Technology (KIT). Flexible lattice of a ring benefits variety of operation modes. Different physical experiments including direct injection and circulation of Laser Plasma Accelerator (LPA) electrons are planned at cSTART. Deep variation of momentum compaction factor with simultaneous control of high order terms of alpha would demonstrate the capture and storage of ultra-short bunches of electrons in a circular accelerator. Computer studies of linear and non-linear beam dynamics were performed with an objective to estimate arrangement and performance of dedicated three pole chican magnets to provide quasi-isochronous conditions for electrons. Additional families of so called “longitudinal” sextupoles and octupoles were added in a ring to control slope and curvature of momentum compaction factor as function of energy offset of particles in a bunch.

Speaker: Alexander PAPASH (Karlsrueh Institute of Technology)

MT_ARD_POSTER_A0.pdf

10:50 Coffee break

Beam Dynamics: Beam dynamics Poster Session

Strategy discussion

Final discussion and close-out

12:50 Take-away lunch