Patrik Schönfeldt

Patrik Schönfeldt
DLR Institute of Networked Energy Systems · Energy Systems Technology

Dr. rer. Nat.

About

72
Publications
5,471
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345
Citations
Introduction
Patrik Schönfeldt works at the DLR Institute of Networked Energy Systems, developing tools and methods to assess energy supply systems based on renewable sources. During his PhD thesis, he designed the high-performance hybrid particle tracking code "Inovesa" that models the motions of highly compressed ensembles of electron in storage rings and coped with high bandwidth measurement data coming from a 2.7 MHz line camera.
Additional affiliations
September 2018 - present
DLR Institute of Networked Energy Systems
Position
  • PostDoc Position
February 2014 - July 2018
Karlsruhe Institute of Technology
Position
  • PhD Student
Education
February 2014 - July 2018
Karlsruhe Institute of Technology
Field of study
  • Accelerator Physics
October 2007 - November 2013

Publications

Publications (72)
Article
Using arbitrary periodic pulse patterns we show the enhancement of specific frequencies in a frequency comb. The envelope of a regular frequency comb originates from equally spaced, identical pulses and mimics the single pulse spectrum. We investigated spectra originating from the periodic emission of pulse trains with gaps and individual pulse hei...
Article
Full-text available
The numerical solution of the Vlasov-Fokker-Planck equation is a well established method to simulate the dynamics, including the self-interaction with its own wake field, of an electron bunch in a storage ring. In this paper we present Inovesa, a modularly extensible program that uses OpenCL to massively parallelize the computation. It allows a sta...
Article
Full-text available
The planning and decision-making for a distributed energy supply concept in complex actor structures like in districts calls for the approach to be highly structured. Here, a strategy with strong use of energetic simulations is developed, the core elements are presented, and research gaps are identified. The exemplary implementation is shown using...
Article
Full-text available
Energy system modelling is of high importance to investigate different scenarios in their technical, economical and environmental feasibility. The interplay of different technologies and energy flows in respective models can be represented as directed graphs in a generic but comprehensible formalism. However, additional effort is needed to create s...
Thesis
Full-text available
The shape of an electron bunch has a tremendous impact on its emission of synchrotron radiation. Especially the formation of sub-structures can increase the yield in the THz region. This thesis investigates the micro-bunching instability, a mechanism where structures form due to self-interaction of the electrons with their own wake-field. The metho...
Article
Full-text available
Since the Paris Agreement in 2016, the goals of limiting climate change and moving toward climate resilience stand. With a share of about 80% of global CO2 emissions, the energy sector is an essential driver for these goals. A shift to low-carbon energy production and a decentralized system for more efficient energy transmission distribution is nec...
Conference Paper
Linear programming is used as a standard tool for optimizing unit commitment or power flows in energy supply systems. For heat supply systems, however, it faces a relevant limitation: For them, energy yield depends on the output temperature, thus, both quantities would have to be optimized simultaneously and the resulting problem is quadratic. As a...
Preprint
Full-text available
The optimal combination of energy conversion and storage technologies with local energy demand is a key but in its result not obvious challenge of distributed energy. Although a variety of possible approaches to the optimal design of limited technology selections can be found in the literature, the previous design step, the actual technology select...
Preprint
Full-text available
The optimal combination of energy conversion and storage technologies with local energy demand is a key but in its result not obvious challenge of distributed energy. Although a variety of possible approaches to the optimal design of limited technology selections can be found in the literature, the previous design step, the actual technology select...
Presentation
Full-text available
To meet the 1.5 °C goal of the Paris agreement, a rapid transition of energy supply is needed. Not only fossil based thermal power plants have to be replaced, but also 89 % of the global heat supply. While this parallel transition might be challenging, it also offers the chance to lift the potential of mutual benefits, i.e., the electricity sector...
Preprint
Full-text available
Since the Paris Agreement in 2016, the goals of limiting climate change and moving toward climate resilience stand. With a share of about 80 % of global CO2 emissions, the energy sector is an essential driver for these goals. A shift to low-carbon energy production and a decentralized system for more efficient energy transmission distribution is ne...
Article
Full-text available
We present a method to turn the results of model-based optimisations into resilient and comprehensible control strategies. Our approach is to define priority lists for all available technologies in a district energy system. Using linear discriminant analysis and the results of the optimisations, these are then assigned to discrete time steps using...
Preprint
Full-text available
We present a method to turn results of model-based optimisations into resilient and comprehensible control strategies. Our approach is to define priority lists for all available technologies in a district energy system. Using linear discriminant analysis and the results of the optimisations, these are then assigned to discrete time steps using a se...
Article
Full-text available
There are 1454 district heating systems in Germany. Most of them are fossil based and with high temperature levels, which is neither efficient nor sustainable and needs to be changed for reaching the 2050 climate goals. In this paper, we present a case study for transforming a high to low temperature district heating system which is more suitable f...
Conference Paper
For a successful energy transition, the renewable energy supply in the sectors of electricity, mobility and heat should be equally addressed. This paper presents a suitable method for performing a comprehensive hazard and risk analysis of such a multi-modal local energy system. The method allows identifying trends in the level of critical risks of...
Preprint
Full-text available
Linear programming is used as a standard tool for optimising unit commitment or power flows in energy supply systems. For heat supply systems, however, it faces a relevant limitation: For them, energy yield depends on the output temperature, thus both quantities would have to be optimised simultaneously and the resulting problem is quadratic. As a...
Conference Paper
Full-text available
At KARA, the Karlsruhe Research Accelerator of the Karlsruhe Institute of Technology synchrotron, the so-called short-bunch operation mode allows the reduction of the bunch length down to a few picoseconds. The microbunching instability resulting from the high degree of longitudinal compression leads to fluctuations in the emitted terahertz radiati...
Presentation
Bei dem Vortrag handelt es sich um eine kurze Erläuterung, wie die Stadt Oldenburg durch die Gestaltung des Bebauungsplans Einfluss auf die Bebauung im Fliegerhorst Bauabschnitt 777F genommen hat. Im Weiteren wird die energetische Simulation für das Quartier beschrieben und gezeigt, dass die Sektorenkopplung entscheidend für die Flexibilisierung de...
Preprint
Full-text available
The planning and decision-making for a distributed energy supply concept in complex actor structures like in districts calls for the approach to be highly structured. Here, a strategy with strong use of energetic simulations is developed, the core elements are presented and research gaps are identified. The exemplary implementation is shown using t...
Preprint
Full-text available
The description of physical processes with many-particle systems is a key approach to the modeling of countless physical systems. In storage rings, where ultrarelativistic particles are agglomerated in dense bunches, the measurement of their phase-space distribution (PSD) is of paramount importance: at any time the PSD not only determines the compl...
Article
Full-text available
In recent and future synchrotron radiation facilities, relativistic electron bunches with increasingly high charge density are needed for producing brilliant light at various wavelengths, from X-rays to terahertz. In such conditions, interaction of electron bunches with their own emitted electromagnetic fields leads to instabilities and spontaneous...
Conference Paper
Full-text available
Short electron bunches in a storage ring are subject to complex longitudinal dynamics due to self-interaction with their own CSR. Above a particular threshold current, this leads to the formation of dynamically changing micro-structures within the bunch, generally known as the micro-bunching instability. The longitudinal dynamics of this phenomenon...
Conference Paper
Full-text available
The microbunching instability is a longitudinal collective instability which occurs for short electron bunches in a storage ring above a certain threshold current. The instability leads to a charge modulation in the longitudinal phase space. The resulting substructures on the longitudinal bunch profile vary over time and lead to fluctuations in the...
Preprint
Full-text available
In recent and future synchrotron radiation facilities, relativistic electron bunches with increasingly high charge density are needed for producing brilliant light at various wavelengths, from X-rays to terahertz. In such conditions, interaction of electrons bunches with their own emitted electromagnetic fields leads to instabilities and spontaneou...
Article
Full-text available
At KARA, the Karlsruhe Research Accelerator of the Karlsruhe Institute of Technology synchrotron, the so-called short-bunch operation mode allows the reduction of the bunch length down to a few picoseconds. The microbunching instability resulting from the high degree of longitudinal compression leads to fluctuations in the emitted terahertz radiati...
Article
Full-text available
The development of fast detection methods for comprehensive monitoring of electron bunches is a prerequisite to gain comprehensive control over the synchrotron emission in storage rings with their MHz repetition rate. Here, we present a proof-of-principle experiment with a detailed description of our implementation to detect the longitudinal electr...
Article
Full-text available
Electron accelerators and synchrotrons can be operated to provide short emission pulses due to longitudinally compressed or substructured electron bunches. Above a threshold current, the high charge density leads to the microbunching instability and the formation of substructures on the bunch shape. These time-varying substructures on bunches of pi...
Article
Full-text available
To understand and control dynamics in the longitudinal phase space, time-resolved measurements of different bunch parameters are required. For a reconstruction of this phase space, the detector systems have to be synchronized. This reconstruction can be used for example for studies of the microbunching instability which occurs if the interaction of...
Article
Synchrotrons and modern FEL light sources operate with bunch repetition rates in the MHz range. The profile of the electron beam inside the accelerator can be characterized with indirect experimental techniques where linear array detectors are employed to measure the emitted synchrotron radiation or the spectrum of a near-IR laser. To improve the p...
Preprint
The development of fast detection methods for comprehensive monitoring of electron bunches is a prerequisite to gain comprehensive control over the synchrontron emission in storage rings with their MHz repetition rate. Here, we present a proof-of-principle experiment with at detailed description of our implementation to detect the longitudinal elec...
Article
Full-text available
At the KIT storage ring KARA (KArlsruhe Research Accelerator), the momentum compaction factor can be reduced leading to natural bunch lengths in the ps range. Due to the high degree of longitudinal compression, the micro-bunching instability arises. During this longitudinal instability, the bunches emit bursts of intense coherent synchrotron radiat...
Article
Full-text available
Solving the Vlasov-Fokker-Planck equation is a well-tested approach to simulate dynamics of electron bunches self-interacting with their own wake-field. Typical implementations model the dynamics of a charge density in a damped harmonic oscillator, with a small perturbation due to collective effects. This description imposes some limits to the appl...
Preprint
At KARA, the KArlsruhe Research Accelerator of the KIT synchrotron, the so called short bunch operation mode allows the reduction of the bunch length down to a few picoseconds. The micro- bunching instability resulting from the high degree of longitudinal compression leads to fluctuations in the emitted THz radiation, referred to as bursting. For e...
Preprint
Solving the Vlasov-Fokker-Planck equation is a well-tested approach to simulate dynamics of electron bunches self-interacting with their own wake-field. Typical implementations model the dynamics of a charge density in a damped harmonic oscillator, with a small perturbation due to collective effects. This description imposes some limits to the appl...
Conference Paper
Full-text available
Solving the Vlasov-Fokker-Planck equation is a well-tested approach to simulate dynamics of electron bunches self-interacting with their own wake-field. Typical implementations model the dynamics of a charge density in a damped harmonic oscillator, with a small perturbation due to collective effects. This description imposes some limits to the appl...
Conference Paper
Full-text available
At the KIT storage ring KARA (KArlsruhe Research Accelerator), the momentum compaction factor can be reduced leading to natural bunch lengths in the ps range. Due to the high degree of longitudinal compression, the micro-bunching instability arises. During this longitudinal instability , the bunches emit bursts of intense coherent synchrotron radia...
Conference Paper
Full-text available
The operation of synchrotron light sources with short electron bunches increases the emitted coherent synchrotron radiation (CSR) power in the THz frequency range. However , the spatial compression leads to complex longitudinal dynamics, causing the formation of micro-structures in the longitudinal bunch profiles. The fast temporal variation and sm...
Conference Paper
Full-text available
The storage ring Karlsruhe Research Accelerator (KA-RA) at KIT operate in a wide energy range from 0.5 to 2.5 GeV. Different non-linear effects, in particular, residual octupole components of the magnetic field of the CATACT wiggler at high field level (2.5 T), proximity of the working point to a vertical sextupole resonance Qy=8/3 and weak couplin...
Conference Paper
Full-text available
High repetition rate diagnostics are required when detecting single-shot electro-optical profiles. The KIT storage ring KARA (Karlsruhe Research Accelerator) is the first and only storage ring that has a near-field electro-optical bunch-profile monitor in operation. By imprinting longitudinal electron bunch profiles onto chirped laser pulses, singl...
Conference Paper
Full-text available
Time-correlated single photon counting (TCSPC) is a versatile tool for various accelerator diagnostics aspects. Amongst others it allows a precise determination of the filling pattern. At the visible light diagnostics port at the Karl-sruhe Research Accelerator (KARA), the KIT storage ring, a Single-Photon Avalanche Diode (SPAD) in combination with...
Conference Paper
Full-text available
Measurements of the bunch current dependent synchronous phase shift are a standard method to characterize the impedance of a storage ring. To study this shift, different experimental approaches can be used. In this contribution , we first derive the phase shift caused by the impedance describing the emission of coherent synchrotron radiation (CSR)...
Conference Paper
Full-text available
While recent diffraction-limited storage rings provide bunches with transverse dimensions smaller than the wavelength of the observed synchrotron radiation, the bunch compression in the longitudinal plane is still challenging. The benefit would be single cycle pulses of coherent radiation with many orders of magnitude higher intensity. However, the...
Preprint
Electron accelerators and synchrotrons can be operated to provide short emission pulses due to longitudinally compressed or sub-structured electron bunches. Above a threshold current, the high charge density leads to the micro-bunching instability and the formation of sub-structures on the bunch shape. These time-varying sub-structures on bunches o...
Preprint
Time-resolved measurements of the energy spread, the longitudinal bunch profile together with studies of the emitted coherent synchrotron radiation allow investigations of the beam dynamics of synchrotron light sources. The simultaneous turn-by-turn measurement of these quantities requires a precise synchronization of the individual detector system...
Conference Paper
Full-text available
Accelerators with high bunch-repetition rates mandate high-throughput detector electronics to diagnose each individual bunch. KALYPSO with a 256-pixel detector line-array integrated in an fs laser-based electro-optical set-up allows longitudinal bunch profiling with sub-ps resolution as demonstrated at the storage ring ANKA for single-bunch mode op...
Conference Paper
Full-text available
For electron accelerators, electro-optical methods in the near-field have been shown to be a powerful tool to detect longitudinal bunch profiles. In 2013, we demonstrated for the first time, electro-optical bunch profile measurements in a storage ring at the accelerator test facility and synchrotron light source ANKA at the Karlsruhe Institute of T...
Conference Paper
Full-text available
The test facility and synchrotron radiation source ANKA at the Karlsruhe Institute of Technology (KIT) in Karlsruhe, Germany, can be operated in a short-pulse mode. Above a threshold current, the high charge density leads to microwave instabilities and the formation of sub-structures. These time-varying sub-structures on bunches of picosecond durat...
Conference Paper
Full-text available
The test facility and synchrotron light source ANKA at the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and can generate brilliant coherent synchrotron radiation (CSR) in the THz range employing a dedicated bunch length-reducing optic at 1.3 GeV beam energy. The high degree of spatial compression leads to...
Conference Paper
Full-text available
Recently, a new setup for measuring the beam energy spread has been commissioned at the ANKA storage ring at the Karlsruhe Institute of Technology. This setup is based on a fast-gated intensified camera and detects the horizontal profiles of individual bunches in a multi-bunch environment on a single-turn base. As the radiation source point is loca...
Preprint
Full-text available
The numerical solution of the Vlasov-Fokker-Planck equation is a well established method to simulate the dynamics, including the self-interaction with its own wake field, of an electron bunch in a storage ring. In this paper we present Inovesa, a modularly extensible program that uses OpenCL to massively parallelize the computation. It allows a sta...
Conference Paper
We developed a fast linear array detector to improve the acquisition rate and the resolution of Electro-Optical Spectral Decoding (EOSD) experimental setups currently installed at several light sources. The system consists of a detector board, an FPGA readout board and a high-throughput data link. InGaAs or Si sensors are used to detect near-infrar...
Conference Paper
Full-text available
In order to simulate the dynamics of an electron bunch due to the self-interaction with its own coherent synchrotron radiation it is a well established method to numerically solve the Vlasov-Fokker-Planck equation. In this paper we present a modularly extensible program that uses OpenCL to massively parallelize the computation, allowing a standard...
Article
Full-text available
Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal dynamics of the electron bunches, which can be probed studying the fluctuations in the emitted terahertz radiatio...
Conference Paper
Full-text available
Interferometry is the quasi-standard for spectral measurements in the THz-and IR-range. The frequency resolution, however, is limited by the travel range of the interferometer mirrors. Therefore, a resolution in the low megahertz range would require interferometer arms of about 100 m. As an alternative, heterodyne measurements provide a resolution...
Conference Paper
Full-text available
Coherent ultrashort THz pulses induced by a laser-electron interaction are routinely produced and observed at DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University. The turn-by-turn evolution of the radiation spectrum is known to shift to the sub-THz regime after the initial laser-electron interaction. Recently, an ultraf...
Conference Paper
Full-text available
ANKA, the synchrotron light source of the Karlsruhe I