Contact
Photo: HZDR/André Wirsig
Dr. Josefine Metzkes-Ng
Junior Research Group Leader "Application-oriented Laser-plasma Accelerators"
Laser Particle Acceleration
j.metzkes-ng
hzdr.de
Phone: +49 351 260 2158
Prof. Dr. Ulrich Schramm
Director Institute for Radiation Physics and Head Laser Particle Acceleration Division
u.schrammhzdr.de
Phone: +49 351 260 2471
Application-Oriented Laser Particle Acceleration
Our Mission
Our goal is to build a stable, application-ready laser particle accelerator based on a high-power petawatt laser. This approach enables ion beam acceleration over extremely short distances, and we are working to make it reliable and reproducible.
In addition to the acceleration itself, we focus intensively on controlled beam transport as well as tailored detector and dosimetry systems. Together, these components form an integrated system for demanding application experiments.
As an interface between physics, technology, and application, we work closely with internal and external partners and always welcome committed students.
Our Research Focus
The image below illustrates our main topics of research. Additional information appears when hovering with the mouse.
Application-oriented research with laser-driven accelerators: acceleration, transport, detection, and application (from left to right)
Image: HZDR / Juniks
Laser Particle Acceleration
In laser-driven ion acceleration, extraordinarily high accelerating fields (~MV/µm) are generated in a plasma over extremely short distances (~µm). In principle, this enables very compact particle accelerators. At the same time, ultrashort, intensely pulsed ion beams with unique properties are produced, opening up new experimental avenues. Laser ion accelerators are therefore considered a promising technology for applications in materials research, nuclear physics, and potentially in medicine.
At the same time, this technology comes with significant challenges. Laser-accelerated ion beams typically exhibit broad energy spectra and large divergence angles as well as strong shot-to-shot fluctuations. For applications, however, stable, reproducible, and well-defined beam parameters are required. In addition, there are demands on the efficiency, repetition rate, and long-term stability of the laser systems.
Our goal is to turn a fascinating physical demonstrator into a reliable, application-ready accelerator. A detailed understanding of the underlying acceleration processes is crucial for this. To this end, we work closely with the research groups for Laser Ion Acceleration and Computational Radiation Physics. The high-intensity laser that drives our experiments is the PEnELOPE laser. Developed at HZDR, it is a fully direct diode-pumped laser system with particularly high efficiency.
Beam Transport with High-Field Magnets
Integrating a laser-driven ion accelerator into a robust, application-ready system places high demands on beam transport. The extraordinary beam parameters require new methods for beam guidance.
We adapt established technologies from the Dresden High Magnetic Field Laboratory and use pulsed high-field magnets to capture the laser-accelerated beams, perform energy selection, and transport them to the irradiation site. The focus is not on field strength records, but on reliable usability in the demanding laser-plasma environment.
Our high-field magnets are powered by compact high-current pulse generators. This combination has been successfully used in our laboratories for over a decade. We are currently developing the next generation of this technology, with a particular focus on repetitive operation. Together with the Chair of Power Electronics at TU Dresden, we have developed the first pulsed current driver capable of powering high-field magnets at a repetition rate of 1 Hz.
Kroll et al.: Tumour irradiation in mice with a laser-accelerated proton beam. Nature Physics (2022)
Detector Development and Dosimetry
Even after successful beam capture and transport, the parameters of laser-accelerated particle beams remain so unusual that conventional detector systems often reach their limits. For this reason, we develop a wide range of specialized detectors for our laser-driven beams.
A particular focus lies on online detectors that allow immediate measurement of beam parameters during the experiment. The goal is to characterize the beam already close to the source, continuously monitor its transport, and provide highly precise dosimetry at the irradiation site.
Our detectors are based mainly on scintillators, i.e. materials that emit light when exposed to radiation. In addition, diamond detectors are also used as time-of-flight spectrometers.
Application Studies
The central goal of our research is to make the exceptional properties of laser-accelerated particle beams usable for concrete applications. A key focus is radiation-based cancer research.
The so-called FLASH effect is of particular interest here. In the context of cancer research, it describes the phenomenon that delivering the radiation dose within a very short time at ultra-high dose rates leads to reduced healthy tissue damage, while tumor tissue is affected to a similar extent. Although initial results are promising, the underlying underlying mechanisms are not yet fully understood.
The exceptionally high instantaneous dose rates of laser-driven particle beams offer a unique opportunity to investigate these mechanisms systematically. We carry out corresponding radiobiological experiments in close collaboration with the research group for Ultra-High Dose-Rate Radiobiology as well as with the National Center for Radiation Research in Oncology – OncoRay.
In addition, our research activities cover further fields, including laser-driven neutron sources for nuclear physics experiments, laser-based inertial fusion, and new approaches in detector physics.
Through the continuous development of our technologies and an increasing focus on automation, we are creating the prerequisites for even more flexible and powerful application experiments in the future.
Kroll et al.: Tumour irradiation in mice with a laser-accelerated proton beam. Nature Physics (2022)
Laboratories and Facilities
Laboratory for Application-Oriented Laser Particle Acceleration
The setup of the laboratory for our application-oriented experiments in laser-driven particle acceleration is largely complete.
In this laboratory, we investigate the generation and control of laser-accelerated particle beams as well as their use in first application experiments. The experiments take place in a vacuum chamber in which laser-plasma interactions can be studied under controlled conditions. Various target systems, beam-guiding optics, and laser and particle diagnostics enable flexible adaptation of the experimental setup to adress different research questions.
A particular focus lies on the integration of beam transport, diagnostics, and dosimetry in order to characterize laser-accelerated particle beams as comprehensively as possible and make them usable for irradiation experiments. Thanks to the modular architecture of the laboratory, new components and diagnostic systems can be continuously integrated into the experimental setup.
As the laboratory is still under development, it offers students the opportunity to help shape a complex experimental environment from the outset—ranging from hands-on work on setup and diagnostics to contributions in programming, automation, and control.
Development Laboratory for Pulse Generators and High-Field Magnets
In addition to our laser laboratories, we operate a development laboratory for pulsed high-field magnets and the associated high-current pulse generators.
In this laboratory, we work on experiments where high voltages and extreme currents come together: our systems reach voltages of up to 24 kV, currents of around 20 kA, and generate pulsed magnetic fields of up to 40 T. Such parameters place high demands on the mechanical stability, electrical insulation, and thermal resilience of the components used.
A current focus of our work is the development of magnet coils that can be operated over longer periods at high repetition rates (up to 1 Hz). While classical high-field magnets usually generate only single pulses, our goal is to develop robust coil designs that can be operated repeatedly. To this end, efficient cooling strategies in particular are being developed and tested experimentally.
The laboratory provides students with technical research opportunities, including measurements and development of pulse generators and magnet systems, as well as programming experimental control software.
Team
“Application-Oriented Laser Particle Acceleration” Team
| Josefine Metzkes-Ng | Junior Research Group Leader |
| Florian Kroll | Scientist, Pulsed Beam Transport |
| Joshua Schilz | PhD Student, Detector Development and Characterization |
Alumni
| Maximilian Müller | Master's thesis – Optimization of experimental proton beam parameters based on a TangoControl-based experimental setup |
| Radka Štefaníková | Doctoral thesis – Investigating Electron Dynamics in Ultra-Short Relativistic Laser-Solid Interaction – Coming soon... |
| Angela Corvino | Master's thesis – MiniSCIDOM: a scintillator-based tomograph for online reconstruction of millimeter-scale dose distributions |
| Marvin Reimold | Doctoral thesis – Beam monitoring and dosimetry for ultra-high dose rate radiobiology at laser-driven proton sources – Read → |
| Florian-Emanuel Brack | Doctoral thesis – Dose formation using a pulsed high-field solenoid beamline for radiobiological in vivo studies at a laser-driven proton source – Read → |
Publications
An overview of all publications to which the research group Application-Oriented Laser Particle Acceleration has contributed can be found here.
