Workshop on Laser Fusion Research Opportunities at FAIR

SB Lecture Hall (GSI)

SB Lecture Hall


Planckstr. 1 64291 Darmstadt

The HED@FAIR collaboration welcomes the HED physics community to a two-day workshop on laser fusion research opportunities at FAIR on June 20th and 21st, 2024, at GSI Darmstadt’s main auditorium.

With the recent milestone achieved at the National Ignition Facility in the USA in inertial confinement fusion, the German government has changed its position significantly on laser-driven fusion and now fully endorses research on this subject. The HED@FAIR collaboration has expressed interest in adding laser fusion research to its research portfolio because of the many synergies between the planned activities of the collaboration at FAIR and the individual scientific interests of the collaboration partners.

The current proposal is to speed up the installation of a multi-kilojoule multi-beam laser facility on the FAIR campus in connection with the APPA cave to support, among others, laser fusion research until the compression facility becomes available. Importantly, this facility, which could be built in collaboration with the start-up company Focused Energy GmbH, will be open to academic access on a proposal-merit basis. This ensures that the HED physics community has a fair and equal opportunity to contribute to and benefit from this research.

Topics for the workshop are to help define the facility’s scientific requirements for:

  • Laser-plasma instability studies
  • Hydrodynamic instabilities and compression studies in planar geometry
  • Code development and benchmarking needs
  • Fast ignition
  • X-ray diagnostics
  • Material studies: foam, EOS
  • Laser systems

The workshop will be coupled with a visit of the FAIR facility.

Workshop organizers: V. Bagnoud, M. Roth, P. Neumayer, K. Schoenberg, D. Kraus


    • 09:00 10:15
      Existing ICF capabilities at GSI and future possibilities at FAIR SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
      • 09:00
        Welcome to GSI and introduction 15m
        Speaker: Vincent Bagnoud (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
      • 09:15
        PHELIX current capabilities & possible upgrades 30m

        We will give a brief overview of the currently available capabilities of PHELIX and the ongoing developments at the different experimental areas, with the main focus being on fusion-relevant experiments and upgrades.
        We will present our recent progress on the development of a temporally-incoherent broadband nanosecond oscillator, our development of a standalone backlighter laser useable for preplasma diagnostics and the upgrade of our main amplifier in order to increase the repetition rate of PHELIX. These improvements will make PHELIX an ideal test bench for LPI experiments and fusion relative research in general.
        Additionally, we will give a brief update on the recent developments at the LIGHT beamline to extend the fundamental research on energy loss measurements in plasmas, which are crucial for inertial confinement fusion and the progress on fusion-related material research.

        Speaker: Johannes Hornung (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
      • 09:45
        Concept for an IFC research capability at FAIR 30m

        At FAIR, the HED@FAIR collaboration will exploit the target station in the so-called APPA cave, where unprecedented high intensity ion pulses will be available to create WDM states of matter on mesoscopic scales. To probe such exotic states of matter, a high-energy laser facility has always been planned.
        A design study has been made to increase the inital planned capability to a 4-beam kilojoule laser facilty, in order to support ICF research. The proposed implementation will be described as well as areas of possible collaborations for technological developments.

        Speaker: Vincent Bagnoud (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
    • 10:15 10:40
      Coffee Break 25m SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
    • 10:40 12:30
      IFE Research SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
      • 10:40
        Experiments on equation of state and microphysics of IFE ablator materials 25m

        The first compression step, usually a shock to pressures of several Mbars, sets the "adiabat" for typical ICF implosions and thus the maximum compression of the DT fuel. In this regime, i.e., the low-temperature end of warm dense matter, both equation of state and microphysics are poorly understood. At the same time, small inhomogeneities in this early stage can be magnified by hydro instabilities during later stages to sufficient amplitude to mix substantial amounts of ablator material into the fuel. Efficient IFE designs will require some level of understanding of equation of state and microphysics of cheap ablabtor materials as basis for point designs in the Mbar to Gbar range. Moreover, for informed discussion and selection of potential power plant designs, such understanding needs to be openly available. State-of-the-art experimental facilities and exploiting new simulation and theory capabilities, together with a lively academic community, will allow to establish such a framework.

        Speaker: Dominik Kraus (HZDR)
      • 11:05
        A dedicated station for Ion stopping power studies in extreme states of plasmas 20m
        Speaker: luca volpe (ETSIAE Universidad Politecnica de Madrid)
      • 11:25
        Past, present and future experiments at GSI on energy loss in plasma 20m

        Measuring energy loss of ions in plasma is a long running research topic at GSI. While the Unilac ion beam with his intense and only a few ns long microbunches serves as an excellent probe beam, different pump schemes for the creation of an appropriate plasma were investigated. Starting with gas discharge plasma, over laser driven plasma by heating foils directly or via conversion of laser light into x-rays in a hohlraum, plasmas with different densities and temperatures were investigated. With the development of the LIGHT beam line, where the PHELIX laser and a rf cavity are used to deliver extremely intense and sub-ns long ion pulses, a new tool is available at present for more precise measurements. Finally, as FAIR is approaching and the ion beam intensities at the experimental cave HHT behind the SIS18 synchrotron are increasing, new schemes for the investigation of ion energy deposition in heavy ion driven WDM are evaluated.

        Speaker: Abel Blazevic (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
      • 11:45
        Feasibility study for proton FI via hole boring acceleration from foam targets 25m
        Speaker: Daniel Seipt (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
      • 12:10
        Developments for laser-driven polarized fusion 20m

        We introduce our developments on polarized fusion and the achievements in the last few years, i.e., the first experiment with a polarized $^3\!$He target at PHELIX providing evidence of $^3\!$He nuclear polarization persistence after laser-plasma ion acceleration to MeV energies [1] and a new method to enhance nuclear polarization in a so-called Sona-transition unit, which has the potential to produce the polarized fuel for fusion reactors [2].

        During the next ten years, we plan to continue our studies of spin dynamics in plasmas at PHELIX with a new $^3\!$He gas polarizer, which is movable and can produce fresh polarized $^3\!$He gas locally at GSI. It is also proposed to employ the SEPPL probe beam for the measurement of the transient magnetic field as a new diagnostic approach for these plasmas. This project would substantially profit from the planned laser facility at GSI/FAIR with increased repetition rate. As a long-term vision, our activity will focus on the demonstration of laser-induced D+$^3\!$He or D+T polarized fusion, which has the potential to enhance fusion reactor efficiencies by about 75% and to facilitate the neutron management through non-isotropic neutron emission [3].

        [1] First evidence of nuclear polarization effects in a laser-induced $^3\!$He fusion plasma.
        doi: 10.48550/arXiv.2310.04184
        [2] A universal method to generate hyperpolarisation in beams and samples.
        doi: 10.48550/arXiv.2311.05976
        [3] A research program to measure the lifetime of spin polarized fuel.
        Front. Phys. 12:1355212; doi: 10.3389/fphy.2024.1355212

        Speaker: Dr Chuan Zheng (Heinrich-Heine-Universität Düsseldorf)
    • 12:30 13:30
      Lunch Break (GSI- Cantine) 1h Cantine



    • 13:30 15:40
      IFE Research needs and developments SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
      • 13:30
        Implosion Target Designs with Mitigation of Laser-Plasma Instabilities for Inertial Fusion Energy 25m

        The company Focused Energy develops target designs for an inertial fusion pilot plant (FPP) within the DOE public-private partnership program. For the direct drive compression of the target shell both the second and the third harmonic of neodymium glass laser (2ω and 3ω) are considered. Target point designs based on 1-D radiation hydrodynamic simulations are presented. While 2ω light relaxes the requirements for the laser and the reactor, it complicates the target physics. The onset of laser plasma instability (LPI) and their growth rates scale with the laser wavelength and the plasma parameters. The longer wavelength at 2ω and a longer density scale length L_n at the quarter critical density for a 2ω design compared to a 3ω design, reduce the laser intensity thresholds for the onset of deleterious instabilities such as stimulated Raman scattering (SRS) and two-plasmon decay (TPD). Therefore, the characterization of LPI at ignition relevant plasma conditions and its mitigation are of high priority. We assess LPI and its mitigation with spectrally broad bandwidth laser light through simulations for FPP conditions (L_n ~ 600 μm and T_e ~ 4 keV for our 2ω design). Simulation results are presented to quantify SRS thresholds and to assess the broad bandwidth requirement for our target designs. An initial assessment of the effect of cross-beam energy transfer (CBET) on the implosions with narrow bandwidth beams will be presented. LPI experiments at 2ω are ongoing to benchmark the simulations tools at sub-scale in terms of predicting the onset and the growth of LPI.

        Speaker: Wolfgang Theobald (Focused Energy)
      • 13:55
        Fusing simulation and data analysis for laser fusion research opportunities at FAIR 25m

        Advancing our understanding of laser fusion by basic research has proven to be driven by closely interlinking modeling of laser fusion with experimental observations. This is mainly due to the extreme scales in space and time and the high nonlinearities present in matter under extreme conditions, for which diagnostics ranging from the atomic to the full material scale are needed and augmetation of measured data with simulation data has driven our understanding of laser matter interaction at extreme conditions.
        FAIR provides unique facilities both for beam driven and laser driven fusion research. It also provides unique facilities for data management, analysis and simulation.
        In this presentation I want to focus on proposing data-driven research for laser fusion at FAIR comprising of three pillars. The first is the provision of experimental data relevant for fusion applications to the community. The second is enabling systematic parameter exploration and virtual experiments of laser matter interaction, which requires multi-physics, multi-scale modeling at large computing scales. The third is model-informed experiments, in which exploration of operational parameters for experiments and analysis of experimental data are informed by modeling while simulations are informed by experimental data, thus closing the loop between experiments and simulations.
        The proposal would foster laser fusion research by the insight FAIR's unique data sets can provide. It is clear that this would fit well into an initiatve beyond FAIR and thus this talk will refer to existing projects that could start off such an initiative and propose to fill the missing gaps by a dedicated initiative.

        Speaker: Michael Bussmann (Helmholtz-Zentrum Dresden - Rossendorf)
      • 14:20
        Ab initio calculation of thermophysical properties for ICF plasmas 20m

        The thermophysical properties of ICF plasmas (e.g. EOS data, opacity, conductivities, stopping power) are needed to assess and optimize existing compression scenarios via rad-hydro or PIC simulations and to evaluate corresponding experiments. Usually, relatively simple plasma models like Spitzer's transport theory for fully ionized plasmas and wide-range EOS data tables such as SESAME or LEOS are used for that purpose. Major improvements in understanding the underlying microphysics are expected by calculating the thermophysical properties of ICF plasmas via ab-initio simulations. In order to tackle the corresponding computational challenges, a joint effort of theory, simulations and data science is needed.

        Speaker: Ronald Redmer (University of Rostock)
      • 14:40
        Inertial Fusion Energy: Opportunities and Challenges of the Laser Technology in the Journey Towards Scientific Risk Mitigation 25m

        Inertial Fusion Energy (IFE) represents a promising pathway towards achieving sustainable and nearly limitless clean energy. Central to the IFE concept is the use of powerful laser technology to initiate nuclear fusion reactions. This presentation delves into the opportunities and challenges associated with laser technology in the context of IFE, highlighting its pivotal role in the journey towards scientific risk mitigation. We will explore Focused Energy´s facility roadmap in parallel to its laser systems development roadmap, which also encompasses near-term applications such as laser-driven radiation sources. The discussion will also address the technical and logistical hurdles, such as stress on supply chain and required industrial eco-system towards mass manufacturing of thousands of kJ-class laser systems.

        Speaker: Dr Clément Paradis (Focused Energy GmbH)
      • 15:05
        Adaptive Laser Architecture - Unlocking IFE with Next-Generation Laser Control 20m

        Inertial Fusion Energy (IFE) demands exceptional consistency in laser beam quality to reliably achieve ignition. Paired with the need for high repetition rates at high energies, this requirement becomes a prime challenge in IFE laser technology and has not yet been fully addressed. This talk introduces Adaptive Laser Architecture (ALA): a paradigm shift in active laser beam control. ALA moves beyond traditional localized control methods, adopting a holistic, integrated framework that enables automated real-time control and precise management of high-energy laser arrays. This innovative approach not only paves the way for practical IFE applications but also redefines standards in high-energy, high-intensity laser technology.
        The presentation will outline the ALA concept, discuss associated challenges, and detail a pathway for its continuous development through the ALADIN project, aiming to implement this transformative solution for IFE.

        Speaker: Jonas Benjamin Ohland (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
      • 15:25
        Discussion round on laser technologies 15m
    • 15:40 16:00
      Coffee Break 20m SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
    • 16:00 18:05
      IFE and materials research SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
      • 16:00
        Kinetic modeling of laser-plasma instabilities in directly driven fusion capsules 25m

        The success of inertial fusion energy (IFE) hinges on the ability to couple high-energy lasers efficiently to fusion capsules to compress the hydrogenic fuel to the required densities. One of the major elements of risk in IFE is the possibility of exciting laser-plasma instabilities (LPI), which can rob energy from the laser beams, degrade implosion symmetry, and produce energetic electrons that can preheat the fuel. Complicating our understanding of LPI is that such instabilities are often kinetic, meaning that they involve in a fundamental way the complicated interaction of waves and particles (electrons, ions) in the coronal plasma. Fortunately, recent advances in kinetic plasma modeling using state-of-the-art tools such as the Open Source VPIC* code, enable modeling and exploration of the sensitivities of LPI on laser and plasma conditions in IFE relevant settings and assessment of the efficacy of proposed LPI mitigation approaches. Preliminary results of these studies and implications for proposed laser facilities will be presented in this talk. Moreover, these modeling tools allow us to evaluate other relevant physics processes, such as the interaction of ultra-high-power lasers with targets, as in fast-ignition IFE concepts.

        Speaker: Juan Fernandez (Los Alamos National Laboratory)
      • 16:25
        Importance of stimulated Raman side-scattering in Direct-Drive experiments 25m

        Direct-Drive Ignition (DD) is an Inertial Confinement Fusion (ICF) scheme in which a fuel target is compressed and ignited by direct laser irradiation. Despite preliminary results anticipating the predominance of Two-Plasmon Decay, recent experiments have evidenced the dominant role of the Stimulated Raman Scattering (SRS). This three-wave coupling leads to the scattering of the incident energy away from the interaction region and the generation of a hot electron population that can preheat the fuel core. Under such conditions, SRS can develop in multiple geometries, such as the standard back-scattering (back-SRS) and the more elusive side-scattering (side-SRS). However, the inherent complexity of the side-scattering geometry is strongly limiting experimental characterization, preventing to obtain a side-SRS comprehensive understanding.

        Recent measurements, obtained during experimental campaigns at the Shenguang-II Upgrade and Vulcan laser facilities, have implemented a new diagnostic method specifically designed to measure SRS over a wide range of angles. Direct comparison with backscattering measurement have evidenced a regime dominated by side-SRS at moderate laser intensity. Thus, these experiments provide an ideal platform to characterize side-SRS instability. Parametric scans have been conducted to observe the dependence of side-SRS on the incident laser energy, laser polarization and plasma density scale length. Preliminary analysis of the data along with the implications for IFE design will be discussed during this presentation.

        Speaker: Kevin Glize (STFC/CLF)
      • 16:50
        Laser-driven free electron X-ray sources for plasma backlighting 25m

        Fusion-relevant experiments at FAIR will require sophisticated probing equipment to make optimum use of valuable beam time. I will try to make the case for implementing a moderate energy (<10J) ultrashort-pulse laser arm, pumped by a small amount of energy from the existing or planned ns heater beams, in order to drive a high-current laser wakefield electron source. Its beams have exceptionally high phase space density, making them ideal free-electron X-ray sources. Depending on the target's electron temperature, two candidate X-ray generation mechanisms will be investigated: Betatron emission and Thomson/Compton backscattering. Both have their specific strengths and weaknesses for probing at lower (~10 keV) and higher (~100 keV), albeit overlapping, energy regimes. I will try to map out their properties based on simple scaling laws and experimental results, in order to lay the foundations for a point design for a FAIR probing system. Finally, I will briefly discuss the possibility for multimode probing using both electrons and X-rays.

        Speaker: Stefan Karsch (Universität München)
      • 17:15
        GSI MAT ion facilities for Fusion Materials 25m

        Neutron irradiation of fusion materials is a limiting factor in the turnaround time to design and test novel material solutions due to high neutron-induced activation and availability of suitable sources. In comparison, irradiation with swift heavy ions at GSI and FAIR can produce peak radiation doses relevant for first wall materials within a few accelerator days. The Materials Research Department of GSI operates several user beamlines with a large flexibility of beam parameters and ion species for high dose irradiation in conjunction with possibilities to perform on-line, in-situ and ex-situ experiments to characterize irradiated materials.

        Speaker: Pascal Simon (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
      • 17:40
        Thermo-mechanical characterization of materials for fusion applications 25m

        Fusion materials operate under intense radiation damage and thermo-mechanical loads. We present current and planned facilities at Materials Research Department at GSI and FAIR for characterization of materials performance with radiation damage and thermo-mechanical fatigue evolution. Different in situ set ups for monitoring the dynamical response of different targets, their radiation induced dimensional changes as well as facilities for post-irradiation characterization of mechanical and thermal properties degradation are described.

        Speaker: Marilena Tomut (GSI Helmholtzzentrum, Darmstadt;Institute of Materials Physics, WWU, Münster)
    • 19:00 22:00
      Dinner (GSI) 3h SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
    • 09:00 10:45
      Landscape Analysis SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
      • 09:00
        High energy density physic studies on high energy lasers 25m

        something about HIPER+

        Speaker: Dr Sébastien Le Pape (LULI, Ecole Polytechnique, France)
      • 09:25
        Laser Plasma Physics fur Fusion Science at CLPU 25m

        Laser Plasma Physics fur Fusion Science at CLPU**

        M. Ehret^, J. A. Pérez-Hernández, C. Salgado,
        J. I. Apiñaniz, C. Mendez, I.-M. Vladisvlevici,
        and G. Gatti, L. Volpe, Ma. D. Rodríguez Fías

        Centro de Láseres Pulsados, Salamanca, Spain


        We present results from our investigation of electromagnetic pulses with relevance for ion-fast-ignition [1] at the ICTS unique infrastructure Centro de Láseres Pulsados (Villamaoyor, Spain). We will give an overview of related metrology for laser plasma experiments, laser sources, and laser based secondary sources [2,3].

        With respect to future activities, we will (i) summarize the possible lanes towards our increased involvement in exploratory fusion science; and (ii) give a perspective on the interest of the Spanish community.

        Keywords: high power laser, high energy density, high repetition rate, secondary sources

        [1] M. Ehret et al., Physics of Plasmas 30, 013105 (2023)
        [2] M. Ehret et al., Plasma Physics and Controlled Fusion 66, 045003 (2024)
        [3] M. Ehret et al., accepted at HPLSE (2024)

        Speaker: Dr Michael Ehret (CLPU)
      • 09:50
        Report about recent workshop: Tackling Some Inertial Fusion Energy Challenges at the European XFEL. (11 - 12 June 2024) 20m

        This talk will summarize the recently conducted workshop at the European XFEL.
        The HED-HIBEF activities at European XFEL would be a natural basis for a fusion hub, e.g., by installing a new dedicated IFE-Research Instrument (IFE-RI) at this facility and building on its international community.

        This workshop aimed to discuss the general role of XFELs towards an IFE power plant and identify both IFE-relevant activities that can be pursued at the existing HED-HIBEF instrument and flagship experiments with a future IFE-RI, ideally providing multi-kJ, multi-beam long pulse and short pulse drive lasers. The topics include XFEL-based diagnostics of IFE target physics, microscopic x-ray imaging and diffraction of dynamic radiation damage cascades of fusion reactor walls, XFEL-based diagnostics of IFE plasmas compatible with sub-scale and full-scale IFE facilities, laser technology required for IFE-RI, and finally theory & simulation developments required to support an IFE program at EuXFEL.

        Speaker: Ulf Zastrau (European XFEL)
      • 10:10
        Gaps in the theoretical support for ICF experiments 15m

        The design, analysis and interpretation of HEDP experiments relies heavy on simulation tool such as radiation hydro-dynamics. While there are a number of codes available, the quality of the input data for these codes is questionable. The contribution will review the situation and proposes a programme to improve this situation including suggestions for supporting experiments.

        Speaker: Dirk Gericke (University of Warwick)
      • 10:25
        Discussion 20m
    • 10:45 11:15
      Coffee Break 30m SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
    • 11:15 12:35
      Fussion hub in the state of Rhein-Main Area SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt
      • 11:15
        Towards a German Laser Fusion Hub 30m

        As an US/German Fusion startup FE has a strong commitment to establish a fusion HUB in Germany.
        For this, FE plans to increase its presence in and around Darmstadt by building the target and laser development laboratory at its site and further expand the activities partnering with RWE for laser-driven radiation sources. Moreover, FE is working on a roadmap and conceptual design for an integrated test facility that will leverage all required technical components and procedures to the required TRL for building a power plant. This will be done in close collaboration with industrial and academic partners in the local area and throughout Europe.

        Speaker: Prof. Markus Roth (Focused Energy GmbH)
      • 11:45
        Vision of the HED@FAIR collaboration 20m
        Speaker: Dr Kurt Schoenberg (HED@FAIR COLLABORATION)
      • 12:05
        Discussion: planning the next steps 30m
    • 12:35 14:00
      Lunch Break (GSI- Cantine) 1h 25m Cantine



    • 14:00 16:30
      FAIR Site Visit SB Lecture Hall

      SB Lecture Hall


      Planckstr. 1 64291 Darmstadt