MAT Collaboration Meeting 2026

Over the past three decades, interest in nanoporous structures—including
single nanopores and nanoporous membranes—has grown enormously. Nanopores have
become powerful platforms for fabricating biomimetic channels, developing
model systems for exploring new nanoscale phenomena, and creating single-
molecule biosensors. Nanopores enabled DNA sequencing and progress has been
made towards protein sequencing. In the talk I will focus on the pioneering
role track-etched membranes played in the design and preparation of bio-
inspired ionic diodes, transistors, biomimetic voltage-gated channels, and
single-molecule sensors. I will describe experiments with polymer track-etched
membranes that led to the discovery of surface-charge regulated transport. The
talk will also include the newest results on using track-etched nanopores as
dynamic ionic memristors that mimic memory processes in the human brain.

Nanofluidic memristors have emerged as promising substrates in neuromorphic computing applications due to their programable conductance memory states that are reminiscent of the brain synapses. We explore different options for the modulation of the conductance of track-etched conical nanopores by programming series of rectangular voltage pulses of different characteristics: amplitude, duration, and frequency. The resulting conductance states enables short-term memory and allow the implementation of learning procedures through potentiation (connection strengthening) and depression (connection weakening) effects, which can be further characterized by impedance spectroscopy measurements. Also, the nanofluidic system can exhibit negative differential resistance (NDR) phenomena due to salt precipitation, providing rich nonlinear dynamics in signal processing tasks. The memory features, together with nonlinear dynamics, allow the design of electrochemical networks of nanofluidic memristors that can provide operational procedures to implement both logical responses and reservoir computing algorithms using different voltage signals as inputs.

Over the past years, our group has explored the use of bioinspired solid-state nanochannels and nanofluidic architectures as versatile platforms for controlling ionic transport at the nanoscale. Inspired by the remarkable transport and gating mechanisms found in biological ion channels, our research has focused on understanding how confinement, surface chemistry, molecular recognition, and material architecture can be combined to impart functionality to artificial nanofluidic systems.

In this talk, an overview of several research directions developed within the group over the last few years will be presented, illustrating the evolution from fundamental studies of ion transport and molecular interactions under nanoconfinement toward increasingly complex and functional nanofluidic architectures. Particular attention will be given to chemically responsive nanochannels, where specific molecular interactions can be translated into changes in ionic transport and rectification, providing biomimetic approaches for chemical and biological sensing.

The talk will then highlight different strategies developed to dynamically control ionic transport, including electrochemically responsive interfaces and nanoprecipitation-based processes capable of modifying the internal transport environment of nanochannels. These approaches demonstrate how transient or reversible changes within nanoconfined spaces can give rise to nonlinear, hysteretic, and memory-like transport responses. In parallel, the incorporation of metal–organic frameworks (MOFs) into solid-state nanochannels has enabled the development of hierarchical heterostructures, in which the combination of nanochannel and nanoporous MOF length scales provides new opportunities to regulate ion transport and access distinct transport regimes.

Nanofluidic membranes can be used to harvest energy from salinity gradients, and bullet-shaped nanochannels offer promising characteristics, as their asymmetric geometry enhances power output relative to other nanochannel shapes [1]. For practical applications, however, energy conversion must be scaled from individual nanochannels to membranes containing large number of pores. In this transition, pore density and pore-to-pore interactions can strongly influence the response and overall energy conversion performance [2,3].

In this work, we investigate salinity-gradient energy conversion in track-etched, bullet-shaped nanochannels in polyethylene terephthalate (PET), with particular emphasis on the low-fluence regime, and focusing on the relationship between single-pore and multiporous membrane behavior. Single nanochannels are first characterized under different salinity gradients and pH to identify favorable operating conditions. Membranes with systematically varied pore densities are then investigated to assess how energy conversion performance scales with pore density.

Our results provide insight into the transition from single-pore to multiporous membrane behavior in osmotic energy harvesting and help identify key parameters for the development of scalable nanofluidic membranes for this application.

References
[1] G. Laucirica et al., Shape matters: Enhanced osmotic energy harvesting in bullet-shaped nanochannels, Nano Energy 71, 104612 (2020).
[2] J. Su et al., Anomalous Pore-Density Dependence in Nanofluidic Osmotic Power Generation, Chin. J. Chem. 36, 417–420 (2018).
[3] Z. S. Siwy, M. L. Bruening and S. Howorka, Nanopores: synergy from DNA sequencing to industrial filtration – small holes with big impact, Chem. Soc. Rev. 52, 1983–1994 (2023).

Swift heavy ions deposit enormous electronic energy densities in solids, leading to the formation of latent ion tracks that provide a unique platform for investigating radiation–matter interactions under extreme conditions. Beyond their fundamental scientific significance, ion tracks have emerged as an enabling tool for the fabrication of nanoporous membranes, nanostructures, and advanced functional devices. As one of the major heavy-ion accelerator facilities in Asia, the Heavy Ion Research Facility in Lanzhou (HIRFL) has served as a versatile platform for ion-track research over the past decades. Leveraging the capabilities of HIRFL, extensive efforts have been devoted to both the fundamental understanding of ion-track formation and the development of interdisciplinary applications.

In this presentation, recent ion-track research activities at HIRFL will be reviewed, covering fundamental investigations of track formation and evolution, characterization, transport properties of angstrom channels, and the development of ion-track-enabled functional materials. Emphasis will be placed on the ion-track membranes and functional materials. The integration of ion-track technologies with materials science, optical, and mechanical research will be discussed, illustrating the expanding role of heavy-ion accelerators in fostering interdisciplinary innovation. Perspectives on future opportunities for ion-track science and technology will also be presented.

Ion-track etched membranes provide a versatile platform for the fabrication of highly ordered one- and three-dimensional (3D) nanostructures with precisely controlled architectures. Such control over nanoscale geometry, connectivity, and interfaces is essential for understanding how structure governs material properties and for developing functional nanostructured materials. At GSI, polymer foils are irradiated with swift heavy ions at the X0 beamline and subsequently chemically etched to form nanochannels with tunable diameter, density, alignment, and geometry. Sequential irradiation from different directions enables complex 3D channel networks, which can be used as templates for the fabrication of free-standing nanowire and nanotube assemblies.

At the Materials Research Department, these tailored templates are combined with complementary deposition techniques, in particular electrochemical deposition and atomic layer deposition (ALD), to realize nanostructures with controlled composition, dimensions, and architecture. Electrochemical deposition enables the fabrication of metallic and semiconductor nanowires, while ALD provides conformal coatings of the channel walls and thus access to hollow nanotubes and nanoscale core-shell structures. These combinations offer independent control over both the geometry and materials composition of the resulting nanostructures.

Beyond the fabrication of well-defined nanostructures, we investigate and exploit nanoscale materials properties. Current activities include 3D nanowire architectures for thermoelectric applications, nanostructured materials for heterogeneous catalysis, and functional surfaces with tailored wetting properties. The controlled dimensions, interfaces, and architectures further enable systematic studies of structure-properties relationships, including size- and interface-dependent properties and their response to high pressure and ion irradiation. In this contribution, selected examples will be presented, highlighting how tailored nanochannel templates and complementary deposition strategies provide a versatile platform for developing functional materials for energy conversion, catalysis, and surface engineering, as well as well-defined model systems for materials research under extreme conditions.

The presentation will cover ESA’s needs for radiation testing of electronics,
materials, and other technologies for space applications, in support of
qualification, technology development, radiation hardness assurance and
failure investigations.
It will explain how the GSI UNILAC facility, and in particular the X0 heavy-
ion microprobe, can complement conventional radiation testing by enabling
localized investigations of radiation effects in electronic devices. The focus
will be on the use of these techniques to understand failure mechanisms, and
identify sensitive areas within circuits, rather than for qualification testing.
Examples from previous ESA-related studies on power MOS devices, Si and SiC
technologies, MIM/MIS capacitors and Flash memories will be presented to
illustrate the capabilities of broad-beam and microprobe irradiation.
The presentation will also discuss future applications of these techniques for
emerging technologies (FPGAs, microprocessors, AI accelerators, solid-state
memories, RF components, GaN and SiC devices, and image sensors). Their
complementarity with other radiation-effects investigation methods, such as
pulsed laser and pulsed X-ray techniques, will be highlighted in the context
of mechanism identification, pre-screening activities and technology development.
Optional:
Finally, an overview of the Materials & Electrical Components Laboratory, part
of the ESA/ESTEC TEC Laboratories, will be given, including its activities in
the areas of Materials, Environments and Contamination Control, Materials and
Processes, and Radiation and Component Reliability. The presentation will show
how ESA combines irradiation facilities and analytical techniques to evaluate
the effects of radiation on electronics and materials for space applications,
similarities, and possible synergies with the capabilities available at UNILAC.

The use of fast-timing radiation-resistant materials, e.g. diamond [1-3] or silicon [4], which will survive to the FAIR beam rates longer than plastics (typically lifetime of 1 week) has being investigated in the last decade using SIS18 ion beams produced at GSI. Despite the excellent results obtained, none of these options was suitable to cover an active area of 400x100 mm^2 for detecting radioactive ion beams to be produced at at FAIR.
On one side, high-quality radiation-hard sensors with an active area larger than 40x40 mm^2 are still not easily produced. In addition, a system with few ps timing resolutions would require a highly electrode segmentation of the sensors and then thousands of electronics channels.
New detector technology based on SiC material has been recently investigated for future GSI/FAIR applications. Two small thin SiC samples [5] were tested for the first time with 238U beams at different energies ranging from 300 up to 900 MeV/u. Successively, a thicker detector (100um) made of the same material (H4-SiC) was irradiated with 12C and 16O beams at 200-300 MeV/u at HIT in comparison to a single-crystal diamond detector.
The performed measurements and the achieved results will be discussed.

[1] F. Schirru et al., J. Phys. D: Appl. Phys. 49 (2016) 215105
[2] S. Schlemme et al., Diam. Relat. Mater. 99 (2019) 107536
[3] M. Alfonsi et al., JINST 19 (2024) C05009
[4] V. Eremin et al., JINST 12 (2017) C03001
[5] S. Tudisco et al., Sensors 2018, 18, 2289

Silicon carbide (SiC) power devices are promising for space applications but suffer from single event leakage current (SELC), single event burnout (SEB) and single event gate rupture (SEGR) under heavy ion irradiation. Our recent experimental and simulation studies have systematically investigated the mechanisms including heavy ion induced degradation in SiC junction barrier Schottky (JBS) diodes and power MOSFETs. In SiC JBS diodes, a graded buffer layer between epitaxy and substrate suppresses the electric field peak at the interface, raising the SEB threshold. Substrate thinning from 350 μm to 150 μm similarly reduces damage by lowering impact ionization and charge deposition. In SiC MOSFETs, increasing ion incidence angle mitigates both oxide and body damage. With varying gate oxide thicknesses, i.e. 48 nm and 56 nm, the experiments reveal that thicker oxide reduces gate to drain leakage but promotes drain to source leakage, indicating radiation damage redistribution rather than simple suppression. High resolution TEM directly observes nanoscale amorphous damage and atomic mixing at the Schottky interface, confirming localized melting as the reason cause of SELC. The combination of experimental characterization, TCAD simulations, and nanoscale material analysis provides a way for understanding heavy ion induced degradation and guiding radiation hardened design for power electronics devices.

The control interface to the microprobe has evolved pragmatically in step with user's needs over the past 40 years. In this process, utmost care was taken to create as little latency reacting to beam events as possible in order to accept the maximum amount of beam from the accelerator into the experiment. In the pre-FPGA or very early microcontroller era that meant implementing custom, hardwired dicrete electronic circuits. While the timing needs can be easily met that way, both experiment preparation and beam control rely on phyical interaction with circuitry and a plethora of knobs, DIP switches, and such to input irradiation parameters.
To allow for modern software interaction, scriptability, and remote operation, key control devices are now being retrofit with network interfaces and a soft real-time operating firmware. As an example, I will walk you through the upgrade of the beam scanning system.

We present a compact laser setup for investigating single-event-effects in semiconductors. In the presentation, we give an overview, how we used the setup for beamtime-preparation at GSI-microprobe with SuperJunction MOSFETs and microcontrollers as well as an overview of further use-cases.
The developed pulse-laser-setup uses an optical pick-up-unit of a DVD-writer including laserdiodes with 650 nm and 780 nm. A laser pulse-width in the range of 1-20 ns with an positioning accuracy below 250 nm is used for the investigations. For testing the test-setup of MOSFETs, the setup has been used to penetrate non-metalized border-areas of these devices to inject charges. So, the signal-chain could be optimized. Besides that, we developed a method to access the active structures of these fully top-side-metallized devices to investigate charge-injectin by laser-pulses. With microcontrollers, we use the setup for analyzing the parts-behaviour in case of single-event-latchups (SEL) and single-event-upsets (SEU). During our scans with the GSI-microprobe, we confirmed a similar behaviour of the previously laser-scanned parts. So, we found a spot with the laser in an ATtiny20, where it can be destroyed quickly by SEL and the timings are similar with ions. Another spot in this device is a location, where the Flash-memory can be erased with a single laser-pulse. This feature could also be confirmed with ions. SEL-mappings show many similar susceptible regions, with differences due to metallization and penetration-depth-dependencies.

The development of radiation-hard particle detectors is essential for next-generation nuclear physics experiments within the Facility for Antiproton and Ion Research (FAIR) framework. Among candidate materials, Chemical Vapor Deposition (CVD) diamond stands out due to its wide bandgap, high carrier mobility, and excellent radiation hardness, enabling operation in extreme environments [T. Shimaoka et al.,Functional Diamond, 2021, DOI: 10.1080/26941112.2021.2017758]. In this work, we present a complementary study to the development of CVD diamond detectors carried out by the CRYRING (GSI) group, with a focus on their application in beam diagnostics [R. Wallny et al., Pixel2022.].

CVD diamond samples were irradiated with 1.2 MeV Au ions, reaching fluences up to 1e14 ions/cm² at the 3 MV TandetronTM accelerator, from IFIN-HH, Romania. Between irradiation steps, defect density profiles were obtained using Rutherford Backscattering Spectrometry in channeling mode (RBS-C), allowing identification of threshold fluences where detector performance degrades. Positron Annihilation Spectroscopy (PAS) analyses were also applied to probe the level of vacancies and lattice damage. Electrical characterization was carried out using interdigitated electrodes (IDE) fabricated on the CVD diamond surface. The charge collection efficiency (CCE) was evaluated for the pristine material, after heavy-ion irradiation, and following ion-beam-induced defect recovery By correlating PAS and RBS-C, while assessing the electrical response enabled us to find a direct link between defect evolution and detector performance.

Post-irradiation with 12 MeV oxygen ions, at fluences up to 1e16 ions/cm², revealed partial recovery of defects and an improved electrical response, confirming the presence of electronic‑excitation‑assisted defect recombination processes. These results support the in-situ optimization of CVD diamond detectors for high-radiation environments relevant to future FAIR experiments.

The radiation-induced monoclinic-to-tetragonal phase transition in ZrO2 and HfO2 has been the subject of many investigations, but the transformation pathways and underlying structural mechanisms are still not well understood. In this study, microcrystalline powder samples of ZrO2 and HfO2 were irradiated with 946 MeV and 1470 MeV Au ions to a wide fluence range up to 3 × 1013 ions/cm2. To characterize beam-induced structural modifications across all spatial length scales, complementary experimental techniques such as synchrotron X-ray diffraction and spallation neutron total scattering were used. The phase evolution of the tetragonal polymorph with increasing ion fluence is accurately described by a heterogeneous track-overlap model that incorporates both direct- and double-impact processes [1]. These damage accumulation processes are an expression of a core-shell ion track morphology that depends on irradiation conditions and target material. Neutron pair distribution function analysis revealed that ion-beam-induced tetragonal ZrO2 is merely a configurational average of short-range orthorhombic (Pbcn) domains stabilized by a dense network of domain walls [2]. This knowledge is critical for a better understanding of how crystalline-to-crystalline phase transformations proceed at the atomic scale under extreme conditions.

[1] A.P. Solomon, E.C. O’Quinn, C.C. Overstreet, P. Simon, C. Trautmann, C.Y. Park, D. Sprouster, G. Baldinozzi, and M. Lang, Multi-Scale Structural Analysis of Swift Ion-Irradiated ZrO2 and HfO2, Acta Materialia A 306, 121926 (2026)

[2] A.P. Solomon, E.C. O’Quinn, J. Liu, I.M. Gussev, X. Guo, J. Neuefeind, C. Trautmann, R.C. Ewing, G. Baldinozzi, and M. Lang, Atomic-scale structure of ZrO2: Formation of metastable polymorphs, Science Advances 11, eadq5943 (2025)

The recent discovery of irradiation-induced self-organized formation of the β/γ-Ga₂O₃ double-polymorph structure has revealed new opportunities to study ion-beam-driven phase transformations in radiation-tolerant semiconductors. While most previous studies considered nuclear (Sₙ) and electronic (Sₑ) energy deposition as largely independent, their coupled effects and the resulting nonequilibrium structural evolution remain poorly understood.
To address these questions, IFIN-HH and the GSI MAT Group have initiated the FAIR-RO ATOM collaboration, combining intermediate-energy ion irradiations and ex situ ion-channeling measurements at IFIN-HH with swift heavy ion irradiations and in situ structural characterization at GSI. This complementary approach aims to clarify the role of coupled energy deposition in the evolution of the β/γ-Ga₂O₃ polymorph structure.
This contribution introduces the collaboration, outlines the experimental strategy, and presents the first irradiation campaigns designed to investigate phase transformations in Ga₂O₃ under extreme electronic excitation. These first steps lay the foundation for a broader research program aimed at understanding nonequilibrium processes in ion-irradiated materials and advancing the development of radiation-tolerant oxide semiconductors for operation in extreme environments.

To induce material modification, including ion track formation, under high-energy ion irradiation in the electronic stopping regime, the electronic stopping power (S_e) is one of the important parameters. Since Se increases with ion energy at low energies and then decreases at high energies, it exhibits a maximum whose value becomes larger for heavier ions. Therefore, among monatomic ions, the highest S_e is attainable with uranium ions. However, this maximum can be exceeded by cluster ions such as C60.
For example, the maximum S_e attainable with uranium ions in diamond is approximately 50 keV/nm, which was insufficient to form ion tracks. In contrast, 9 MeV C60 ions exceed this limit and successfully form ion tracks in diamond [1]. Furthermore, the exceptionally high S_e of C60 ions enables a regime in which both the electronic and nuclear stopping powers (S_e and S_n) are simultaneously high, resulting in ion track formation in crystalline Si under low energy 60 keV C60 ion irradiation [2,3].

References
[1] H. Amekura et al., Nat. Commun. 15, 1786 (2024).
[2] H. Amekura et al., Materialia 39, 102317 (2025).
[3] H. Amekura et al., NIMB 579, 166225 (2026).

Ultrathin and thin graphene oxide (GO) membranes with well-defined in-plane nanopores are promising for separation, sensing, molecular transport, and nanofluidic applications. A versatile route to fabricate such porous GO architectures is heavy-ion irradiation in the high electronic energy loss ($S_e$) regime or with intermediate-$S_e$ ions at grazing incidence ($1-10^\circ$). The resulting nanopores are well-defined and uniformly distributed, with partially restored sp$^2$-hybridized carbon around the pore periphery and oxygen-containing functional groups at the pore edges. This unique pore structure is expected to enhance mass transport through laminar membranes. However, controlled nanopore formation using intermediate-$S_e$ ions at normal incidence remains poorly understood, with previous studies reporting somehow contradictory results.
In view of the planned restart of the UNILAC accelerator with medium-intensity ion beams up to Xe, we will present a critical review of GO nanoperforation in this regime together with results from our recent pilot experiments at GANIL.
High-resolution TEM combined with EELS mapping of suspended single- and few-layer GO revealed that, compared with the high-$S_e$ regime, the resulting nanopores were generally smaller, less uniform in size, and created with lower efficiency. A similar trend was observed for supported GO membranes (100$-$500 nm thick), as evidenced by SAXS measurements and SEM imaging of the surface. The ion track halo extended to a radius of $\sim$10 nm and, with increasing distance from the track center, exhibited a gradual decrease in functionalization density and progressive restoration of the sp$^2$-hybridized carbon lattice.
Finally, we stress the role of GO chemical composition (functional group density, group types, and defect density) in governing the threshold conditions for nanopore formation.

This research was funded by the National Science Centre, Poland grant No. 2025/09/X/ST11/00589.

Radiation effects in polymers span a wide range of chemical and structural modifications, depending on the energy deposited by the ion and on the dimensions of the material. Our research has focused on polymer thin films as model systems for investigating these effects under controlled conditions of film thickness and ion irradiation. Over the past years, we have explored a broad range of electronic stopping powers, from low-dE/dx ions to swift heavy ions, together with different polymer systems and film thicknesses down to the nanometer scale. This approach has enabled the investigation of ion-track formation, bond breaking, substrate effects, and irradiation-induced thinning within a common framework. Different aspects of the radiation response emerge depending on the irradiation regime and film dimensions. In particular, chemical damage and material loss do not necessarily follow the same thickness dependence. XPS, FTIR, AFM, and AFM-IR have therefore been used as complementary probes of chemical composition, molecular modification, film-thickness evolution, and spatially resolved damage. Recent results further show that damage cross sections derived from these techniques can exhibit different thickness dependences, raising questions about the relationship between the measured response and the underlying microscopic processes. These observations motivate broader studies of radiation effects in confined materials, where the interplay between energy deposition, material dimensions, interfaces, and chemical response remains to be fully understood. Addressing these questions through complementary experimental approaches and expanded ranges of materials, geometries, and irradiation conditions may provide new insight into radiation-induced processes at reduced dimensions.

Over the past decades, the effects of swift heavy ion (SHI) irradiation have been extensively studied across a wide range of materials. Most of these investigations have focused on bulk materials, providing fundamental insights into irradiation-induced processes and supporting the development of materials for high-radiation environments such as nuclear facilities, particle accelerators, and satellite components. However, when materials dimensions are reduced to the nanoscale, the irradiation response can differ substantially from that of bulk materials. Despite the growing use of nanostructured materials in radiation-relevant applications, the influence of size and geometry on SHI-induced modifications is not yet fully understood.
In this work, we investigate swift heavy ion–induced effects in nanostructures and thin films, with a focus on systematically studying size-dependent morphological and structural changes. Various nanomaterials are exposed to 1–2 GeV heavy ions at the GSI UNILAC accelerator under controlled irradiation conditions. High-resolution electron microscopy is used to characterize the resulting modifications and to identify size-dependent irradiation effects and their relation to the nanostructure geometry. Complementary molecular dynamics simulations provide further insight into the underlying mechanisms of energy deposition and material transformation connecting the observed structural changes with their atomistic origin.

In cold space environments, the synthesis of organic molecules can occur following radiolysis of small molecules (H2O, CO, CH4, NH3 etc.) on cold surfaces like dust grains (molecular clouds) and icy bodies of the solar system [1].
We performed swift ion irradiation experiments related to formation and destruction of organic molecules at different accelerator facilities (GANIL, Caen/France, GSI, Darmstadt/Germany and ATOMKI, Debrecen/Hungary) in a wide temperature range (10-300K). Within the PEPR Origins [pepr-origins.fr], a unique multi-beam irradiation device (UV photons, keV electrons and keV-GeV ions delivered by GANIL/Caen), the MIRRPLA platform, open to the various scientific communities (astrophysics, radiobiology, environmental and materials sciences) is currently being built [2].
Infrared absorption spectroscopy FTIR and mass spectrometry QMS allow in situ observation of processing of the icy layers. Ex-situ analysis of residues is performed by e.g. high-resolution mass spectrometric methods. We present results obtained in the past and future projects, with special emphasis on our studies at the M3 beamline at UNILAC (see [3] and references therein).

[1] H. Rothard, A. Domaracka, P. Boduch, M. E. Palumbo, G. Strazzulla, E. F. da Silveira and
E. Dartois, Modification of ices by cosmic rays and solar wind, J. Phys. B : At. Mol. Opt. Phys. 50, 062001 (2017), doi: 10.1088/1361-6455/50/6/062001
[2] Alicja Domaracka and Grégoire Danger, Multiple Beam Irradiation Platform MIRRPLA: Origin and Evolution of Organic Matter in the Solar System, Nuclear Physics News 33(4), 36–37 (2023), doi: 10.1080/10619127.2023.2265772
[3] C. Mejía, G. S. V. Muniz, M. Bender, D. Severin, C. Trautmann, A. N. Agnihotri, B. Augé, A. Domaracka, P. Boduch, H. Rothard, Swift heavy ion irradiation of Thymine at cryogenic temperature, Nucl. Instum. Meth. B534 (2023) 11-15, doi: 10.1016/j.nimb.2022.10.024

In this talk, we will provide an overview of the irradiation and in situ analysis facilities present at the beamline M3 at UNILAC. A focus will be on recent projects and developments related to questions in astrochemistry - from a detailed view on the radiolysis of complex organix molecules to effects of space weathering on cosmic dust analogues [1,2].

Moreover, we will provide a short outlook on plans for future developments of the instrumentation at the beamline, with added capabilities for in situ cryogenic sample preparation.

[1] Schneider, P., Keller, P., Schubert, I. et al. Bond-specific fragmentation of oligopeptides via electronic stopping of swift heavy ions in molecular films. Sci Rep 12, 17975 (2022). https://doi.org/10.1038/s41598-022-21744-w
[2] Abdo, E., Dartois, E., Chabot, M. et al. Heavy-ion irradiation of interstellar carbonaceous and siliceous composite dust analogs. Cosmic ray-grain interactions at the nanometer scale
A&A, Forthcoming article, https://doi.org/10.1051/0004-6361/202659972

β-Ga2O3 has attracted growing attention as a new wide-bandgap semiconductor material, because it has an extremely high bandgap energy of 4.8–4.9 eV and an expected high breakdown field of 8 MV/cm. Understanding irradiation effects on β-Ga2O3 materials is essential to evaluate the electrical performance and reliability of devices in harsh radiation environments. The ion tracks and the thermal stability (473-773 K) in β-Ga2O3 single crystal irradiated with ∼5–19 MeV/u swift heavy ions (SHI) were investigated by transmission electron microscopy and atomic force microscopy (AFM). It indicates that the threshold of ion track formation is ~17 keV/nm, which is much lower than that of other wideband semiconductors, such as GaN, SiC, AlN and diamond. The average diameter and morphology of tracks annealed at 673 K or above undergo a significant change due to recrystallization. Annealing at 773 K reduces the areal track density to approximately 50%. The activation energy for thermal recovery was determined to be 0.27±0.03 eV. These findings provide valuable information for assessing the reliability of β-Ga2O3-based devices intended for operation in harsh environments.

Gallium oxide (Ga₂O₃) is a compelling member of the polymorphic oxide family, where ion beam modification offers a powerful route to tailor material structure and functionality. While the creation of defects in this crystal through elastic energy transfer (Sₙ) is well established and drives, for example, monoclinic‑to‑orthorhombic transformations, the role of inelastic energy loss (Sₑ) remains more complex, particularly when the material already contains disorder. In this context, it is important that the fundamental understanding of how Ga₂O₃ responds to highly-ionizing swift heavy ion (SHI) irradiation does not lag behind insights gained for other semiconductors and complex oxides [KTaO₃ - G. Velișa et al., J. Phys. D: Appl. Phys. 2021].

To address this gap, we designed an experiment to test whether damage‑reducing and damage‑enhancing mechanisms can coexist under identical SHI irradiation conditions. β‑Ga₂O₃ samples were first pre‑damaged using 1.2 MeV Au ions from the 3MV Tandetron™ from IFIN-HH at fluences of 0.3, 1.0 and 10.0 nm⁻², generating controlled initial disorder states, and then irradiated at room temperature with 8.6 MeV/u Au ions (Sₑ ≈ 43 keV/nm) at GSI. Ex-situ RBS/C measurements, performed at IFIN-HH, quantified damage evolution before and after irradiation in both undamaged and pre-damaged samples.

The SHI response was found to depend strongly on the initial defect state. The least‑damaged sample exhibited partial recovery of pre‑existing defects, consistent with electronic‑excitation‑induced annealing [Iancu et al., Scripta Mater. 2025], while the most heavily pre‑damaged sample showed clear signatures of ion‑track formation, with data also hinting at localized phase transformation around the track core, in agreement with recent computer simulations [Han et al., Adv. Sci. 2025]. These results demonstrate that the initial disorder state acts as a tunable variable for selectively activating ionization‑driven processes in Ga₂O₃.

Swift-heavy-ion irradiation experiments under high static pressures in diamond anvil cells (DACs) have shown that ion-induced processes can drastically influence the pressure-dependent phase behavior of materials. For example, irradiation can transform zirconia (ZrO$_2$) into the orthorhombic-II phase or induce the formation of the high-pressure zircon (ZrSiO$_4$) polymorph reidite at pressures far below its equilibrium transition pressures. [1-3] These findings demonstrate that irradiation under pressure enables access to otherwise inaccessible phases. Ion irradiation can also help stabilize high-pressure phases upon decompression. To improve spectroscopic access to experiments involving ion irradiation in DACs, a dedicated setup was developed in which irradiation occurs through the gasket rather than through the diamonds. [4] Building on this, a new project aims to extend the approach by enabling temperature control between 10 K and 1000 K during irradiation at pressures up to 80 GPa. This will allow systematic studies of beam-heating effects and phase stabilities. Furthermore, the deployment of diamonds with embedded electrodes will allow for in situ electrical conductivity measurements, providing real-time insights into irradiation-induced melting and defect-related electronic changes. Together, these developments will create a unique platform for investigating the coupled effects of pressure, temperature, and ion irradiation on condensed matter.
We acknowledge funding from the BMBF (05K25RF3) and the DFG (BA4020, WI1232).

[1] B. Schuster et al., Nucl. Instrum. Methods Phys. Res. B 2009, 6, 964-968, DOI: 10.1016/j.nimb.2009.02.046
[2] M. Lang et al., Earth Planet. Sci. Lett. 2008, 269, 291-295, DOI: 10.1016/j.epsl.2008.02.027
[3] J. Liang et al., Phys. Chem. Chem. Phys. 2026, 28(13), 7835-7839, DOI: 10.1039/d6cp00307a
[4] I. Tzifas et al., Phys. Rev. Res. 2026, 8, 023054, DOI: 10.1103/q8w6-wttf

Beam nanolattice is a new class of mechanical metamaterials with characteristic sizes on the order of hundreds of nanometers. Due to extremely special size effects, structural characteristics and material selection, the mechanical properties of this type of porous materials can simultaneously achieve high strength and high strain with lighter weight, which is expected to bring revolutionary applications in the field of high-performance functional materials in the future. However, the traditional photochemical preparation technology is limited by the optical diffraction limit, it is challenging to make breakthrough in the precise fabrication of metallic beam nanolattice with beam diameter of less than 100 nm, and thus their mechanical properties remain ambiguous.
In this work, a new type of quasi-body centered cubic (quasi-BCC/BCCZ) beam nanolattice mechanical metamaterial is proposed, which is experimentally implemented with ion track technology based on the Heavy Ion Research Facility in Lanzhou (HIRFL). The beam diameter can be as small as 34 nm, breaking through the size limit of the beam nanolattices mechanical metamaterials. In situ compression experiment results show that the energy absorption capacity of the quasi-BCC/BCCZ beam nanolattice exceeds that of the previously reported beam nanolattices. This work deepens the understanding of the mechanical properties of beam nanolattices. At the same time, the application of ion track technology in the study of nanostructured materials is realized, which provides a new idea for the exploration of beam nanolattice with ultra-high energy absorption capacity.

The rainbow effect is a fundamental phenomenon in any scattering theory of waves and particles, describing the accumulation of trajectories at characteristic angles due to extrema of the deflection function. In particular, the atomic rainbow effect – arising in semiclassical particle scattering due to singularities in the classical differential cross section – provides valuable information about the interaction potential between a projectile and target atoms, which is of particular interest for two-dimensional systems. However, experimental observation of the atomic rainbow effect in two-dimensional materials is highly challenging, as both an atomically clean target and a high-resolution detector are required.

Here, we present the experimental observation of rainbow scattering in ion transmission through single-layer graphene using time-of-flight medium energy ion scattering [1]. For 40 keV Xe$^{+}$ ions, the observed scattering pattern exhibits two distinct components: a circular outer rainbow at 5.28°, associated with maximum binary collision deflection from individual carbon atoms, and a hexagonal inner rainbow at 0.43°, originating from projectiles with characteristic trajectories interacting with multiple carbon atoms. Molecular dynamics and binary collision simulations reproduce these regimes and clarify their physical origins, but fail to capture the measured intensity distribution at the smallest deflection angles when using averaged radially symmetric interaction potentials. These results establish graphene rainbow scattering as an experimental benchmark for ion-solid interaction potentials and reveal limitations of commonly used approximations in describing many-body scattering dynamics. The cleanliness of the graphene sample is quantified using a recently developed method based on recoil-projectile coincidence in ion scattering experiments.

References
[1] C. Frank et al., Carbon 257 (2026)

The simultaneous exposure of materials to high pressure and swift heavy-ion irradiation represents a unique experimental approach, pioneered at the GSI Helmholtz Center Darmstadt [1-3]. Ion-irradiation induced structural transformations have been observed in compressed samples, including non-equilibrium phase transitions [1], the formation of novel phases and their stabilization [2].

Here we present the recently commissioned experimental platform for the investigation of coupled extreme conditions [3]. It enables the exposure of micrometer-sized samples compressed to high static pressures in diamond anvil cells (DACs) to swift heavy ions with energies between 200 and 480 MeV/u, providing in-situ Raman spectroscopy and optical microscopy while minimizing ion irradiation induced effects in the DAC [3]. Technical developments and capabilities of the setup are presented along with selected results on coupled ion-irradiation-pressure-induced modifications in various materials.

The authors gratefully acknowledge funding and beamtime provided by the GSI Helmholtz Center, as well as synchrotron beamtime at PETRA-III, DESY (Hamburg, Germany) and funding from the BMFTR (05K25RF3 and 05K22RF3).

[1] Glasmacher, U.A. et al., Phys. Rev. Lett., 96(19), 2006, p. 195701
[2] Lang, M. et al., Nat. Mat., 8(10), 2009, p. 793
[3] Tzifas, I. et al. Phys. Rev. Res., 8(2), 2026, p. 023054
[4] Schröck, C. et al., Phys. Rev. B, 112(1), 2025, p. 014111
[5] Liang, J. et al., Phys. Chem. Chem. Phys., 28(13), 2026, 7835-7839.

Swift heavy ion (SHI) irradiation creates unique extreme conditions because each ion deposits a large amount of energy within a localized region [1,2]. Such intense excitation can induce local melting, amorphization, defect formation, phase transformations, and rapid recrystallization [1]. An important consequence is the modification of interatomic bonding and the local chemical environment, particularly in molecular crystals held together by weak intermolecular interactions. We have demonstrated that the combination of high pressure and SHI irradiation can strongly modify the bonding and structural configurations of molecular solids, such as carbon monoxide (CO), urea, and sulfur (S) [3]. Where SHI irradiation induced polymerization of CO, decomposition and disordering of urea, and ring-opening polymerization of S₈.

We have also investigated the effects of SHI irradiation on sp²-bonded conjugated systems, including benzene and graphite, under high pressure [4]. In benzene, we observed irradiation-induced amorphization of the molecular crystal at pressures substantially below those required for the corresponding phase transition without irradiation. In graphite, SHI irradiation resulted in the formation of amorphous carbon with grain sizes of only a few nanometers, accompanied by partial conversion of the carbon atoms from sp² to sp³ hybridization.
Overall, our results demonstrate that SHI irradiation provides a kinetically controlled pathway for driving molecular and carbon-based solids toward structural and chemical states that may not be accessible through pressure alone.

We acknowledge funding from the BMBF (05K22RF3, 05K25RF3) and the DFG (BA4020, WI1232).

[1] M. Lang et al., Comprehensive Nuclear Materials, 2020, 485-516
[2] I. Tzifas et al., Physical Review Research 8, 2026, 023054
[3] L. Jiaxu, et al., Phys. Chem. Chem. Phys., 2026, 28, 7835
[4] L. Jiaxu, et al., in preparation, 2026

The energy deposition of ions in water generates pressure waves, known as ionoacoustic signals. These are commonly described within the thermoacoustic approximation, where localised heating and subsequent volume expansion are considered the primary sources of wave generation. According to this model, no pressure wave should be observed at 4 °C, a prediction confirmed in laser absorption experiments. However, when initiated by protons, the minimum of the acoustic signal shifts to significantly higher temperatures, suggesting the presence of an additional, non-thermal excitation mechanism.
We present the first experimental investigation of this effect using heavy ions (²³⁸U and ¹⁰⁰Mo), conducted at the SIS-18 accelerator at GSI Darmstadt. By analysing the polarity change of the pressure wave near the water anomaly at 4 °C, we observed distinct directional dependencies in the lateral and axial components of the acoustic signal, indicating a pronounced and unexpected directionality in the excitation process.
These findings may enable novel diagnostic techniques and contribute to a broader understanding of mechanically induced radiation damage.

The two experimental target stations operated by the University of Duisburg-Essen (UDE) for ion–matter interaction studies at GSI will be presented, with a focus on the ToF-SIMS/SNMS setup at the M1 beamline of the M-branch. The setup enables direct in-situ comparison of ion-induced particle emission under both swift-heavy-ion and keV ion bombardment using mass-spectrometric detection. Examples obtained with swift heavy ions, 5 keV Ar⁺, and 20 keV C₆₀⁺ projectiles will illustrate the accessible range of experiments, including identification of sputtered species, ion-induced molecular fragmentation, ionization probabilities, and velocity distributions of sputtered particles. These capabilities are relevant to a broad range of applications, ranging from astrochemistry and organic materials to prospective studies of fusion-relevant materials.

In addition, the extraction beamline and target station at CRYRING will be introduced. Transmission measurements for characterization of the experimental setup, as well as first in-situ Raman studies of ion-induced defect formation in graphene, will be presented.