The article introduces a new approach for systemlevel observation during radiation testing which is based on the in-system monitoring of analog signals. The verification of the test method is performed using an example mixed-signal system, in which the sampled signals are the outputs of the Point-of-Load (PoL) power regulators. The collected data is then used to analyze the in-system performance of electronic components and establish the connection between system-level failures and device-level radiation-induced effects. Moreover, the contribution of SingleEvent Effects (SEEs) taking place in specific power converters to the overall system-level failure rate was determined. The presented analysis concerns the results of three test campaigns, where the designed observation approach was verified within different radiation environments.

The qualification of space electronics increasingly relies on very-high-energy heavy ion (VHEHI) beams, which provide deep penetration and high linear energy transfer (LET), enabling realistic testing of complex, packaged commercial-off-the-shelf (COTS) components or full boards. However, dosimetry at these energies remains challenging, and harmonized approaches across facilities are lacking. A dosimetry method combining energy deposition spectra measured by a commercial silicon detector with FLUKA Monte Carlo simulations was previously developed and benchmarked at CERN within the EU-funded HEARTS project. In this work, the method was validated through a systematic intercomparison of four leading VHEHI facilities: GSI, HIMAC, NSRL, and CERN. Across all facilities, a strong linear correlation between measured and simulated peak energy deposition values was consistently observed, demonstrating the robustness of the approach for reliable LET extraction. Facility-specific insights were obtained: accelerator energy variation is preferable to heavy degradation to minimize LET spread, heavier ions outperform degraded lighter ions, and CERN’s tailored lead-ion beams now provide LET coverage comparable to reference facilities. Complementary pulse-shape analysis further identified detector-related artifacts and allowed to refine the measured energy deposition spectra. This work establishes a validated framework for unified VHEHI dosimetry, supporting harmonization of test protocols and enabling reliable radiation effects qualification of next-generation space electronics with VHEHI beams in Europe and worldwide.

The present study investigates the effects of neutron shielding by concrete slabs in the context of nuclear fusion (14 MeV neutrons). MCNP and Geant4 numerical simulations have been performed to characterize neutron transport through concrete slabs with thicknesses ranging from 1 to 160 cm. Using a monoenergetic, normally incident 14 MeV neutron source, we examine neutron-flux attenuation and spectral evolution after propagation through concrete. The results show that multiple elastic and inelastic scattering processes dominate the transport, leading to a strong spectral redistribution and a significant build-up of scattered neutrons. For intermediate thicknesses (50–100 cm), the transmitted flux is largely composed of scattered and secondary neutrons, with a pronounced epithermal slowing-down component approximately following a 1/E behavior, a thermal peak resulting from hydrogen moderation, and a residual high-energy tail corresponding to partially degraded primary neutrons. At larger thicknesses (≥100 cm), absorption and capture of thermalized neutrons become dominant, resulting in a sharp decrease in the transmitted flux. The impact of these spectral modifications on the soft-error rate (SER) of microelectronic devices is evaluated by folding the transmitted neutron spectra with energy-dependent single-event upset (SEU) cross-sections representative of advanced semiconductor technologies. The results indicate that, although total neutron flux decreases significantly with increasing concrete thickness, the spectral redistribution and the persistence of intermediate-energy neutrons can maintain a non-negligible contribution to SER in certain configurations. These findings highlight the importance of using full transport simulations, including spectral effects, when assessing radiation-induced reliability risks in fusion facilities.

Single-event latch-up (SEL) cross sections of static random access memory (SRAM) at high energy (100-200 MeV) are generally not reproducible with 14-MeV neutrons, differently to single-event upset (SEU) cross sections. We explain this phenomenon through Monte Carlo simulations, analyzing neutron-silicon interactions and the indirect energy deposition in sensitive volumes (SVs) resembling the two mechanisms, showing that the former approach is not sufficient to explain how the energy is deposited. The SRAMs were characterized in monoenergetic and spallation facilities and their Monte Carlo model was validated using various particle beams. Additionally, the contribution of individual ions to the SEU and SEL cross sections is quantified, demonstrating the distinct impact of these ions in the two mechanisms. For instance, alpha particles play a significant role in triggering SEUs, while they hardly induce SELs. This is related to the energy released by the ion in correlation with its range and the size of the SV. Finally, the models are validated against thermal neutrons, and the SEL sensitivity is also investigated, demonstrating the absence of SEL for devices with a linear energy transfer (LET) threshold above 2 MeV $\,\cdot \, \text {cm}<^>{2}/\text {mg}$ .

A new experimental area, the NEAR station, has recently been built at the CERN n TOF facility, at a short distance from the spallation target (1.5 m). The new area, characterized by a neutron beam of very high flux, has been designed with the purpose of performing activation measurements of interest for astrophysics and various applications. The beam is transported from the spallation target to the NEAR station through a hole in the shielding wall of the target, inside which a collimator is inserted. The new area is complemented with a γ-ray spectroscopy laboratory, the GEAR station, equipped with a high efficiency HPGe detector, for the measurement of the activity resulting from irradiation of a sample in the NEAR station. The use of a moderator/filter assembly is envisaged, in order to produce a neutron beam of Maxwellian shape at different thermal energies, necessary for the measurement of Maxwellian Averaged Cross Sections of astrophysical interest. A new fast-cycling activation technique is also being investigated, for measurements of reactions leading to isotopes of very short half life.

We performed soft error rate (SER) characterization of 40-and 65-nm bulk CMOS static random access memories (SRAMs) combined with neutron spectrometry in the deuterium-tritium (D-T)-fueled Joint European Torus (JET) tokamak during its final D-T plasma operation (September and October 2023) producing a series of several dozens of power pulses. Our experimental results demonstrate the impact of machine operation on the electronics' reliability, emulating realistic conditions for circuits exposed to the partially radiation-shielded environment of future fusion reactors. Typical bit-flip (BF) rates of 493 h(-1)Gbit(-1) for 65-nm SRAMs and 2342 h(-1)Gbit(-1) for 40-nm SRAMs were measured for a residual machine-induced neutron flux of similar to 3.15 x 10(5) cm(-2)s(-1) below the reinforced concrete slab (thickness of 1045 mm) supporting the tokamak chamber. To complete this characterization work, a general methodology for the SER prediction in such a mixed-field D-T neutron radiation environment composed of both thermal and fast neutrons (FN) (up to 14 MeV) is presented and validated from this ensemble of experimental data for the two SRAM technologies. Finally, the interest in this approach for future tokamaks and high-energy physics accelerators is discussed.

Single event effect cross sections and energy deposition events in silicon diodes were measured with high-energy heavy ions at HIMAC, in Japan, by varying LETs through PMMA degraders. Primary beam energies of 178 MeV/n 132Xe and 320 MeV/n 84Kr, measured at the device under test position, were employed. Results were compared to those from other heavy ion facilities, highlighting the importance of facility inter-comparisons. Considerations about single event upset cross sections, measured with and without the package and with fully fragmented beams, are outlined.

The HEARTS@CERN activity in the framework of the HEARTS (High-Energy Accelerators for Radiation Testing and Shielding) EU project is targeted at enhancing Europe’s high-energy (>100 MeV/n) heavy ion electronics irradiation capability through the development of an irradiation beam combining unique penetration and ionization characteristics. These types of tests are essential for exploiting commercial electronics in space. Throughout 2024, the HEARTS@CERN efforts have focused on achieving and demonstrating compliance with the space user radiation effects testing requirements. This includes being able to offer a wide range of energies (and Linear Energy Transfer values) and fluxes, with a high level of accuracy and a rapid change between parameters. Moreover, large homogeneous beams are necessary for enabling the test of multiple electronic components in parallel, and for performing board level testing. This work will present requirements for high-energy heavy ion testing along with the level of compliance achieved, as demonstrated during the November 2024 HEARTS@CERN user run, with a focus on the beam related parameters, but including also facility and procedural considerations.

The possibility of using calibrated static random-access memory (SRAM) memory for the quantification of neutron fluence in a radiotherapy facility for cancer treatment utilizing a high-energy 15-MV photon beam (Bremsstrahlung) from an electron linear accelerator has been exploited in this work. This has been performed by varying the field size of the photon beam and the positioning of the SRAM memory at three different positions in relation to the isocenter of the beam. The measurements demonstrated that neutrons originating from interactions between the high-energy photons and accelerator parts with high-Z materials are able to induce single-event upsets (SEUs) in the SRAM memory, where the measured SEUs depend on the measurement location. Monte Carlo (MC) simulations have been performed to retrieve the neutron fluence under each investigated measurement condition. Using the simulated neutron fluence differential in energy and the interactions cross sections determined previously, the expected SEUs were computed. The comparison between measured and simulated SEUs normalized to the linear accelerators (linac) output shows acceptable agreement within the experimental uncertainties. As exposure to secondary neutrons poses a risk to all patients, especially the ones with pacemakers or other electronical aids, the feasibility of establishing the neutron fluence through SEU quantification in an SRAM device provides new opportunities to estimate the associated risk in a clinical environment. Further work can be performed to investigate the correlation between the high-Z linac components and the neutron fluence during patient irradiation to better comprehend the variation between different linac types and manufacturers.

We present a calibration of a commercial silicon diode with proton and alpha beams and gamma rays. The diode together with a fast acquisition chain can be exploited for both direct and indirect (through the secondary radiation field) beam characterization. Within this work, we demonstrate the detector capabilities of resolving single-energy-deposition events and independently measuring dose rate and beam flux. Profiting from the mixed radiation field in CERN's high-energy accelerator mixed field facility (CHARM) we show how the silicon detector can be exploited to characterize the mixed radiation field present in it, which in turn is used for validating the radiation tolerance of components and systems to be installed in the European Organization for Nuclear Research (CERN) accelerator complex.

We present applications of a large commercial silicon diode (50 cm 2 x 500 um) for monitoring low-intensity radiation fields, together with benchmarks via Monte Carlo simulations. After the energy calibration with monoenergetic proton and alpha beams in the 2-8 MeV range, we show that the detector is capable of measuring atmospheric radiation at the ground level, not only in terms of a total number of events but also through their energy deposition distribution. Focusing on the atmospheric-like neutron spectrum, we prove that the diode detection cross-section is more than 5 orders of magnitude larger with respect to SRAM-based solutions, and highlight the potential use cases in the accelerator’s radiation environment.

We have performed real-time soft error rate (SER) measurements on bulk 65 nm static random-access memories (SRAMs) during deuterium–deuterium (D-D) plasma operation at W–tungsten– Environment in Steady-state Tokamak (WEST). The present measurement campaign was characterized by the production of several tens of long pulse discharges (~60 s) and by a total neutron fluence (at the level of the circuits under test) up to ~10 9 n.cm -2 , improving the error statistics by a factor of more than 6 with respect to the first measurements obtained in 2020. Experimental results demonstrate the occurrence of bursts of single-event upsets (SEUs) during the most efficient shots and 12% of multiple cell upset (MCU) events. Time-resolved data also show that MCUs are preferentially detected in the last part of these long pulses, providing further evidence that higher energy neutrons, initiated by deuterium–tritium (D-T) reactions due to triton burn-up in the D-D plasma, may play a role in the production of multiple cell upsets that cannot be attributed in such large proportions to “low energy” neutrons produced in D-D reactions.

ITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called 'Preparation of ITER Operation' (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16-21 October 2023) London, UK [www.iaea.org/events/fec2023]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium-tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc).

Ultra-high energy (> 5 GeV/n) heavy ion beams exhibit different properties when compared to standard and high energy ion beams. Most notably, fragmentation is a fundamental feature of the beam that may have important implications for electronics testing given the ultra-high energies, and hence ranges, preserved by the fragments. In this work, both the primary lead ion beam, available in the CERN North Area, and its fragments are characterized by means of solid-state detectors. This input is later used to improve the measurements of Single Event Effects in commercial components with this beam. Moreover, the energy deposition distribution in the solid-state detectors is compared to that obtained with Monte Carlo simulations.

The NEAR Station is a new experimental area developed at the n_TOF Facility at CERN. The activation station of NEAR underwent a characterization of the beam following the installation of the new n_TOF Spallation Target. The commissioning of the neutron beam comprises a set of simulations made with the FLUKA code and experimental verification. The experimental determination of the neutron spectrum was made using activation techniques with three separate set-ups. Two set-ups were based on the Multi-foil Activation technique (MAM-1 and MAM-2), and the third set-up relied on the process of neutron moderation and activation of a single material (ANTILoPE). The three set-ups are presented. Also the present plans and future perspectives of the activation station of NEAR are discussed.

The radiation showers generated by the interaction of high-energy electrons with matter include neutrons with an energy distribution peaked at the MeV scale, produced via photonuclear reactions, allowing measurements of neutron-induced single-event effects (SEEs) in electronic devices. In this work, we study a setup where the 200-MeV electron beam of the CLEAR accelerator at European Organization for Nuclear Research [Centre Européen pour la Recherche Nucléaire (CERN)] is directed on an aluminum target to produce a radiation field with a large neutron component. The resulting environment is analyzed by measuring the single-event upset (SEU) and latchup rates in well-characterized static random access memories (SRAMs), as well as the total ionizing dose (TID) in passive radio-photoluminescence (RPL) dosimeters, and by comparing the results with predictions from FLUKA simulations. We find that a lateral shielding made of lead protects the SRAMs from an excessive TID rate, yielding an optimal configuration for SEU measurements, particularly in SRAMs that are highly sensitive to MeV-scale neutrons. This setup provides an interesting complementary neutron source with respect to standard neutron facilities based on spallation targets or radioactive sources.

We study the neutron field at the NEAR station of the neutron time-of-flight (n_TOF) facility at CERN, through Monte Carlo simulations, well-characterized static random access memories (SRAMs), and radio-photoluminescence (RPL) dosimeters, with the aim of providing neutrons for electronics irradiation. Particle fluxes and typical quantities relevant for electronics testing were simulated for several test positions at NEAR and compared to those at the CERN high-energy accelerator mixed-field facility (CHARM), highlighting similitudes and differences. The SRAM detectors, based on single-event upset (SEU) and single-event latch-up (SEL) counts, each one with a different energy response, and RPL dosimeters were tested in a reference position, and the results were benchmarked to FLUKA simulations. Finally, the neutron spectra at NEAR are compared to those of the most well-known spallation sources and typical environments of interest, for accelerator and atmospheric applications, showing the potential of the facility for electronics irradiation.

RADNEXT is an EU-funded network of irradiation facilities and radiation effects’ experts aimed at increasing the quantity and quality of user access to accelerator infrastructure and improving the diversity and harmonization across facilities. Along with beam provision to worldwide radiation effects’ users, RADNEXT has an ambitious research program oriented at improving radiation effects’ testing, of which an example of a heavy ion facility intercomparison at very different energy regimes is included in this work. In particular, energy deposition distributions in a silicon solid-state detector and the single-event upset (SEU) and multiple-cell upset (MCU) behavior are compared among heavy ion beams of similar LET, but very different energies (i.e., from the more classical ~10 MeV/u regime up to several hundreds of MeV/u).

We study the radiation environment near the terahertz (THz) dump of the CERN Linear Electron Accelerator for Research (CLEAR) electron accelerator at CERN, using FLUktuierende KAskade in German (FLUKA) simulations and single-event upset (SEU) measurements taken with 32-Mbit Integrated Silicon Solution Inc. (ISSI) static random access memories (SRAMs). The main focus is on the characterization of the neutron field to evaluate its suitability for radiation tests of electronics in comparison with other irradiation facilities. Neutrons at CLEAR are produced via photonuclear reactions, mostly initiated by photons from the electromagnetic cascades that occur when the beam is absorbed by the dump structure. Good agreement is generally found between the measured single-event upset (SEU) rates and the expected values obtained from FLUKA simulations and the known SEU response of the ISSI SRAMs to neutrons, while one position is found to be potentially affected by photon-driven SEUs.

A single-event effect (SEE) simulation toolkit has been developed at CERN for the whole radiation effects community and released as an open-source code. It has been validated by comparing the simulated energy deposition of inelastic interactions, due to monoenergetic neutrons in the 1.2–17 MeV energy range, to the distribution measured experimentally by a silicon diode detector.