9th Annual RaDIATE Collaboration Meeting

16 sept 2024, 1:00 → 18 sept 2024, 19:30 Europe/Madrid

Granada

The 9^th Annual RaDIATE Collaboration Meeting, will be hosted by the Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) and the Consorcio IFMIF-DONES España. It will be held at the Palacio de Quinta Alegre, Granada, Spain on September 16-18, 2024. 

This collaboration meeting provides a forum for discussion between experts in this specialized domain. Collaboration members gather at a different host institution’s laboratory each year to address topical issues associated with radiation damage in the accelerator target’s environment.  

Topics discussed include but not limited to: 
       • Facilities design and operation
       • Applications with radiation damage concerns
       • Radiation damage studies and related simulations
       • Low-energy irradiation studies
       • High-energy proton irradiation studies
       • Thermal shock studies
       • Radiation-tolerant material development
       • Irradiation facilities 
       • Post-irradiation examination facilities and remote handling techniques.

Some Important News:

The deadline of On-Site Registration and Payment has been extended to August 28^th 2024.

The Abstract Submission deadline for Contributions has been extended to September 10th, 2024. We kindly encourage to the registered participants to submit their abstracts as soon as possible so we can prepare the Program. 

Remote participation and contributions are possible. Please, register through the corresponding Registration Form.

Regarding the night-visit to the Alhambra on September 17th evening at 21:30 (Costs of the visit are included in the Registration Fees). The registration deadline has been expired. Nevertheless, it may be still possible to try to book some tickets for registered people that has missed the deadline. If this is your case and you are still interested, please contact aida.padial@ifmif-dones.es as soon as possible indicating your full name and ID details (tickets are nominative).

The 300 € (VAT included) full-conference registration fees include:

       - Admission to meeting sessions on September 16-18 2024.

       - Coffee breaks.

       - On-site lunches on September 16-18.

       - Dinner on Monday 16th 20:00 at "Bheaven Restaurant Barceló Carmen Granada"

       - Night visit Tour Alhambra. 17th at 21:30

 

       - Visit of IFMIF-DONES Site and Labs on 18th afternoon, including transport

In case an Invitation Letter is required, please contact to aida.padial@ifmif-dones.es to request it. 

We are very excited to see you soon and looking forward to your contributions and participation!

The RaDIATE Collaboration

lunes, 16 de septiembre

8:30 → 9:00 Registration

Important_Welcome_Information.pptx

9:00 → 10:15 Welcome and introductory session

9:00 Welcome and RaDIATE Collaboration Update

In order to operate reliable beam-intercepting devices in the framework of energy and intensity increase projects of the future, it is essential to develop a strong R&D for robust target and beam window. The international RaDIATE collaboration, established in 2012 and led by Fermilab, connects expertise in nuclear material and accelerate targets to generate useful materials data for application within the accelerator and fission/fusion communities.
I will give an overview of the most recent activities within the framework of the RaDIATE collaboration.

Ponente: Frederique Pellemoine (FNAL)

RaDIATE collaboration update- CIEMAT meeting.pptx

9:30 IFMIF-DONES overview

IFMIF-DONES overview

Ponente: Philippe Cara

2024-09-16 Overview of the DONES Progarmme.pptx

10:15 → 10:50 Talks

10:15 Irradiation Capabilities of IFMIF-DONES and Future Research Opportunities

The IFMIF-DONES Facility will be a first-class scientific infrastructure situated in Granada, Spain. It will comprise an accelerator-driven neutron source capable of delivering ~1017 n/s with a broad peak at 14 MeV. The neutron source will be generated by impinging a continuous wave 125 mA, 40 MeV deuteron beam into a liquid Li jet target, circulating at 15 m/s and evacuating the 5 MW power of the beam. The primary scientific objective of IFMIF-DONES is the irradiation of specimens in a fusion-like neutron environment, essential for the material qualification of future fusion reactors like DEMO. Positioned a few millimeters downstream from the target, the material specimens will undergo irradiation under controlled temperatures ranging from 250 to 550 °C, with continuous monitoring of the radiation field (although other irradiation modules which could reach temperatures up to 1000 °C are also foreseen). The anticipated damage rate is within 20 dpa in 2.5 full power years for an irradiation volume of 300 cm³, and up to 50 dpa in 3 years for an irradiation volume of 100 cm³. Beyond its core mission of fusion materials qualifications, IFMIF-DONES will provide facilities for a diverse set of other experiments, making it a multidisciplinary neutron facility. These experiments span a wide spectrum of research fields, including, among others, medium flux fusion-related experiments (such as tritium breeders or fusion components validation), as well as many others non-fusion related, such as fast-neutron imaging, neutron time-of-flight, radioisotope production, or fundamental neutron physics research. This contribution will provide an overview of the project, highlighting its main requirements and technological challenges concerning the high-power target and irradiation modules operation and monitoring. Furthermore, it will provide a glimpse into the potential future nuclear research opportunities that extend beyond the fusion energy field.

Ponente: Dr. Claudio Torregrosa-Martin (IFMIF-DONES)

Irradiation Capabilities of IFMIF-DONES and Future Research Opportunities.pptx

10:50 → 11:20 Coffee Break

11:20 → 12:35 Talks

11:20 Overview of IFMIF-DONES Lithium Systems

IFMIF-DONES is a research facility designed to irradiate and qualify materials for future fusion reactors. At the core of the facility are the Lithium Systems, which generate an intense neutron flux (1-5$\cdot$10$^{14}$ n/cm$^2$s, with a broad peak at 14 MeV) through the interaction of a 40 MeV, 125 mA deuteron beam with a flowing liquid lithium target. The Lithium Systems consist of four key systems: the Target System, which generate a high-speed liquid lithium jet; the Heat Removal Loops, in charge of efficiently removing the heat deposition in the liquid lithium (5 MW); the Impurity Control System that minimizes corrosion and erosion phenomena and traps the impurities; and the Lithium System Ancillaries.

The Target System operates under extremely harsh conditions, including high radiation, high temperatures, and liquid lithium exposure. Among other challenges, these are: maintaining the stability and high velocity of the lithium jet, minimizing surface perturbations, and ensuring the lifetime of critical components like the backplate, which is subjected to severe irradiation damage ($\sim$25 dpa per full power year); operating in a high-radiation environment, requiring the development of specialized maintenance strategies in conjunction with remote handling technologies; and the selection and development of proper diagnostics. With a target's lifetime currently estimated at around 9 months, regular replacement strategies are required, supported by advanced remote handling technologies. The use of EUROFER-97 steel in the target helps reduce material activation (and radioactive waste) and improve its thermo-mechanical performance. Some preliminary studies propose using the target's material for Post-Irradiation Experiments (PIE), offering insights into material behavior under such conditions. This work summarizes the design and operational strategies of the Lithium Systems, highlighting the solutions implemented to meet these challenges.

Ponente: Jorge Maestre (IFMIF-DONES España)

IFMIF DONES target v1.pptx

11:45 Proton beam irradiation facility at J-PARC and activity on displacement damage study

For R&D of materials, especially beam intercept ones used in high-intensity proton beams, J-PARC plans to build a Proton Beam Irradiation facility using 400 MeV protons. A multi-purpose use for this facility, not only for material damage induced by the radiation but also Single Event Effects studies for semiconductor devices using proton and neutron and medical RI production, will be presented. Also, the activity of displacement damage study, in terms of studying displacement cross section, will be presented.

Ponente: Shin-ichiro Meigo (J-PARC/JAEA)

meigo_RaDIATE_cm2024_2.pdf

12:10 RaDIATE activities at J-PARC

J-PARC (Japan Proton Accelerator Research Complex) consists of a series of world-class proton accelerators and the experimental facilities that make use of the high-intensity proton beams. Recently, higher intense proton beams are requested due to requirement of further physics research. However, irradiation damage and thermal shock in the target, beam window, and other beam-intercepting components limit the beam intensity and the operation time in future facility. Research of material resistance to irradiation damage and thermal shock is an important issue common to all advanced accelerator facilities in the world. J-PARC officially participated in the international cross-disciplinary collaboration, RaDIATE, Radiation Damage In Accelerator Target Environments, in December 2017. So far, J-PARC has conducted the research mainly under collaboration with Fermi National Accelerator Laboratory by performing high-energy proton irradiation at Brookhaven National Laboratory, Post Irradiation Examination at Pacific Northwest National Laboratory, and thermal shock experiments at CERN-HiRadMat. Furthermore, consisting of experimental facilities such as Neutrino Experimental Facility, Hadron Experimental Facility, and Materials and Life Science Experimental Facility, accelerator facilities such as Linac, Rapid Cycle Synchrotron, and Main Ring, including Cryogenic Section, and Radiation Control Section, the entire J-PARC began to move as a project organized by the Director of J-PARC Center in April 2023. These activities also play an important role in the construction of the J-PARC proton beam irradiation facility. In this presentation, recent RaDIATE activities at J-PARC will be reported.

Ponente: Shunsuke Makimura (J-PARC, KEK)

J-PARC RaDIATE distribution2.pdf

12:35 → 13:00 Buffer

13:00 → 14:00 Lunch

14:00 → 15:15 Talks

14:00 FRIB Facility Status Update

The Facility for Rare Isotope Beams (FRIB) is a Department of Energy Office of Science (DOE-SC) User Facility, providing rare isotope beams to scientists to make discoveries about the properties of rare isotopes, nuclear astrophysics, fundamental interactions, and applications for society. The FRIB accelerator is a high-power superconducting linear accelerator which can accelerate ions up to uranium to energies of at least 200 MeV/u. Rare isotope beams are produced in a rotating graphite target and separated with an in-flight fragment separator. FRIB operations started in 2022 and the facility is currently commissioned to 10 kW primary beam power. A power increase to 20 kW is planned in fall of 2024.

Ponente: Andreas Stolz (MSU-FRIB)

Stolz_FRIB_FacilityStatusUpdate_RADIATE2024.pptx

14:25 Nuclear materials research at the University of Birmingham

In this talk, I will provide an update on nuclear materials research at the University of Birmingham including some recently development of the irradiation facility. This includes:
1) Research projects recently started on nuclear fission materials: Zircaloys
2) R&D in fusion energy materials: RAFM steels, plasma facing materials.
3) Irradiation facility update: End-station development

Ponente: Prof. Yu-Lung Chiu (University of Birmingham)

RaDIATE_2024_YLC_V1.pptx

14:50 Post irradiation examination techniques for characterization of highly irradiated components at the Spallation Neutron Source

Radiation-induced effects in materials can alter the microstructure and mechanical properties of structural materials, typically resulting in a degradation of the ductility and fracture toughness. Characterization and understanding of the microstructural changes and deformation processes that occur in irradiated materials are critical for preventing failure and ensuring reliable operation of components in high-radiation environments. At the Spallation Neutron Source (SNS) located at Oak Ridge National Laboratory (ORNL), a post irradiation examination (PIE) program is maintained to sample and test material from targets and proton beam windows (PBW) after their removal from operation. Sampling and testing of these materials is complicated by their high levels of radioactivity. The complications from examining and testing irradiated material has led to the development of specialized characterization techniques designed to protect the researcher and provide useful information. These techniques typically involve using reduced-size specimens or special handling techniques to limit the exposure to personnel. Several unique materials characterization techniques have been developed at ORNL to test and examine radioactive specimens, including digital image correlation (DIC), in-situ tensile tests with a scanning electron microscope equipped with an electron backscattered diffraction (SEM-EBSD) detector, thermal desorption spectroscopy (TDS), differential scanning calorimetry (DSC), and scanning transmission electron microscopy with electron energy-loss spectroscopy (STEM-EELS). This presentation will cover the characterization techniques developed and used at ORNL to characterize irradiated material samples from the SNS PIE program.

Ponente: David McClintock (Oak Ridge National Laboratory)

15:15 → 15:45 Coffee Break

15:45 → 17:15 Talks

15:45 Insights into radiation resistance of titanium alloys from displacement cascade simulations

Radiation damage in beam window materials limits the use of high-power proton beams in high-energy physics research. Currently, the alloy Ti-6Al-4V is used, but Ti-15V-3Cr-3Sn-3Al has been proposed as an alternative. We compared radiation damage in the α and β-phases of these alloys through primary knock-on atom (PKA) cascade simulations in the 10-40 keV energy range using molecular dynamics (MD). At PKA energies of 30 and 40 keV, Ti-6Al-4V's β-phase produces nearly twice as many Frenkel pairs as Ti-15V-3Cr-3Sn-3Al's β-phase. The α-phase of both alloys outperforms their β-phases in terms of damage and surviving defects. The average displacement threshold energy (Ed) is 66 eV in the α-phase for both alloys, 55 eV in the β-phase of Ti-15V-3Cr-3Sn-3Al, and 46 eV in the β-phase of Ti-6Al-4V. Although both alloys show similar numbers of surviving defects, their vacancy and interstitial clustering mechanisms differ, affecting radiation hardening and ductility. Our simulations suggest that Ti-6Al-4V forms larger vacancy and interstitial clusters, making it a promising candidate for beam window materials with higher radiation tolerance.

Ponente: Ankit Roy (PNNL)

16:10 LANSCE Activity Overview

LANSCE Activity Overview

Ponente: Tarik Saleh

Radiate-Saleh-LA-UR-24-29877.pdf

16:35 Low Energy Proton and Helium Beam Irradiation and Post Irradiation Examination Plan for the Study of Second Target Station Beam Interception Materials

The rotating water-cooled tungsten target which is being developed for the second target station (STS) project at Oak Ridge National Laboratory (ORNL) is in its preliminary design phase. The spallation volume of the target consists of tungsten plates which are diffusion bonded to each other with tantalum interlayer. The spallation volume is encapsulated with edge-cooled structural shell made of Inconel 718. The Inconel shell is diffusion bonded to the spallation volume using hot isostatic pressing with a layer of thermal interface material OFHC copper. The lifetime of the target is largely determined by radiation damage characteristics of tungsten, tantalum, Inconel 718 and OFHC copper. While there are materials data and operational records of tungsten, tantalum, and Inconel 718 in spallation environments, the corresponding data of proton and spallation neutron irradiated copper is scares. To study the radiation damage properties of copper in STS beam conditions, which is characterized by a high helium production rate of about 40 appm per year in copper, a low energy proton irradiation campaign followed by helium beam irradiation has been being performed at the Michigan Ion Beam Laboratory. Low energy proton/helium beams below the Coulomb barrier of copper does not activate the sample which enables post irradiation examination (PIE) in a normal lab environment while simulating similar beam conditions to high energy beam on the target in view of He-appm/dpa ratio. The PIE of irradiated copper will be focused on studying helium induced swelling and temperature dependent embrittlement of copper. In this talk, we present an overview of the irradiation campaign program and plan for the PIE. The data will be used to predict the radiation induced swelling rate and loss of ductility in the copper thermal interfacing layer in the STS target, which will help optimizing the target design that can accommodate the identified radiation induced effects. Also, planned future low energy proton beam irradiation campaign for studying selected beam intercepting materials for STS is presented.

Ponente: Yong Joong Lee (ORNL)

RaDIATE-9_Yong_Joong_Lee_2024.pptx

19:00 → 20:00 The dinner will be at the hotel Barceló Carmen Granada Please arrange your transportation to the hotel before 8:00PM. Address: Barceló Carmen Granada, C. Acera del Darro, 62, Centro, 18005 Granada, Spain

20:00 → 22:30 Welcome Dinner at Restaurant Barceló Carmen Granada.

The dinner will at the hotel Barceló Carmen Granada
Please arrange your transportation to the hotel before 8:00PM.
Address: Barceló Carmen Granada, C. Acera del Darro, 62, Centro, 18005 Granada, Spain

martes, 17 de septiembre

9:00 → 10:40 Talks

9:00 CIEMAT Hot cells project for DONES samples

The construction of the IFMIF-DONES facility in Escúzar (Granada) must be accompanied by the qualification at CIEMAT of a facility capable of handling and analyzing structural and functional materials irradiated with neutrons.
Since these irradiated samples can reach very high levels of activity (of the order of tens of TBq), it is imperative to use adequate shielding and security systems to be able to carry out their analysis.
At present, there is no facility in Madrid nor in Spain, equipped to handle material of this level of radioactivity and capable of conducting the required studies. These include mechanical properties and microstructural studies of intensely irradiated material in IFMIF-DONES in the case of structural material and optical and electrical properties in the case of insulators.
The construction of the hot cells facility at CIEMAT will allow this center to enter the list of European facilities that will benefit directly from the scientific results derived from the operation of the IFMIF-DONES accelerator in Spain.
Being the site of the neutron source for the study of fusion materials, it is essential to have the capacity for Spanish science to benefit directly from the study of irradiated material.
The probable site at Ciemat has already been determined and a detailed study of the condition of the building is underway.
Progress is also being made on the design of the required hot cells incorporating all the technological advances for the efficient and safe processing of activated samples.
This includes designs in terms of shielding, safety procedures and protocols, and the necessary instrumentation for structural (steel) and functional (insulation) material analysis.
This work will present the current status and future goals of the facility.

Ponente: Rafael Vila (CIEMAT)

VILA_RADIATE_HotCells_2024.pptx

9:25 Investigation of radiation damage of fine-grain graphite for target applications

Fine- and medium-grained nuclear grade graphite materials have been used as low-Z secondary particle production targets in large-scale neutrino experiments. Irradiation induced dimensional change as well as thermo-mechanical changes in these materials have been identified as a limiting factor in their lifetime. Therefore, it is essential to develop a mechanistic understanding of irradiation damage and its correlation with bulk properties to inform future target material selection. This sets the horizon of this PhD work. Specifically, a set of preliminary neutron diffraction measurements at the ENGINX beamline (ISIS Neutron & Muon Source) have been carried out on an ex-service unfractured NT02 POCO-ZXF5Q to acquire the distribution of strains as a function of irradiation damage. The position and broadening of the basal plane diffraction peaks have been analysed and will be reported. A follow-up experiment has been planned to collect spectra with better signal to noise ratio and to investigate areas away from the proton beam centre, i.e., subject to less beam damage. In addition, for accelerated irradiation experiment on next generation graphite target materials, He+ ion irradiation capabilities have been identified at Surrey Ion Beam Centre. HOPG, POCO, together with IG510U, IG430U, IG110 and G347A will be irradiated with 2 MeV He+ at 500oC for three fluences: 4.5×1017 ions/cm2, 7.5×1016 ions/cm2 and 2.3×1016 ions/cm2. These materials will subsequently be studied by Transmission electron microscopy (TEM), nanoindentation and Time-domain Thermo-reflectance (TDTR); the results will be correlated with Raman and XRD measurements of crystalline differences between irradiated and unirradiated graphite.

Ponente: Alex Comyn

AComyn_RADIATE_presentation.pptx

9:50 Innovative experimental approaches to understand microstructural defect evolution during irradiation under high-temperature and mechanical strain

The development of advanced experimental setups capable of simulating the harsh conditions of a fusion reactor is crucial for the future of nuclear materials research. Currently, the scientific community is making significant efforts to understand the complex mechanisms underlying the relationship between irradiation damage, mechanical stress, and high temperature when applied simultaneously. This synergy is expected to influence the evolution of microstructural defects such as dislocation loops, swelling, and chemical segregation. To explore these effects, a versatile experimental device has been designed and implemented at CIEMAT, allowing the simultaneous application of mechanical deformation and high-temperature irradiation for a variety of materials. Initial trials using high-purity Fe specimens, subjected to deformation under Fe ion irradiation at 20 MeV and at temperatures of up to 450°C, have shown distinct microstructural arrangements, particularly at elevated temperatures, with and without applied stress. This setup is also ideal for investigating small-scale specimens, which is especially relevant for ongoing research in the DONES (Demo-Oriented Neutron Source) project.

Given the complexity of studying these phenomena, high-purity Fe was chosen as a model material to minimize pre-existing microstructural features that could affect defect evolution. The results of these experiments will not only enhance our understanding of the potential synergies between deformation, irradiation, and temperature but also provide critical data to support future computational models. These models aim to predict the behavior of materials exposed to such extreme environments, bridging the current gap between real microstructures in advanced structural steels and those that can be simulated using existing computational tools. Ultimately, this research is of great interest to the Nuclear Fusion Community, offering valuable insights for developing materials capable of withstanding the severe conditions expected in future fusion reactors.

Ponente: Marcelo Roldán Blanco (CIEMAT)

M Roldan Radiate - CIEMAT.pptx

10:15 Ab initio study of cementite – α-Fe interfaces under irradiation

One of the materials that will be investigated in the IFMIF-DONES facility is EUROFER97, a reduced activation ferritic/martensitic (RAFM) steel and the European reference steel for the First Wall and the Breeding Blanket of DEMO.
It is now well-established that defects generated under neutron irradiation strongly affect mechanical properties, and thus, the material’s performance [1]. In particular, while C impurities [2,3] significantly influence point-defect evolution in Fe-based alloys, many aspects of the mechanisms governing the arrangement of C atoms in a bcc-Fe lattice remain unclear. Our objective is to explore the configuration adopted by C in the presence of cementite, a common carbide that precipitates in steels. To achieve this, we utilize Density Functional Theory (DFT) calculations and Molecular Dynamics simulations (MD).
Our primary focus lies on the bcc-Fe – Cementite (α/θ) interface. On one hand, understanding the behavior and properties of cementite is crucial, as carbides can emit C atoms, which can alter the evolution of defects generated during irradiation. On the other hand, it is also essential to determine how radiation defects interact with the cementite into the Fe matrix, in particular whether the cementite/Fe interface can act as a sink as how this would affect their evolution.
In this study, we construct the α/θ interface based on two orientation relationships (ORs): the Bagaryatskii OR and a structure that takes a ferrite orientation typical of the grain boundary Σ5(310) and a cementite orientation that minimizes misfit: (001), (110) and (1-10). We investigate the effects of strain, the various possible terminating planes, and the relative in-plane positions to determine the most stable structures using MD simulations. Subsequently, these energetically favorable structures are downscaled for DFT, and the interfacial energy is recalculated.
Point defects are introduced to examine their influence on the interface energy. Specifically, we explore the stability of cementite and the conditions under which C atoms are emitted into the Fe matrix: migration paths and whether or not they are trapped.

Ponente: Pablo Canca López (Universidad de Granada)

pablo_canca_radiate_2024.pptx

10:50 → 11:20 Coffee Break

11:20 → 12:30 Talks

11:20 Assessment and comparison of EUROFER97 transmutation in IFMIF-DONES and DEMO

The mission of the International Fusion Materials Irradiation Facility-DEMO Oriented NEutron Source (IFMIF-DONES) is to test materials under equivalent nuclear fusion irradiation conditions and doses to be qualified for the future fusion power plant DEMO.
Transmutation calculations are essential for understanding how radiation can affect materials. Therefore, a comparison of transmutation in IFMIF-DONES and DEMO is crucial. For this reason, transmutation calculations have been performed for EUROFER97 material samples in the High Flux Test Module (HFTM) and in the first wall of DEMO. For IFMIF-DONES has been considered a specimen material in the first line of the beam in rig 45 inside the HFTM, using different beam energies 25, 30, 35 and 40 MeV. For DEMO data has been considered three blanket concepts in the Eurofusion roadmap, such as Dual Coolant Lithium Lead (DCLL), Water Cooled Lithium Lead (WCLL) and Helium Cooled Pebble Bed (HCPB).

Ponente: Irene Álvarez Castro (University of Granada)

IAlvarez_9RADIATE.pptx

12:05 Towards a Standardised Methodology of Radiation Damage Defect Distributions for Microstructure Evolution Models

In the context of material irradiation simulations, we have developed a model that combines the results from Molecular Dynamics (MD) and the Binary Collision Approximation (BCA) to reconstruct the damage produced by an irradiated ion of any energy of interest. Our tool, which will be available for the community, is aimed to provide a standardised way of introducing defects in larger scale models. Our code takes the energy and position of the primary knock-on atoms (PKAs) along the ion track from SRIM [1] and combines it with a database of MD cascade debris (CascadesDB [2]) of single PKA calculations to obtain the total damage produced. For the lowest energies, the full energy range arc-dpa model [3] is used to compute the number of Frenkel pairs generated. We also implemented two methods, for defect and cluster identification, respectively. The former is required to extract the cascade debris from the full simulation box given in the database used, while the latter can be used either to analyse the database or to find the cluster distribution produced by an ion. In addition, the output given by our program can be used as an input for larger scale models, like Object Kinetic Monte Carlo or Cluster Dynamics. Although we have focused our developments on ion irradiation, our code could be extended to simulate neutron or any other particle irradiation, as long as the energies and positions of the PKAs are given.

[1] http://srim.org/
[2] https://cascadesdb.iaea.org/
[3] Qigui Yang and Pär Olsson, Phys. Rev. Materials 5, 073602 (2021)

Ponente: Abel Carlos Gutiérrez Camacho (Universidad de Alicante)

a_c_gutierrez_camacho.odp

a_c_gutierrez_camacho.pdf

12:30 → 13:00 Buffer

13:00 → 14:00 Lunch

14:00 → 15:40 Talks

14:00 Machine Learning Interatomic Potentials for Fusion Oriented Materials

Machine Learning Interatomic Potentials (MLIAPs) mix the accuracy of ab initio methods such as Density Functional Theory (DFT), with the scalability of classical interatomic potentials. Fusion structural materials, employed in the construction of future fusion reactors, experiment high neutron radiation doses. This radiation disturbs the crystal structure, generating defects in the lattice. To better understand the formation and dynamics of these defects in the crystal, we present a MLIAP based on the equivariant neural network MACE [1]. Using this potential, we are able to characterize the formation and binding energies of the most common defects in an iron crystal using a reduced database with only some simple defects. The trained potential accurately reproduces the dumbbell defect energy drop in the <110> direction, characteristic of ferromagnetic bcc iron. We also include a top layer with a Ziegler-Biersack-Littmark (ZBL) screened nuclear repulsion potential in order to perform Primary Knock-on Atom simulations (PKA), giving the potential the capability of study neutron collision cascades.

References

[1] I. Batatia, D. P. Kovacs, G. N. C. Simm, C. Ortner and G. Csanyi. MACE: Higher order equivariant message passing neural networks for fast and accurate force fields, Advances in Neural Information Processing Systems, (2022)

[2] Barouh, Caroline, et al. "Interaction between vacancies and interstitial solutes (C, N, and O) in α− Fe: From electronic structure to thermodynamics." Physical Review B 90.5 (2014)

[3] Fu, Chu-Chun, François Willaime, and Pablo Ordejón. "Stability and mobility of mono-and di-interstitials in α-Fe." Physical review letters 92.17 (2004)

Ponente: Pedro Julián Delgado Galindo (Consorcio IFMIF-DONES España)

Machine Learning Interatomic Potentials for fusion oriented materials.pptx

14:25 Novel materials for high-power accelerator components

As beam power continues to increase in next-generation accelerator facilities, high-power target systems face crucial challenges. Components like beam windows and particle-production targets must endure significantly higher levels of particle fluence. The primary beam’s energy deposition causes rapid heating (thermal shock) and induces microstructural changes (radiation damage) within the target material. These effects ultimately deteriorate the components’ properties and lifespan. With conventional materials already stretched to their limits, we are exploring novel materials including High-Entropy Alloys and Electrospun Nanofibers that offer a fresh approach to enhancing tolerance against thermal shock and radiation damage. This talk will provide an update on our efforts to develop these novel materials.

Ponente: Kavin Ammigan (Fermi National Accelerator Laboratory)

RaDIATE2024_KA.pptx

14:50 Computational Exploration of High Entropy Alloys as Promising Materials for Future Beam Windows

Beam power and runtime in high energy particle accelerators are currently limited by targets and beam windows. The existing materials used in these components have reached their maximum potential, necessitating the development of a new class of materials known as high entropy alloys (HEAs) to overcome this challenge. Numerous studies have demonstrated that HEAs possess exceptional qualities such as high strength, ductility, and radiation resistance. In this study, we propose an approach that utilizes computational techniques including CALPHAD, density functional theory (DFT), and molecular dynamics (MD) to investigate and comprehend the defect properties of suitable HEAs, which can serve as alternative materials for the next generation of beam windows. Initially, CALPHAD is employed to conduct approximately one hundred thousand simulations, enabling us to narrow down the potential compositions to a select few. Data has been gathered using DFT based approach for training a machine learning model and first version of the machine learned inter-atomic potential has been developed. Developed inter-atomic potential are now being used to study the defect properties using molecular dynamics and monte-carlo methods. During this presentation, I will outline the CALPHAD approach implemented to refine the compositions, elucidate the need of DFT, and demonstrate the potential usefulness of machine learning in this context.

Ponente: Gaurav Arora (Postdoc Research Associate)

Radiate2024.pptx

15:15 → 15:45 Coffee Break

15:45 → 16:35 Talks

15:45 Multiphysics Simulations of Nanofibrous High Power Targets for the Inference of Failure Modes

Fermilab’s High Power Targetry Research and Development (HPT R&D) group have been developing and studying an electrospun nanofiber target concept to support the need for robust targets in future fixed target facilities. These nanofiber mats have demonstrated resistance to radiation damage, and the free motion of the individual fibers is expected to mitigate the cyclic stresses induced by a pulsed, high-power beam. To evaluate the efficacy of this concept, nanofiber mat samples have been sent by the HPT R&D group to the HiRadMat facility at CERN for prototypic thermal shock testing; the outcomes of these experiments show that the survivability of a nanofiber target depends on its construction parameters, in particular the packing density of the fibers. Samples with higher packing densities have consistently been destroyed by exposure to the HiRadMat beam, with a hole at the beam center visible, and layers of nanofibers “peeled” away from the center hole, whereas samples with lower densities have survived with limited damage.

The exact reason for the failure of the higher density targets was unclear at the time of the original experiments, but the results of our recent multiphysics simulations which recreate the experiments support the hypothesis that the expansion and pressurization of the air inside the target after being heated by the pulsed beam is the cause; in a high density nanofiber mat, the motion of air through the pores of the mat is much more restricted, and induces a larger pressure on the fibers, blowing the mat apart. In this talk, we’ll share the results of these simulations and discuss how they support this hypothesis.

Ponente: William Asztalos (Illinois Institute of Technology and Fermilab)

SuperCombo.mp4

WJA_RaDIATE_2024.pptx

16:10 Challenges and opportunities for the thermal interface selection and diffusion bonding in the STS target segment

The target assembly for the Second Target Station (STS) at Oak Ridge National Laboratory is working towards final design approval in late 2025, and R&D continues to focus on the manufacturing of the target segments. The novel design of the target segment and unique combination of materials has driven the process development towards solid state bonding techniques (vacuum hot pressing (VHP) and hot isostatic pressing (HIP)). The mismatch in thermal expansion between the tungsten core and Inconel shroud, combined with the wedge-shaped geometry, create challenges for material interface bonding. A copper thermal interface layer creates a robust bond with both tungsten and Inconel, but copper has a low irradiation swelling temperature range. The lower bound of this range (estimated from literature) is close to the upper bound of the predicted operating temperature range of the copper in the target segment. Therefore, alternative thermal interface layers are also being investigated. The preliminary bonding results will be presented along with the manufacturing development results for the tungsten-copper-Inconel design.

Ponente: Justin Mach (Oak Ridge National Laboratory)

RaDIATE-9_Justin_Mach_2024.pptx

16:35 → 17:35 Council Member Meeting - Closed session

20:30 → 21:30 Please arrange your transportation to the Alhambra to arrive at 9:30 at the entrance.

21:30 → 23:00 Night Guided-Visit to Alhambra

miércoles, 18 de septiembre

9:00 → 10:40 Talks

9:00 In-situ observation of deformation mechanisms in fine-grained nuclear graphite by high temperature disc compression

Evaluating structural integrity requires knowledge of the distribution of, and relationship between, stress and strain as well as how the microstructure accommodates damage. New candidate graphites possess different microstructures to previous grades; there is a need to validate materials understanding on these new graphite grades, as well as collect data at relevant temperatures for materials qualification. In this work, small Brazilian disc specimens of fine grained graphite (diameter 5 mm) were loaded in diametral compression at elevated temperatures whilst observed in-situ using Synchrotron X-ray radiation on beamline i12 at the UK Diamond Light Source. Temperatures of 800 °C were achieved via resistance heating. Elastic strains and bulk strains were measured pseudo-simultaneously via transmission-diffraction mapping and digital image correlation of radiographs respectively. The spatial correlation of these strains has been used to investigate the deformation behaviour in compression and tension, including non-linear effects due to tensile damage mechanisms. A change in crystallographic texture with strain was also quantified via the Bacon Anisotropy Factor. The observed effects of temperature and strain provide new insights into the crystal deformation mechanisms of graphite microstructures. Demonstrating the viability of this experimental method for testing small scale samples also constitutes an important first step in building a testing regime suitable for investigating damage tolerance in irradiated material at elevated temperatures.

Ponente: James Marrow (University of Oxford)

9:25 Study of Thermal Requirements in the HFTM using Finite Element and Monte Carlo Simulations.

The International Fusion Materials Irradiation Facility - DEMO Oriented NEutron Source (IFMIF-DONES) is a neutron irradiation facility designed to provide critical material irradiation data for the construction of DEMOnstration fusion power plants. The present work focuses on examining the thermal requirements of the High Flux Test Module (HFTM) from a reliability analysis perspective. To achieve this, a numerical tool, which combines Finite Element discretizations and Monte Carlo techniques, has been formulated and coded. This tool allows us to calculate the probability of failure of the thermal requirements, taking into account uncertainties in nuclear heating and the quantification of complex thermal properties.

Ponente: José Miguel Palomino Cobo (UGR)

RadiatePowerPoint-3.pdf

9:50 Dynamic Thermomechanical Simulations of IFMIF-DONES Target’s Back-Plate failure

IFMIF-DONES is a radiological facility designed to irradiate material samples under irradiation conditions similar to those expected in future fusion reactors. For this purpose, high energy neutrons are produced by an intense 40 MeV deuteron accelerator directed towards a target made of a 25 mm thickness liquid Li curtain circulating at 25 m/s, depositing a nominal power of 5 MW which is evacuated with the Li. The Back-Plate is the part of the Target Vacuum Chamber placed just downstream the Li, separating the vacuum of the accelerator and target chambers and the low-pressure He atmosphere in the Test Cell, where the irradiation modules with the materials specimens will be placed. In this context, one of the most critical accident scenarios postulates an eventual loss of liquid lithium curtain thickness without shutting down the beam, leading to a direct or partial deuteron beam impact on the Back-Plate with the consequent large power deposition into it. The present work provides a dynamic thermomechanical study of the Back-Plate response in this event, aiming at characterizing the involved timings in the impact-triggered events, such as mechanical failure due to thermal stresses, melting or vaporization. This is important to evaluate the eventual mobilisation of the Back-Plate volatilized activated material through the accelerator vacuum chambers and the available timings for both active Safety Beam Shutdown or even a "passive" shutdown due to vacuum loss in the chambers. The methodology consists in obtaining power deposition data by means of Monte-Carlo simulations (SRIM) and loading them into a Finite Element model of the Back-Plate in ANSYS to perform transient thermal and structural analyses. The results include a set of timings for melting, vaporization, and mechanical failure as function of the beam footprint area and the lithium curtain thickness reduction.

Ponente: Manuel Antonio Vázquez Barroso (IFMIF-DONES Granada)

RaDIATE_presentation_09-24.pptx

10:15 Developments on RaDIATE-related R&D for CERN's Beam Intercepting Devices

The presentation will cover the developments that have taken place on post-irradiation examination activities that have taken place at CERN since the last collaboration meeting. Specifically:
• Design and execution of the HiRadMat-HLTDE experiment
• Execution and preliminary results of the HiRadMat-SMAUG2 experiment for high-brightness proton beam windows
• Upgrade of the HiRadMat dump and lessons learnt
• Upcoming PIE of two spent Antiproton Decelerator Targets

Ponente: Nicola Solieri

2024-09-18+RaDIATE+CM+NSv1.pptx

10:50 → 11:20 Coffee Break

11:20 → 12:40 Talks

11:20 Simulating Radiation Damage in ISIS Targets

ISIS TS2 targets consistently require replacement only ~1.5 years into their nominally 5-year design lifetime. The achievable life is limited by increasing activation of the cooling water, thought to be due to tungsten in direct contact with water. The cause of these issues has been a long-standing mystery.
Recent advances have been made in understanding radiation damage effects on tungsten, and incorporating these into detailed FEA simulations. This offers a possible explanation for the observed issues which is consistent with the target lifetimes we have experienced. This raises the possibility that such failures could be predicted and avoided in future. The same analysis method has now been applied to ISIS TS1 targets to confirm that there are no issues expected.
When designing future targets, e.g. for an ISIS-II facility, it will be important to take account of radiation damage effects and prior target operating experience. The proposed approach to setting appropriate design limits for future ISIS targets will be discussed.

Ponente: Dan Wilcox (UKRI-STFC)

RaDIATE 2024 - Simulating Radiation Damage in ISIS Targets - Final.pptx

11:45 Nuclear-grade Graphite as Target Material for High Energy Physics Applications

Nuclear-grade graphite plays the role of neutron moderator, reflector and structural in High Temperature Gas-cooled Reactors (HTGRs) and two Generation IV reactor designs including Very High Temperature Reactors (VHTRs) and Molten Salt Reactors (MSRs). They also serve as production targets in large proton beamlines at Fermilab ((LBNF), Rutherford Accelerator Laboratory (ISIS and Muon Source), CERN (beam dump) and Japan Proton Accelerator Research Complex (T2K). There is an increasing demand of gaining better understanding of the evolution of nuclear graphite’s thermal and mechanical properties with irradiation to underpin the selection and design of target system for next generation MW-class accelerators. This talk will describe the challenges of nuclear graphite materials in the context of High Energy Physics and will present a range of experimental results including quantification of the microstructure, irradiation damage and the relevant thermal and mechanical properties using advanced experimental techniques. The data will be compared with those medium-grained graphite used in current nuclear fission reactors.

Ponente: Dong (Lilly) Liu (University of Oxford)

12:10 RaDIATE Material Groups kickoff meeting

We would like to create several sub-groups in the RaDIATE collaboration to focus and share information about material use in High Power Targetry. the 3 first groups would be on Ti-alloys, W-alloys and C.
this meeting is to initiate the discussion to organize the group and define how we will work together.

Sub group discussion.pptx

12:40 → 13:00 Buffer

13:00 → 14:00 Lunch

14:00 → 15:00 Talks: Closing session

14:00 Closing session

Ponente: Frederique Pellemoine (FNAL)

closing session.pptx

14:45 → 17:30 Visit: Visit to IFMIF-DONES Site in Escúzar