Status and Update of the RaDIATE Collaboration R&D Program - PowerPoint PPT Presentation

FERMILAB-SLIDES-17-010-AD Status and Update of the RaDIATE Collaboration R&D Program Kavin Ammigan (Fermilab) on behalf of the RaDIATE Collaboration 13 th International Topical Meeting on Nuclear Application of Accelerators 3 rd August 2017 This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics

Outline o High power targets: scope and challenges o Research focus of the RaDIATE collaboration o Ongoing and future R&D activities of RaDIATE o Summary 2 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

High Power Targetry Challenges o Major accelerator facilities have recently been limited in beam power not by their accelerators, but by their target facilities (SNS, NuMI/MINOS) o Even greater challenges are present for future high power and high intensity target facilities o To maximize the benefit of high power accelerators (physics/$), challenges must be addressed in time to provide critical input to multi-MW target facility designs 3 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

High Power Targetry Scope R&D needed to support: Targets Collimators (eg. 100 TeV pp collimators) o o Solid, Liquid, Rotating, Rastered o Facility requirements o Other production devices o Remote handling o Collection optics (horns, solenoids) Shielding and Radiation Transport o o Monitors & Instrumentation Air Handling o o Beam windows Cooling System o o Absorbers o 4 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

High Power/Intensity Targetry Challenges Heat removal Thermal shock Subjects of the RaDIATE Collaboration Physics performance Radiation damage Operational safety Storage and disposal At the Proton Accelerators for Science and Innovation Workshop (PASI 2012), workshop participants from a range of high power accelerator facilities identified radiation damage and thermal shock as the most cross-cutting challenges facing high power target facilities 5 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Thermal Shock (Stress Waves) Example: T2K beam window Material response dependent on: Specific heat (temperature jump) Dynamic stress waves may result in o o plastic deformation, cracking, and fatigue Coefficient of thermal expansion (induced strain) o Modulus of elasticity (associated stress) o Flow stress behavior (plastic deformation) o Strength limits (yield, fatigue, fracture toughness) o Heavy dependence on material properties, but: material properties dependent upon Radiation Damage 6 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Radiation Damage Disorders Microstructure Microstructural response: Creation of transmutation products o Atomic displacements (cascades) o Displacements Per Atom (DPA) = o Average number of stable interstitial/vacancy pairs created From D. Filges, F. Goldenbaum, in:, Handb. Spallation Res., Wiley-VCH Verlag GmbH & Co. KGaA, 2010, pp. 1–61. 7 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Radiation Damage Effects 3.2 DPA 0 DPA Displacements in crystal lattice (expressed as Displacement Per Atom, DPA) Embrittlement o Creep o Swelling o Fracture toughness reduction o 23.3 DPA 14.9 DPA D.J. Porter and F.A. Garner, J. Nuclear Thermal/electrical conductivity reduction o Materials, 159, p. 114,1988 Coefficient of thermal expansion o S. A. Malloy, et al., Journal of Nuclear Modulus of Elasticity Material, 2005. (LANSCE irradiations) o Accelerated corrosion o Transmutation products o He, H gas production can cause void o formation and embrittlement (appm/DPA) Factor of 10 reduction Very dependent upon material and in thermal conductivity at 0.02 DPA irradiation conditions (eg. temperature, dose rate) N. Maruyama and M. Harayama, “Neutron irradiation effect on … graphite materials,” Journal of Nuclear Materials, 195, 44-50 (1992) 8 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Neutrino HPT R&D Materials Exploratory Map 1.0E+16 NuMI-MINOS Target LBNF-DUNE - 2 Thermal Shock Severity (p/cm 2 /pulse) NT-02 (damaged) 1.0E+15 T2K First Target NuMI-NOvA Target TA-01 (MET-01) 1.0E+14 LBNF-DUNE - 1 1.0E+13 SNS range for 1.4 MW operation for 1 continuous year Service Future 1.0E+12 1.0E+20 1.0E+21 1.0E+22 1.0E+23 Radiation Damage Severity (damage equivalent fluence, p/cm 2 ) 9 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

R a D I A T E Collaboration Radiation Damage In Accelerator Target Environments radiate.fnal.gov Broad aims are threefold: to generate new and useful materials data for application within the accelerator and  fission/fusion communities  to recruit and develop new scientific and engineering experts who can cross the boundaries between these communities  to initiate and coordinate a continuing synergy between research in these communities, benefitting both proton accelerator applications in science and industry and carbon-free energy technologies Currently adding CERN and J-PARC to the MOU 10 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

HE proton irradiations to explore candidate target/window materials 85 BNL BLIP Irradiation 1 (2010) 0.056DPA 75 0DPA 65 181 MeV proton irradiation o 0DPA 300 C Anneal Stress (MPa) 55 4 graphite grades exposed to 6e20 p/cm 2 o 0.056DPA 290 C Anneal Changes in material properties (30-50%) o 45 Annealing (> 150 °C) achieves partial o 35 recovery 25 Confirmed choice of POCO ZXF-5Q (least o 15 change in critical properties) 5 0 0.2 0.4 0.6 0.8 Irradiation at higher temperatures may be o Strain (%) beneficial. However, Diffusion assisted effects are increased o (swelling from He bubble formation, creep) Increased oxidation rate o Degraded thermal shock resistance o 11 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

HE proton irradiations to explore candidate target/window materials BNL BLIP Irradiation 2 (2017-2018) Phase 1 completed, Phase 2 to start in early 2018 o Total of 8-week irradiation o Includes various grades of different materials: o Be & C (FNAL) o Fatigue Tensile & Bend specimens Microstructural specimens Ti & Si (FRIB, KEK, FNAL, U. of Oxford, STFC) o specimens Al (ESS) o Ir, TZM, CuCrZr (CERN) o Most PIE work will be performed at PNNL o Mesoscale fatigue HiRadMat specimens specimens 12 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Examination of irradiated Be beam window indicates fracture toughness changes under irradiation NuMI Be window (Kuksenko, Oxford) PIE of Be window exposed to 1.57e21 o protons Advanced microscopy techniques ongoing o Li matches MARS predictions and remains o 0.47 DPA homogeneously distributed at ~50 °C 0.24 DPA Crack morphology changes at higher dose o Transgranular to grain boundary o fracture Recent and future work with Be (2017) Micro-mechanical testing o Micro-cantilever o Nano-indentation o Preliminary results indicate significant hardening o and increase in effective elastic modulus 13 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Ion implantation of Be indicates significant hardening at low DPA He implantation at Surrey/Oxford (Kuksenko, Oxford) NuMI 0.5 dpa, 2000appm, He, 50C PF60(VHP) – 0.1 dpa, 2 MeV He+ ions: 7.5 µm penetration o 2000appm of He, 50C depth NuMI 0.1 dpa, 400appm Dose: up to 0.1 DPA o He, 50C Temperature: 50 °C and 200 °C o Nano-indentation shows significant o PF60-rolled, as-rec hardening at 0.1 DPA and 50 °C Future work with He in Be (2017-2018) Micro-cantilever testing o Higher dose and temperature irradiations o EBSD map Nano-indentation 14 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17

Radiation-induced swelling a possible cause of failure of NuMI NT-02 graphite target NT-02 graphite target autopsy (FNAL, PNNL) Graphite fin exposed to 8e21 p/cm 2 o Evidence of bulk swelling from o micrometer measurements of fins More swelling in US fin locations o More swelling in fractured fins o TEM BF TEM BF Evidence of fracture during operation o Symmetric fracture structure o Limited impurity transport into whole o fins relative to fractured fins Evidence of limited radiation damage o and material evolution Surface discoloration appears to be o mostly solder and flux material Crystal structure and porosity o • Taken from fracture surface at the center where the beam was targeted consistent with as-fabricated • Lamella has mixed regions of what appear to be amorphous (yellow insert conditions diffraction pattern) and nanocrystalline microstructure (red square) • Mrozowski cracks at the interfaces between these two regions 15 7/11/2018 K. Ammigan | Status and Update of the RaDIATE Collaboration R&D Program | AccApp’17