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Simulation of deuterium trapping in tungsten. Tommy Ahlgren Kalle Heinola Mathias Groth Jari Likonen. 5 keV D implantation in W High flux, low energy D irradiation (JET). 1. Multiscale modeling. DFT (Density Functional Theory) MD (Molecular Dynamics Simulations)
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Simulation of deuterium trapping in tungsten Tommy Ahlgren Kalle Heinola Mathias Groth Jari Likonen • 5 keV D implantation in W • High flux, low energy D irradiation (JET) 1
Multiscale modeling DFT (Density Functional Theory) MD (Molecular Dynamics Simulations) KMC (Kinetic Monte Carlo) RE (Rate Equations) 2
Rate Equations (RE) • Continuum theory • Theory of sink strengths • Transition state theory T. Ahlgren, K. Heinola, K. Vörtler, and J. Keinonen, Journal of Nuclear Materials 427 (2012) 152
Rate Equations (RE) Events not including hydrogen (H) Events with H
Parameters to RE DFT RE MD KMC Hydrogen binding energies in W monovacancy EXP DFT RE
5 keV D implantation in W Sample: • Polycrystalline p-W (Plansee) • C impurity concentration ~ 1019 /cm3 • O impurity concentration ~ 5x1018 /cm3 • Cold worked samples (dislocation density 108–1012/cm2) Experimental: Room temperature implantation (1800 s) Fluence: 5.8x1016 D/cm2 D profiles by SIMS and NRA
MD: 5 keV D irradiation induced defects 0.23 Vacancies and SIAs / Implanted D
RE: Simulation of defect and D profiles Matsui et al. JNM 283-287 (2000) 1139 10 keV D (sc-W) G = Grain boundary R = Dislocation C = Carbon impurity atom
RE: Simulation of defect and D profiles • D binding energy to dislocations and grain boundaries (MD DFT) • D binding energy to C and O impurities (DFT)
High flux, low energy D irradiation (JET fusion experiment) Sample: Polycrystalline W Experimental: ~6 s JET pulse with ELMs RE Simulation: 1) D flux from sample to plasma 2) Total D retention in sample
High flux, low energy D irradiation (JET fusion experiment) Inter ELM ~ 18 eV ELM ~ 100 eV
High flux, low energy D irradiation (JET fusion experiment)
High flux, low energy D irradiation (JET fusion experiment) 1) D flux from sample back to plasma 2) Total D retention in sample
High flux, low energy D irradiation (JET fusion experiment) 1) D flux from sample back to plasma 2) Total D retention in sample