Modelling of JET and ITER reactor relevant plasma neutron source for neutronics calculation chain

Research output: ThesisDoctoral ThesisCollection of Articles

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Abstract

It is essential for the research of reactor relevant plasmas to understand how heat transfer is affected by the properties of and phenomena in the plasma fuel. The major part of heat is transferred out via energetic neutrons. The neutrons must be taken into account as a heat source as well as from the perspective of material activation and induced reactions. In simulations the calculation chain from the reactants to products, heat transfer and material effects requires the coupling methods in plasma physics, reactor analysis and thermohydraulics calculation. This thesis focuses on reactor relevant plasmas. The first part discusses plasma operational scenarios concentrating especially on advanced tokamak scenarios. The time evolution of the safety factor q is strongly connected to total plasma current and confinement, so the data analysis based on the identity plasma experiments is extended with predictive current diffusion simulations. A sensitivity test with respect to typical plasma parameters carried out for time evolution of q and internally generated bootstrap current density. The second and third parts consider fusion products and their characterisation. The simulation tool AFSI fusion source integrator is presented and validated using JET tokamak data. The production rate and neutron spectrum is calculated in a geometry which correspond to real diagnostics based on the experimental data. Additionally, the results have been compared qualitatively to the experimental measurements when with good agreement between calculated and measured values. In the fourth part, the calculation chain from the modelling of plasma fuel to the balance-of plant modelling is described with the focus on the coupling of plasma physics and neutronics. As a demonstration case, the predictions ITER plasma data and a CAD model have been used. AFSI has been coupled to the ASCOT particle following code, which defines the distribution and energy of the reactants. A neutron source was provided for a dose-rate calculation with the Serpent code, which is available for a further coupling to thermohydraulics.

Details

Original languageEnglish
QualificationDoctor's degree
Awarding Institution
Supervisors/Advisors
Publisher
  • Aalto University
Print ISBNs978-952-60-8046-8, 978-951-38-8651-6
Publication statusPublished - 2018
MoE publication typeG5 Doctoral dissertation (article)

    Research areas

  • plasma physics, magnetic confinement, scenario modelling, fusion neutrons, synthetic diagnostics

ID: 32206455