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

Research output: ThesisDissertationCollection of Articles

Abstract

It is essential for the research of reactor relevant plasmas to understand how heat transfer isaffected by the properties of and phenomena in the plasma fuel. The major part of heat istransferred out via energetic neutrons. The neutrons must be taken into account as a heat sourceas well as from the perspective of material activation and induced reactions. In simulations thecalculation chain from the reactants to products, heat transfer and material effects requires thecoupling methods in plasma physics, reactor analysis and thermohydraulics calculation.
This thesis focuses on reactor relevant plasmas. The first part discusses plasma operationalscenarios concentrating especially on advanced tokamak scenarios. The time evolution of the safetyfactor q is strongly connected to total plasma current and confinement, so the data analysis basedon the identity plasma experiments is extended with predictive current diffusion simulations. Asensitivity test with respect to typical plasma parameters carried out for time evolution of q andinternally generated bootstrap current density.
The second and third parts consider fusion products and their characterisation. The simulationtool AFSI fusion source integrator is presented and validated using JET tokamak data. Theproduction rate and neutron spectrum is calculated in a geometry which correspond to realdiagnostics based on the experimental data. Additionally, the results have been comparedqualitatively to the experimental measurements when with good agreement between calculatedand measured values.
In the fourth part, the calculation chain from the modelling of plasma fuel to the balance-ofplantmodelling is described with the focus on the coupling of plasma physics and neutronics. Asa demonstration case, the predictions ITER plasma data and a CAD model have been used. AFSIhas been coupled to the ASCOT particle following code, which defines the distribution and energyof 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.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Aalto University
Supervisors/Advisors
  • Tuomisto, Filip, Supervisor, External person
Award date19 Jun 2018
Publisher
Print ISBNs978-952-60-8046-8, 978-951-38-8651-6
Electronic ISBNs978-952-60-8047-5, 978-951-38-8650-9
Publication statusPublished - 2018
MoE publication typeG5 Doctoral dissertation (article)

Fingerprint

neutron sources
reactors
thermohydraulics
plasma physics
fusion
heat transfer
neutrons
heat
plasma control
theses
plasma currents
neutron spectra
integrators
concentrating
products
computer aided design
simulation
activation
current density
dosage

Keywords

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

Cite this

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title = "Modelling of JET and ITER reactor relevant plasma neutron source for neutronics calculation chain: Dissertation",
abstract = "It is essential for the research of reactor relevant plasmas to understand how heat transfer isaffected by the properties of and phenomena in the plasma fuel. The major part of heat istransferred out via energetic neutrons. The neutrons must be taken into account as a heat sourceas well as from the perspective of material activation and induced reactions. In simulations thecalculation chain from the reactants to products, heat transfer and material effects requires thecoupling methods in plasma physics, reactor analysis and thermohydraulics calculation.This thesis focuses on reactor relevant plasmas. The first part discusses plasma operationalscenarios concentrating especially on advanced tokamak scenarios. The time evolution of the safetyfactor q is strongly connected to total plasma current and confinement, so the data analysis basedon the identity plasma experiments is extended with predictive current diffusion simulations. Asensitivity test with respect to typical plasma parameters carried out for time evolution of q andinternally generated bootstrap current density.The second and third parts consider fusion products and their characterisation. The simulationtool AFSI fusion source integrator is presented and validated using JET tokamak data. Theproduction rate and neutron spectrum is calculated in a geometry which correspond to realdiagnostics based on the experimental data. Additionally, the results have been comparedqualitatively to the experimental measurements when with good agreement between calculatedand measured values.In the fourth part, the calculation chain from the modelling of plasma fuel to the balance-ofplantmodelling is described with the focus on the coupling of plasma physics and neutronics. Asa demonstration case, the predictions ITER plasma data and a CAD model have been used. AFSIhas been coupled to the ASCOT particle following code, which defines the distribution and energyof 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.",
keywords = "plasma physics, magnetic confinement, scenario modelling, fusion neutrons, synthetic diagnostics",
author = "Paula Siren",
year = "2018",
language = "English",
isbn = "978-952-60-8046-8",
series = "Aalto University Publication Series: Doctoral Dissertations",
publisher = "VTT Technical Research Centre of Finland",
number = "118/2018",
address = "Finland",
school = "Aalto University",

}

Modelling of JET and ITER reactor relevant plasma neutron source for neutronics calculation chain : Dissertation. / Siren, Paula.

VTT Technical Research Centre of Finland, 2018. 126 p.

Research output: ThesisDissertationCollection of Articles

TY - THES

T1 - Modelling of JET and ITER reactor relevant plasma neutron source for neutronics calculation chain

T2 - Dissertation

AU - Siren, Paula

PY - 2018

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N2 - It is essential for the research of reactor relevant plasmas to understand how heat transfer isaffected by the properties of and phenomena in the plasma fuel. The major part of heat istransferred out via energetic neutrons. The neutrons must be taken into account as a heat sourceas well as from the perspective of material activation and induced reactions. In simulations thecalculation chain from the reactants to products, heat transfer and material effects requires thecoupling methods in plasma physics, reactor analysis and thermohydraulics calculation.This thesis focuses on reactor relevant plasmas. The first part discusses plasma operationalscenarios concentrating especially on advanced tokamak scenarios. The time evolution of the safetyfactor q is strongly connected to total plasma current and confinement, so the data analysis basedon the identity plasma experiments is extended with predictive current diffusion simulations. Asensitivity test with respect to typical plasma parameters carried out for time evolution of q andinternally generated bootstrap current density.The second and third parts consider fusion products and their characterisation. The simulationtool AFSI fusion source integrator is presented and validated using JET tokamak data. Theproduction rate and neutron spectrum is calculated in a geometry which correspond to realdiagnostics based on the experimental data. Additionally, the results have been comparedqualitatively to the experimental measurements when with good agreement between calculatedand measured values.In the fourth part, the calculation chain from the modelling of plasma fuel to the balance-ofplantmodelling is described with the focus on the coupling of plasma physics and neutronics. Asa demonstration case, the predictions ITER plasma data and a CAD model have been used. AFSIhas been coupled to the ASCOT particle following code, which defines the distribution and energyof 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.

AB - It is essential for the research of reactor relevant plasmas to understand how heat transfer isaffected by the properties of and phenomena in the plasma fuel. The major part of heat istransferred out via energetic neutrons. The neutrons must be taken into account as a heat sourceas well as from the perspective of material activation and induced reactions. In simulations thecalculation chain from the reactants to products, heat transfer and material effects requires thecoupling methods in plasma physics, reactor analysis and thermohydraulics calculation.This thesis focuses on reactor relevant plasmas. The first part discusses plasma operationalscenarios concentrating especially on advanced tokamak scenarios. The time evolution of the safetyfactor q is strongly connected to total plasma current and confinement, so the data analysis basedon the identity plasma experiments is extended with predictive current diffusion simulations. Asensitivity test with respect to typical plasma parameters carried out for time evolution of q andinternally generated bootstrap current density.The second and third parts consider fusion products and their characterisation. The simulationtool AFSI fusion source integrator is presented and validated using JET tokamak data. Theproduction rate and neutron spectrum is calculated in a geometry which correspond to realdiagnostics based on the experimental data. Additionally, the results have been comparedqualitatively to the experimental measurements when with good agreement between calculatedand measured values.In the fourth part, the calculation chain from the modelling of plasma fuel to the balance-ofplantmodelling is described with the focus on the coupling of plasma physics and neutronics. Asa demonstration case, the predictions ITER plasma data and a CAD model have been used. AFSIhas been coupled to the ASCOT particle following code, which defines the distribution and energyof 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.

KW - plasma physics

KW - magnetic confinement

KW - scenario modelling

KW - fusion neutrons

KW - synthetic diagnostics

M3 - Dissertation

SN - 978-952-60-8046-8

SN - 978-951-38-8651-6

T3 - Aalto University Publication Series: Doctoral Dissertations

PB - VTT Technical Research Centre of Finland

ER -