PhD Code: 2016-DC-02:
- Host institute 1: AM07-Aix- Marseille Université (Home University) - FP8-Institut de Recherche sur la Fusion par confinement magnétique, Saint-Paul-lez-Durance, France (Home Institution)
- Host institute 2: FP4-Universidad Carlos III de Madrid (Host University) - AM04-ITER Organization (Host Institution)
- F1. Tokamak physics for ITER and beyond
- Prof. Dr. Sadruddin Benkadda (promotor)
- Prof. Raul Sanchez (co-promotor)
- Dr. Alberto Loarte (mentor)
- Dr. Xavier Garbet (mentor) Dr. Clarisse Bourdelle (co-mentor)
- Dr. Jonathan Citrin (mentor)
Operation of tokamaks with high Z plasma facing components raises issues regarding the control of high Z impurities in the confined plasma, necessary to avoid excessive radiative losses. Present studies of tungsten (W) transport in ITER with gyrokinetic and gyrofluid codes indicate that the transport of W in the central part of ITER plasmas is expected to be governed by neoclassical transport. Therefore the prediction of the transport processes that determine the density and temperature gradients for the D and T ions in the central core region of ITER plasmas is of key importance to determine the core behaviour of W in this region. In addition, these transport processes are expected to be modified by the heating and current drive schemes applied to the ITER plasmas which, together the resulting alpha particle heating, can then be used to control them and to affect W transport and prevent its possible accumulation.
Study the implications of core anomalous plasma transport on core W-accumulation in ITER, and mechanisms for its control. Gyrokinetic codes will be applied, which contain the physics describing anomalous plasma transport. This determines the density and temperature profiles expected in the central plasma region of ITER. This then sets the level of neoclassical W transport. A range of plasma scenarios will be studied, including the specific features of ITER fuelling and heating systems. This will be accomplished through three intermediate objectives:
First objective. Identify the physics processes dominating the residual turbulent transport level in the core region of ITER plasmas. Determine the appropriate modelling approaches, i.e. flux driven models or gradient driven models in open-loop iteration with global transport codes.
Second objective. Using the modelling approaches identified in the first objective, perform systematic studies to determine the anomalous transport level in the core plasmas for a range of plasma conditions in ITER scenarios. Before performing these systematic studies, the predictions of the model will be compared with results from existing tokamak experiments, with central plasma conditions as close as possible to those expected in ITER (i.e. infrequent sawteeth, low core fuelling source, low plasma toroidal rotation). The output of the systematic studies are predictions of the core density and temperature profiles, set by anomalous transport, for a range of plasma conditions typical of ITER scenarios and with various heating and fuelling schemes.
Third objective. Following the predictions outlined in the second objective, evaluate the implications on core neoclassical W transport using the NEO code.
Time line and mobility scheme (research need to be performed for at least six month in two different countries):
1st year (October 2016-September 2017):
Months 1-9: IRFM and AMU, France:
- Introduction to modelling of turbulent plasma transport and associated modelling approaches.
Months 10-12: Universidad Carlos II de Madrid, Spain:
- Analysis of modelling approaches to be applied to ITER modelling.
2nd year: (October 2017-September 2018):
Months 1-4: IRFM and AMU, France:
- Adoption of modelling approach to be applied to the ITER modelling to be carried out during the PhD.
Months 5-9: ITER Organization and IRFM, France:
- Comparison of the model predictions with experimental results and first systematic application of modelling approach chosen to ITER high Q plasma scenarios. Learning of the application of NEO to core W transport modelling in ITER.
Months 10-12: Universidad Carlos III de Madrid, Spain:
- Analysis of results and refinement of modelling approaches if required.
3rd year (October 2018-September 2019):
Months 1-12: ITER Organization and IRFM, France:
- Completion of modelling of core ITER plasmas for reference plasma scenarios (including DT low Q plasmas and He plasmas)
- Application of NEO to model core W transport in ITER reference plasma scenarios.
- Finalizing PhD thesis writing.
In addition or complementary to the mobility scheme above, the student may be required to spend periods at DIFFER, The Netherlands, as required for the progress of the PhD project.
Original document: 2016-DC-02