Postdoc PMI

Scientific aim:

The design of the ITER divertor has been finalized and manufacturing of the European inner target has now commenced. What is still unclear is the expected performance of the divertor targets under the varying normal and transient loading conditions during ITER operation which are still subject to a large uncertainty. Additionally the topics of performance of irradiated materials and how well the ITER solution can be extrapolated for a demonstration power plant are receiving greater and greater prominence. The scientific focus of the community has therefore shifted to 1) understanding the lifetime and required plasma conditions to maximise this lifetime of the ITER plasma facing components 2) performance of tungsten which has been damaged (irradiated, cracked, melted) to define a clear lifetime limit and 3) development of advanced tungsten grades with improved properties for longer lifetime.

Research:

Your role will be to plan and carry out experiments and characterize tungsten materials, both standard grade and advanced, under different loading conditions using the unique DIFFER PSI facilities, in particular our flagship MAGNUM-PSI device. The tasks could include several or all of the following:

• Determination of crack-growth propagation from pre-damaged tungsten
• Evaluation of enhanced surface erosion and re-deposition of pre-damaged tungsten
• Very high cycle number surface fatigue of tungsten monoblocks and material characterization thereof.
• Performance evaluation of advanced tungsten grades under high flux loading conditions

As well as carrying out the above tasks your responsibilities would be to also support the research of PhDs within the PMI group and of visiting researchers to the DIFFER PSI devices using your expertise, and to act as daily supervisor for one or more masters students.

Projectcoordinator

De projectcoördinator maakt deel uit van het team Finance and Control. Het Team Finance and Control is o.a. verantwoordelijk voor kwaliteitsborging en ondersteuning van subsidie- en projectaanvragen. Als projectcoördinator ben je verantwoordelijk voor het ondersteunen van de onderzoekers bij projectaanvragen en contractzaken en het coördineren van projecten. Je richt je o.a. op de volgende taken:

Je adviseert en instrueert onderzoekers over nationale en internationale subsidieprogramma's, zoals NWA en Horizon Europe.

Je coördineert alle NWO & Horizon Europe subsidies die worden aangevraagd of die zijn toegekend, maar bijvoorbeeld ook regionale samenwerkingsprogramma's.

Je richt in en onderhoudt interne en externe projectadministraties, waaronder EC Participant Portal en ISAAC. Hierbij werk je intensief samen met je andere collega's van de afdeling Finance&Control.

Je beoordeelt en adviseert over o.a. grant-, project-, consortium-, en non disclosure agreements. Waar nodig stel je zelf een overeenkomst op of win je juridisch advies in.

Je onderhoudt, samen met de andere teamleden, een netwerk van interne en externe belanghebbenden

Technisch Medewerker

Vanuit het team Facility Management draag je bij aan het (laten) uitvoeren van onderhoud aan en van het hoogwaardige (Breaam-gecertificeerde) DIFFER gebouw. Tevens biedt de technisch medewerker ondersteuning bij de inrichting van de (gebouwgebonde) technische infrastructuur. De technisch medewerkers werken binnen het team Facility Management samen met medewerkers van de keuken en receptie. Daarnaast wordt er veel samengewerkt met partijen die diverse installaties beheren en in onderhoud hebben.

Een technisch medewerker bij DIFFER plant, regelt, onderhoudt en inspecteert werktuigbouwkundige installaties (luchtbehandeling, CV installaties, waterleidingen, koelinstallaties, liften, etc.) en procesinstallaties (elektra, beveiligingsinstallaties, noodstroomvoorziening, gebouwenbeheerssysteem, perslucht- en gasleidingnetten, brandblusmiddelen, etc.); Afhankelijk van expertise worden taken verdeeld en/of uitbesteed. De medewerker heeft kennis van de veiligheidsnormen (NEN 1010, NEN 3140, NEN 3840) en heeft affiniteit/ervaring met het PLANON. Kennis van Autocad is een pre.

Bij modificatie van installaties en in overleg met interne opdrachtgevers stel je een programma van eisen op en doe je hierbij voorstellen ter verbetering van installaties. Onderhoudsklussen pak je zelf op of je selecteert een partij om het uit te laten voeren. Je bewaakt als toezichthouder de voortgang, kwaliteit, het budget en de planning van de door externen uit te voeren werkzaamheden. Je beantwoordt vragen van en informeert medewerkers en externe technische dienstverleners. Je verricht storingsdiensten, interpreteert meldingen en neemt passende actie.

PhD Plasma aided conversion of nitrogen/oxygen into nitric oxides

In this project plasma aided conversion of nitrogen/oxygen in to nitric oxides is investigated in a microwave induced plasma flow reactor. Key issues will be fundamental understanding of the plasma physics and chemistry at play in connection the energy cost and conversion efficiency of the N₂/O₂ mixture. Plasma diagnostics such as optical emission spectroscopy and Raman spectroscopy, spatially and time resolved are need to be developed and employed. In this project, we aim to develop the reduced plasma chemical model of the flow reactor to further enhance the performance. Alternative configurations, such as forward and reverse configurations will be investigated as well as alternative plasma sources.

The new PhD student is asked to fulfil following tasks:

PhD position Simulation of pellet fueled tokamak reactor regimes

Tokamak reactors must fueled by cryogenic pellets. In addition, there is much evidence of pellet fueling playing a role in improved plasma confinement regimes. Fast and accurate modelling of pellet scenarios with integrated models would help understand and optimize these regimes. In addition, this modelling capability would benefit answering control-oriented questions such as fueling, burn, and exhaust control in pellet scenarios where incidents such as missing pellets can occur. This PhD position focuses on building up such capabilities for the JINTRAC multiphysics tokamak simulation suite¹ , and then tackling the underlying research question of understanding and predicting pellet-enhanced confinement regimes. While JINTRAC, using first-principle-driven transport models, has been shown to accurately model pellet fueled scenarios², the optimization and control-oriented nature of this project demands fast modelling and thus the extension of neural network surrogate models implemented within JINTRAC³. Experimental validation of the modelling pipelines will be carried out on existing data of a target tokamak to be determined (possibly ASDEX-Upgrade). To enable the research, the following tools must be developed.

• A fast surrogate pellet ablation and fueling model, using neural networks, of the HPI2 model
• Fast surrogate turbulence model valid for target tokamak regimes
  • Development of the QuaLiKiz neural network tailored to pellet scenarios on the target tokamak, using Active Learning techniques for data efficiency
  • Collecting a profile database of the target tokamak for sampling inputs for the NN training.
• Coupling the new surrogate models for JINTRAC "flight simulator" fast modelling
• Large-scale validation of JINTRAC + fast surrogate models in target tokamak pellet regimes
• Scenario optimization of pellet enhanced scenarios