JET ITER-like wall - overview and experimental programme
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Citations
Predicting disruptive instabilities in controlled fusion plasmas through deep learning
Plasma-surface interaction in the Be/W environment: Conclusions drawn from the JET-ILW for ITER
Overview of the JET results in support to ITER
Plasma operation with an all metal first-wall: Comparison of an ITER-like wall with a carbon wall in JET
Tungsten transport in JET H-mode plasmas in hybrid scenario, experimental observations and modelling
References
Tritium inventory in ITER plasma-facing materials and tritium removal procedures
Overview of the ITER-like wall project
Status and physics basis of the ITER divertor
An ITER-like wall for JET
Type-I ELM power deposition profile width and temporal shape in JET
Related Papers (5)
Plasma-surface interaction in the Be/W environment: Conclusions drawn from the JET-ILW for ITER
Plasma operation with an all metal first-wall: Comparison of an ITER-like wall with a carbon wall in JET
Fuel retention studies with the ITER-Like Wall in JET
Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall
Frequently Asked Questions (16)
Q2. What is the priority for establishing a reference database?
re-establishing H-modes at similar power levels to those with the carbon walls is a priority for establishing a reference database.
Q3. Why did the ALARP principle mean that manual work was kept to a minimum?
Due to the radiation level inside JET resulting from activation of the Inconel vacuum vessel, the ALARP principle has meant that manual work has had to be kept to a minimum.
Q4. What is the main concern of the paper?
Here the concern is thatsignificant mobilisation of molten material could potentially swamp the intrinsic migration due to intrinsic sputtering which is a key part of the baseline migration and fuel retention picture for ITER.
Q5. How many Sv/hr were used to move the task modules into the vessel?
The task modules were then moved into the vessel using a series of pre-programmed moves which have an accuracy of about 1cm, the tiles and tools are handled by the MASCOT manipulator which is manually operated and has force feedback.
Q6. What is the aim of the new programme?
The aim here is to build up sufficiently thick deposits / fuel inventory that surface analysis will be capable of resolving them and link them to a specific ITER-relevant scenario.
Q7. What was the main purpose of the ITER-like Wall?
the ITER-like Wall was designed to avoid exposure of beryllium tile edges with step sizes over 40µm in high heat flux areas [Thompson] by shaping / shadowing by adjoining tiles [nunes].
Q8. What are the thermal limits of the ITER-like Wall?
The thermal limits are most fundamentally driven by relatively low melting point of beryllium (1356ºC), the robustness of tungsten coatings to slow [maier] and fast [thomser] thermal cycles and support structures for the bulk tungsten tile [mertens].
Q9. How many Sv/hr were used to load the task modules?
Personnel working inside the enclosure in pressurised suits would then populate the drawers of the task modules with tools and components as required by the plan.
Q10. How many Sv/hr was needed to deliver components to the place of work?
The efficiency of the in-vessel work also relied heavily on development of a second long remote handling boom (Octant 1) capable of delivering "Task Modules" loaded with tools and components to the place of work so the MASCOT manipulator on the existing JET boom (Octant 5) could work efficiently.
Q11. Why did the main limiters have a lower temperature rise than the thin CFC slices?
The main limiters on the low field side of the machine (wide poloidal limiters) have optimised large format tiles and therefore lower temperature rise for a given power density than the thin CFC slices which they replaced [nunes].•
Q12. How many Sv/hr was the total output of the ITER-like Wall?
The scope of the call was defined by the following headlines:1. Characterisation of the ITER-like Wall 1.1 Fuel retention and material migration 1.2 Material limits and long term samples 1.3 Transient and steady state power loads 2. Exploration of ITER operating scenarios with the ITER-like Wall 2.1 Develop plasma scenarios 2.2 Assess plasmas scenarios 2.3 Explore scenarios in domains closest to ITER dimensionless parameters 3. Physics issues essential to the efficient exploitation of the ILW and ITER 3.1 Divertor and Scrape-Off Layer physics 3.2 Confinement, pedestal and ELM physics 3.3 Disruptions, MHD and fast particle physics 3.4 Diagnostic issues for ITERIn selecting the proposals for execution in 2011/12 considerable weight was given to the most urgent priorities for ITER for which the new wall materials and other upgraded JET capabilities would have the greatest impact.
Q13. How many task forces have been involved in the experiments?
Although there have always been specific themes the campaigns the experiments have been carried out by up to 7 distinct task forces who worked to a large independently and compete for machine time.
Q14. How many tasks were carried out in the JET?
Following a call to the EURATOM Fusion Associations participating in JET, 205 experimental proposals were discussed and consolidated following a second general planning meeting in November 2010 attended by representatives of the Associations, the European Commission and ITER into 52 main experiments and 37 parasitic experiments.
Q15. What was the average speed of the JET-like Wall?
Previous JET experimental campaigns following shutdowns began with a restart/commissioning phase where the machine systems are brought close to full performance followed by a phase of scientific exploitation.
Q16. How many components could be handled without addition mechanical support?
A limit of 10kg was set on the weight of components which could be handled without addition mechanical support (e.g. 100kg winch).