The DEMO in-vessel plasma facing components, like the breeding blanket FW and the divertor, are subject to high heat fluxes (HHF) due to radiation and high energetic particles colliding to these PFCs. Most of the current cooling concepts (at least the reference ones) rely on the cooling channels embedded into the plasma-facing wall or, in case of divertor, cooling pipes with a W-armor. Because the wall heat flux is applied only from one side (plasma facing side), the heat transfer area is limited only to a (small) portion of the pipe circumference with consequences on the cooling requirements. One efficient way of increasing the heat transfer area would be to use heat pipes. Taking advantage of their high conductivity, vastly superior to any metal, the surface heat from the plasma facing side can be transported into the cooling fluid, where, due to the design of the heat-pipe condenser, the heat transfer to the coolant can be optimized in such a way that the local heat flux remains well below the critical values. Using heat pipes between the main coolant and the plasma introduces also an additional safety feature, a failure of the plasma facing side having as an effect the release of a limited quantity of water into the vacuum chamber, the integrity of the coolant circuit is not affected.

The objective of the PhD is to investigate the possibility of using water-based heat pipes for DEMO divertor. The work will focus, in a first phase, on the dimensioning of a heat pipe, that should be capable of dealing with typical peak heat fluxes as high as 20MW/m2 and, at the same time, can operate properly at lower heat fluxes (1MW/m2) that are characteristic to the areas far from the strike point. Among other things, one major challenging task in this context will be to investigate different alternatives for the heat pipe’s capillary structure because of their decisive influence on the internal heat transport performance. In order to establish the operating performances and limits of the concept, in a second phase, a mock-up of the selected heat pipe concept will be manufactured and tested in one of the HHF facilities available at KIT.

The work will be done in collaboration with University Stuttgart, Institute of Nuclear Technology and Energy Systems (www.ike.uni-stuttgart.de), which has an extensive experience in heat pipes with applications in nuclear fission and other thermomechanical fields.

Personal qualification

You have a diploma/master degree in mechanical engineering, , physics or similar qualification, and have a strong interest in research.

You are fluent in English.

Good knowledge of fluid dynamics, thermal hydraulics and numerical simulation. Experience in experimental activities, the use of ANSYS/CFX, COMSOL or similar codes as well as knowledge of fusion technology is considered as an advantage.

Organizational unit

Institute for Neutron Physics and Reactor Technology (INR)

Starting date


Contract duration

limited to 3 years

Application up to


Contact person in line-management

For further information, please contact Dr. Ghidersa, phone 0721 608-23764, E-Mail: bradut-eugen.ghidersa@kit.edu


Please apply online using the button below for this vacancy number 15-2018-INR.
Personnel Support is provided by

Mr Barny
Telefon: +49 721 608-25029,

Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

We prefer to balance the number of female and male employees. Therefore we kindly ask female applicants to apply for this job.

If qualified, handicapped applicants will be preferred.





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