Upcoming seminars

Seminars at DIFFER cover a wide range of topics and are held on Thursdays at 11.15 AM in the seminar room of the institute (unless otherwise stated). Seminars are open to everybody. If you are interested in visiting a DIFFER seminar or want to subscribe to our mailing list, please follow the instructions for external visitors.

List all past seminars organized at DIFFER

Juergen Rapp
September 25th 2018
11:15 to 12:15
Note the different day of the week. The availability of future fusion devices such as a Fusion Nuclear Science Facility (FNSF) or DEMO greatly depends on long operating lifetimes of plasma facing components in their divertors. ORNL is designing the Material-Plasma Exposure eXperiment (MPEX), a superconducting magnet, steady state device to address the plasma material interactions of fusion reactors. MPEX will utilize a new high-intensity plasma source concept based on RF technology. This source concept will allow the experiment to cover the entire expected plasma conditions in the divertor of a future fusion reactor. It will be able to study erosion and re-deposition for relevant geometries with relevant electric and magnetic fields in-front of the target. The source system consists of a helicon antenna for high density plasma production. The electrons are heated by microwaves either with 28 GHz EBW, or 105 GHz with 2nd harmonic X-mode ECH. 105 GHz Upper Hybrid collisional damping is explored as well. Ions are heated in the 7-9 MHz ICRF range via a magnetic beach approach. The total heating power will be up to 800 kW. MPEX is being designed to allow for the exposure of a-priori neutron-irradiated samples. In this concept, targets will be irradiated in ORNL’s High Flux Isotope Reactor (HFIR) or possibly at the Spallation Neutron Source (SNS) and then subsequently (after a sufficiently long cool-down period) transferred to MPEX and exposed to fusion reactor relevant plasmas. The pre-design of MPEX will be presented. MPEX is being developed in a staged approach with successively increased capabilities. After the initial development step of the helicon source and ECH system the source concept is being tested in the Proto-MPEX device (100 kW helicon, 200 kW EBW, 30 kW ICRH). Results from the plasma source development on Proto-MPEX will be presented.
Marius Wirtz
September 27th 2018
11:15 to 12:15
Plasma facing materials (PFMs) in a fusion device like ITER/DEMO have to withstand severe environmental conditions such as high thermal loads and particle fluxes. These exposure conditions may cause a deterioration of the heat removal capability of the material and/or component. In order to ensure that designs of plasma facing components are suitable for an application under such exposure conditions detailed qualification programs are required. Especially the high steady state and transient thermal loads, simulated with electron/laser beams and linear plasma devices, induce a wide range of surface modifications and damages on the PFM surface as well as in the component. Important issues are the performance of materials under high cycle transients, after/during neutron irradiation, after recrystallization, and under simultaneous particle fluxes (D/T/He).
Wilson Smith
October 18th 2018
11:15 to 12:15
abstract will follow
Peter Zijlstra
November 8th 2018
11:15 to 12:15
abstract will follow