Speaker
Description
The use of a liquid metal in the plasma-facing divertor components of the DEMO project has attractive properties such as self-healing and neutron resilience and a liquid metal handling system is considered as a candidate technology. The linear plasma device Magnum-PSI is capable of producing DEMO-relevant plasma fluxes which well replicate expected divertor conditions. The present research is focused on creating a prototype to demonstrate the feasibility of the liquid metal circulation through a plasma loaded target under a relevant plasma flux at Magnum-PSI. The system uses liquid tin as a cooling agent. The Sn pumping technology for this has recently been developed by Ushio and BLV Licht for a repetitively pulsed Sn-plasma based 13.5 nm Extreme UV (EUV) source. It is currently employed by TNO in the EBL2 nanolithography research facility where the liquid tin flow removes the 10 kW heat flux from the electrodes of the EUV source. For plasma facing experiments in a linear plasma device a prototype is proposed consisting of an electromagnetic liquid metal pump with a water-vapor cooled heat exchanger dissipating up to 30 kW. The system further consists of a heated pipeline to transmit liquid tin through the vacuum and open air parts of the setup as well as through the plasma loaded target installed in the DIFFER Magnum-PSI system. System design and operation requirements are analyzed and discussed based on the existing experience of the liquid tin based EUV sources and on the requirements to be met for the Magnum-PSI machine.
