The first objective is focused on the development of the experiments both for the extraction through a free-surface and through a permeable membrane. During the last few years, the effectivity of using a membrane as extraction interface has been questioned within the fusion community. An experiment to determine if the membrane acts as a true ‘catalyzer’ of the permeation process enhancing the extraction of H-isotopes from the liquid metal is being prepared. For that, two different extractors have already been manufactured: one with a vanadium membrane and the other with flowing PbLi directly exposed to vacuum. The comparison between both approaches will be performed in a dedicated experimental campaign in CLIPPER.
CLIPPER counts with all components needed to perform the experiments at relevant breeding blanket conditions (temperature 300 - 550 ℃; mass flow rates 2 - 39 kg/s): electromagnetic pump, Gas Injection System, Gas Extraction System (PAV with and without membrane), heating and control systems. The objective is divided into two phases:
- O1.1 – Membrane-based permeation against vacuum The activity is focused on the experimental operation of CLIPPER while a membrane-based-PAV is installed. This extractor is based on a rectangular chamber divided in two parts by an horizontal membrane of vanadium with 1 mm thickness. The PbLi flows in the bottom channel and vacuum is performed in the upper channel. The PbLi-solubilized hydrogen permeates through the membrane and the vacuum system carries it to a quadrupole mass spectrometer for its detection.
- O1.2 – Free-surface permeation against vacuum experiments In a similar way, the extraction under vacuum could be performed in the absence of a permeable membrane, exposing the liquid metal directly to the vacuum chamber. A rectangular cross-section channel for PbLi flowing is defined in order to expose a flat face to vacuum. The extractor consists of a vacuum chamber with connections to the PbLi circuit, the vacuum system and some nozzles for control of liquid metal level with sensors on the top of the extractor. The solubilized hydrogen reaches the surface and recombines, and the vacuum system carries it to a quadrupole mass spectrometer for its detection.
