First study of lithium boron composite as plasma facing material

Abstract

Lithium-Boron Composite Material (LBCM) is presented as a plasma-facing material with a lot of promise from the perspective of liquid metal first wall. LBCM consists of ∼ 20 w.% boron and ∼ 80 w.% lithium, arranged in the form of a Li5B4 matrix filled with metal lithium, similar to capillary porous systems (CPS) already used as plasma-facing elements. The characteristic matrix cell size is approximately 5 µm. LBCM was subjected to electron flux and helium plasma in a linear PR-2 device. LBCM maintained physical integrity up to T > 900 °C. Boron didn’t evaporate from LBCM under electron irradiation, but was sputtered during helium bombardment. CPS-like properties, wherein Li from the whole of the LBCM sample was transported to the area of the highest thermal load were observed.

Keywords

• Plasma facing materials
• First wall
• Lithium
• Boron
• Composite materials