Properties of boron carbide ceramics made by various methods for use in ITER

The results of a study of the chemical composition, vacuum and thermal properties of boron carbide ceramics, which is planned to be used in ITER diagnostic ports, are presented. The measured boron carbide content in sintered and hot pressed ceramics is 99,0÷99,7%, they do not contain unauthorized impurities, which in accordance to ITER requirements. The outgassing rate of sintered and hot pressed boron carbide produced by Virial Ltd meets the requirements of the ITER Vacuum Handbook. Sintered ceramic is cheaper than hot pressed, and it is produced in large volumes, which it would be preferable for use in ITER ports, but with its massive use may create a significant gas load on the vacuum system that requires accurate analysis and outgassing tests on all candidated ceramics.