Gas trapping and surface analysis study of boron film deposited using Ortho-Carborane

Plasma material interaction plays a crucial role in tokamak experiments. Trapping and recycling of fuel atoms due to plasma material interaction on first wall has significant impact on effective fuel control. Boronization is used on tokamak devices to reduce impurity release and to achieve effective fuel control. Objective of present work is to study the characteristics of boron film, deposited using ortho-carborane (O-C₂B₁₀H₁₂) in hydrogen glow discharge, in terms of its composition as well as trapping and release of different gas species. XPS study of the de-convoluted B 1s peak of boron deposited on molybdenum substrates reveals that B-O and B-C bonding is present in the film. Boronized wall shows 2.59 mbarliter/sec/m² of thermal desorption of hydrogen after it was exposed to hydrogen background for few hours. It is observed that 19.07 mbarliter/sec/m² of hydrogen is pumped when boronized surface is exposed to hydrogen glow discharge and 5.78 mbarliter/sec/m ² of hydrogen is release when glow discharge is switched off. Details of experimental set up, procedure and analysis is given in this paper