Using double-fluid theory, a microwave absorption coefficient of cold hydrogen plasma in CNTs, which were grown by iron-catalyzed high-pressure disproportionation （HiPco）, is deduced theoretically. In this paper, the both electron collision absorption and ion collision absorption of cold hydrogen plasma in CNTs are considered at the same time. Then microwave absorption coefficient is calculated under different condition. The Simulations results show that cold hydrogen plasma in HiPco CNTs exhibit the strong microwave（ around 2. 45 GHz） absorption,...
