A simple model to describe the microwave absorption of magnetized hydrogen plasma embedded inside the carbon nanotubes (CNTs), which were grown by iron-catalyzed high-pressure disproportionation (HiPco), is proposed and analyzed. By using Maxwell equations in conjunction with a general expression of the complex permittivity of magnetized hydrogen plasma in HiPco CNTs, known as the Appleton–Hartree formula, the absorption coefficients of the system for right-hand circularly wave propagation along and across the static magnetic field are obtained. The effects of the continuously changing the electron density, the collision frequency, and the cyclotron frequency on the absorption of the microwave are discussed.
