Radioactive rays such as x-rays and gamma rays are all high-energy electromagnetic waves. When the rays pass through different media, they can cause ionization of atoms in the media. This is also called ionizing radiation. The shorter the wavelength of the electromagnetic wave, the stronger its penetration ability. Since the wavelength of the radiation and the size of the atoms are in the same order of magnitude, the molecular absorption coefficient can be obtained by adding the atomic absorption coefficients of each element of the constituent molecules. Therefore, the mass absorption coefficients of the various oxides that make up the glass can be calculated on this principle. The composition of ordinary glass does not effectively absorb such rays, and it is necessary to introduce a large number of elements with high atomic number (such as lead and bismuth) into the glass composition in order to increase its absorption capacity. In addition, since the glass itself easily absorbs strong radiation and becomes dark brown and loses its transparency, it is often required that the glass itself has high radiation resistance.