The photoionization,i.e.,the emission of an electron after the absorption of a photon,is one of the most fundamental atomic processes in light-matter interaction which have been studied for many years.The investigations of photoionization are therefore important in a wide range of conventional and modem applications in science and industry.For example,reliable data of photoionization are required for astrophysical interpretations and modeling of laboratory plasmas or hotgas [1,2].