“…Most of the studies were conducted by irradiating the sample with a radioactive source of 241 Am (energy 59.9 keV) [16, 23-37, 48, 50-52], of 109 Cd (22.69 keV) [30][31][32][33][34][35][36][37][38][39][40][41], and of 137 Cs (32.86 keV) [42]. However, the results obtained for X-ray tube [38,43,45,46], Kelectron capture [43], protons (1 MeV, 2 MeV) [44], synchrotron radiation (10 keV) [47] and high-energy electron beam [53] are also available. The Cu-Kβ/Kα values were obtained by use of Si(Li) [16,24,26,28-33, 35,37-41,43-45,47,48,50], Ge [23,25,27,34,36,42,51,52] and high-resolution double-crystal X-ray spectrometer with a proportional counter Si(220) [46].…”