Determination of probabilities of vacancy transfer from K to L shell using K X-ray intensity ratios

K to L shell vacancy transfer probabilities (ηKL) for 26 elements in the atomic region 23 ≤ Z ≤ 57 were determined by measuring the IKβ/IKα intensity ratios. The targets were irradiated with photons at 59.543 keV from Am241 annular source. The K X-rays from different targets were detected with a high resolution Si(Li) detector. Theoretical values were calculated using the radiative and radiationless transition rates of these elements. The measured values of ηKL are compared with the theoretical values and data of others. The measurement vacancy transfer probabilities are least-square fitted to third-order polynomials to obtain analytical relations that represent these probabilities as a function of atomic number. The measured values of ηKL for V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se and Br (respectively 1.544, 1.509, 1.467, 1.453, 1.415, 1.394, 1.361, 1.330, 1.238, 1.204 and 1.200) are being reported here for the first time, the overall error in the present measurements is estimated to be less than 8 per cent