SINGLE DETECTOR METHOD FOR HIGH RESOLUTION INTERNAL CONVERSION COEFFICIENT MEASUREMENTS

A method for measuring internal conversion coefficients, in which γ rays and conversion electrons are detected in the same Si(Li) detector, was developed. The energy spread for both γ rays and electrons is 5 to 7 keV. The detector is mounted on a cold finger in a vacuum chamber with the source. The chamber has an externally controlled aluminum electron absorber between source and detector for γ-ray measurements, which can be rotated away for electron measurements. This apparatus was calibrated using nine well known conversion coefficients with electron energies from 62 to 973 keV. The αK of the 355 keV transition of 133Cs and the αK and αL of the 482 transition of 181Ta were measured by this method. The values are (0.020±0.001), (0.0234±0.0010), and (0.0054±0.0003), respectively. © 1969 The American Institute of Physics.