X-RAY SPECTROSCOPY RELATED TO DETERMINATION OF ELECTRON-CAPTURE RATIOS

The methods employed for measuring LM K capture ratios were anallyzed and the corresponding data were compiled in different tables. An alternative method is introduced here using very thin NaI(Tl) crystals to detect X-rays, in conjunction with Ge(Li) counters for gamma-rays. A triple coincideence arrangement was used. Calibration in energy and absorption corrections were made. The particular trasitions of 133Ba to 133Cs (437 keV level), 57Co to 57Fe (136 keV level), and 57Co to 57Fe (706 keV level) were studied. The values of the LM K ratios obtained were 1.15±0.08, 0.15±0.02 and 0.088±0.040, respectively. When possible, Q-values were derived from the data obtained and compared with mass-table predictions. © 1969.