Emission probability measurement of γ- and X- rays in Ra-226 and Pb-210 decay.

The emission intensities of 186.21keV, 46.54keV, XL(Bi) and XK(Rn) photons were measured with calibrated HPGe detectors. The efficiency was computed with the MCNP Monte Carlo code and validated using experimental points. Sources of Ra-226 were prepared from two different radioactive materials. The X-ray emission intensities in Ra-226 decay were determined without X-rays from the daughter decay products using a radon emanation source. The standard CMI source with Pb-210 was used and compared with a source prepared from the NPL solution delivered under the EMRP project "Metrology for processing materials with high natural radioactivity - MetroNORM".