Das β-Spektrum des Tl204
Theβ-spectrum of Tl204 was measured with Tl204 impregnated NaJ(Tl)crystals. The maximumβ-energy was found to be 761±8 keV. The measured deviations from the statistical shape correspond with the theoretical shape factor for first unique forbidden transitions. Aβ-transition into the 375 keV-level of Pb204 could not be found.