Table 1.

Decay data for ²²³Ra, ²²⁵Ac and ²²⁷Th and their daughters. The bolded energies are within the ideal energy range of the gamma camera

Isotope	Half-life (days)	Daughters				Principal emitted photon energies (keV) (% abundance)
223Ra	11.43					11.7 (25.0), 81.1 (15.0), 83.8 (24.9), 94.9 (11.3), 144.2 (3.2), 154.2 (5.6), 269.5 (13.7) and 323.9 (3.9)
		219Rn				271.2 (10.8) and 401.8 (6.4)
			211Pb			404.9 (3.8) and 832.0 (3.5)
				211Bi		351.1 (12.9)
225Ac	10					12.0 (6.9) and 14.8 (6.7)
		221Fr				218.2 (11.6)
				213Bi		440.5 (26.1)
227Th	18.68					12.3 (21.0), 50.1 (8.0), 236.0 (12.3) and 256.3 (7.0)
		223Ra				11.7 (25.0), 81.1 (15.0), 83.8 (24.9), 94.9 (11.3), 144.2 (3.2), 154.2 (5.6), 269.5 (13.7) and 323.9 (3.9)
			219Rn			271.2 (10.8) and 401.8 (6.4)
				211Pb		404.9 (3.8) and 832.0 (3.5)
					211Bi	351.1 (12.9)