同位素符号

半衰期(a)

比活度(Bq/g)

α粒子能量，Mev

(强度，%)

β粒子能量，Mev

(强度，%)

γ能量，Mev

(强度，%)

²³⁸U

4.468 × 109

1.24 × 10⁴

4.196 (77)

4.149 (23)

0.04955 (0.32)

²³⁴Th

24.1d

8.58 × 10¹⁴

0.1985 (72.5)

0.104 (20.7)

0.06286, 0.06329

0.09328, 0.09280

0.11281 (0.24)

^234mPa

1.17min

2.54 × 10¹⁹

2.29 (98)

0.7666 (0.207)

1.001025 (0.59)

²³⁴U

2.45 × 105

2.31 × 10⁸

4.776 (72.5)

4.723 (27.5)

0.0532 (0.119)

0.1209 (0.041)