Identified radionuclide

Gamma-ray energy (KeV)

Gamma emission probability

Source of gamma ray transition

Th-234

92.58

0.0558 ± 0.0030

U-238 series-doublet peak

Ac-228

129.06

0.0242 ± 0.0009

Th-232 series

Ac-228

153.97

0.0072 ± 0.0002

Th-232 series

U-235

185.72

0.572 ± 0.0005

Primordial U-235

Ra-226

186.21

0.0359 ± 0.0019

U-238 series

Ac-228

209.25

0.0389 ± 0.0007

Th-232 series

Pb-212

238.63

0.4360 ± 0.0030

Th-232 series

Pb-214

241.99

0.0725 ± 0.0002

Th-238 series

Ac-228

270.24

0.0346 ± 0.0006

Th-232 series

Tl-208

277.35

0.0227 ± 0.0003

Th-232 series

Pb-214

295.22

0.1842 ± 0.0004

Th-238 series

Pb-214

300.08

0.0318 ± 0.0013

Th-232 series

Ac-228

328

0.0295 ± 0.0012

Th-232 series

Ac-229

338.32

0.1127 ± 0.0019

Th-232 series

Pb-214

351.93

0.3560 ± 0.0007

Th-238 series

Ac-228

463

0.0440 ± 0.0007

Th-232 series

Annihilation

511

Annihilation radiation

Tl-208

583.19

0.3055 ± 0.0017

Th-232 series

Bi-214

609.31

0.4549 ± 0.0016

U-238 series

Cs-137

661.65

0.8510 ± 0.0020

Man-made

Bi-212

727.33

0.0674 ± 0.0012

Th-232 series

Bi-214

768.35

0.0489 ± 0.0001

U-238 series

Ac-228

794.94

0.0425 ± 0.0007

Th-232 series

Tl-208

860.56

0.0448 ± 0.0004

Th-232 series

Ac-228

911.2

0.2580 ± 0.0040

Th-232 series

Bi-214

934.06

0.0311 ± 0.0001

U-238 series

Ac-228

964.76

0.0499 ± 0.0002

Th-232 series

Ac-228

968.97

0.1580 ± 0.0030

Th-232 series

Bi-214

1120.28

0.1492 ± 0.0003

U-238 series

Bi-214

1238.11

0.0583 ± 0.0015

U-238 series

Bi-214

1377.67

0.0399 ± 0.0001

U-238 series

Bi-214

1407.98

0.0239 ± 0.001

U-238 series

K-40

1460.83

0.1066 ± 0.0013

Primordial K-40

Ac-228

1588.19

0.0322 ± 0.0008

Th-232 series

Bi-212

1620.5

0.0151 ± 0.0003

Th-232 series

Bi-214

1729.59

0.0298 ± 0.0001

U-238 series

Bi-214

1764.49

0.1530 ± 0.0003

U-238 series

Bi-214

2204.21

0.0492 ± 0.0002

U-238 series

Tl-208

2614.5

0.3585 ± 0.0007

Th-232 series