Contents

Selected Radioactive Isotopes

Appendix B Selected Radioactive Isotopes

Decay modes are $α α size 12{α} {}$ , $β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$ , $β^{+} β^{+} size 12{β rSup { size 8{+{}} } } {}$ , electron capture (EC) and isomeric transition (IT). EC results in the same daughter nucleus as would $β^{+} β^{+} size 12{β rSup { size 8{+{}} } } {}$ decay. IT is a transition from a metastable excited state. Energies for $β^{\pm} β^{\pm} size 12{β rSup { size 8{ +- {}} } } {}$ decays are the maxima; average energies are roughly one-half the maxima.

Isotope	t _1/2	DecayMode(s)	Energy(MeV)	Percent		$γ γ size 12{γ} {}$ -Ray Energy(MeV)	Percent
$3 H 3 H size 12{rSup { size 8{ 3 {}} }H} {}$	12.33 y	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.0186	100%
$14 C 14 C size 12{rSup { size 8{ 6 {}} }Li} {}$	5730 y	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.156	100%
$13 N 13 N size 12{rSup { size 8{ 13 {}} }N} {}$	9.96 min	$β^{+} β^{+} size 12{β rSup { size 8{+{}} } } {}$	1.20	100%
$22 Na 22 Na size 12{rSup { size 8{ 6 {}} }Li} {}$	2.602 y	$β^{+} β^{+} size 12{β rSup { size 8{+{}} } } {}$	0.55	90%	$γ γ size 12{γ} {}$	1.27	100%
$32 P 32 P size 12{rSup { size 8{ 32 {}} }P} {}$	14.28 d	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	1.71	100%
$35 S 35 S size 12{rSup { size 8{ 35 {}} }S} {}$	87.4 d	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.167	100%
$36 Cl 36 Cl size 12{rSup { size 8{ 36 {}} }Cl} {}$	$3 . 00 \times 10^{5} y 3 . 00 \times 10^{5} y size 12{3 "." "00" times "10" rSup { size 8{5} } y} {}$	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.710	100%
$40 K 40 K size 12{rSup { size 8{ 40 {}} }K} {}$	$1 . 28 \times 10^{9} y 1 . 28 \times 10^{9} y size 12{1 "." "28" times "10" rSup { size 8{9} } y} {}$	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	1.31	89%
$43 K 43 K size 12{rSup { size 8{ 43 {}} }K} {}$	22.3 h	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.827	87%	$γ s γ$	0.373	87%
						0.618	87%
$45 Ca 45 Ca size 12{rSup { size 8{ 6 {}} }Li} {}$	165 d	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.257	100%
$51 Cr 51 Cr size 12{rSup { size 8{ 51 {}} }Cr} {}$	27.70 d	EC			$γ γ size 12{γ} {}$	0.320	10%
$52 Mn 52 Mn size 12{rSup { size 8{ 52 {}} }Mn} {}$	5.59d	$β^{+} β^{+} size 12{β rSup { size 8{+{}} } } {}$	3.69	28%	$γ s γ$	1.33	28%
						1.43	28%
$52 Fe 52 Fe size 12{rSup { size 8{ 52 {}} }Fe} {}$	8.27 h	$β^{+} β^{+} size 12{β rSup { size 8{+{}} } } {}$	1.80	43%		0.169	43%
						0.378	43%
$59 Fe 59 Fe size 12{rSup { size 8{ 59 {}} }Fe} {}$	44.6 d	$β^{-} s β^{-} s size 12{β rSup { size 8{ - {}} } s} {}$	0.273	45%	$γ s γ$	1.10	57%
			0.466	55%		1.29	43%
$60 Co 60 Co size 12{rSup { size 8{ 60 {}} }Co} {}$	5.271 y	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.318	100%	$γ s γ$	1.17	100%
						1.33	100%
$65 Zn 65 Zn size 12{rSup { size 8{ 65 {}} }Zn} {}$	244.1 d	EC			$γ γ size 12{γ} {}$	1.12	51%
$67 Ga 67 Ga size 12{rSup { size 8{ 67 {}} }Ga} {}$	78.3 h	EC			$γ s γ$	0.0933	70%
						0.185	35%
						0.300	19%
						others
$75 Se 75 Se size 12{rSup { size 8{ 75 {}} }Se} {}$	118.5 d	EC			$γ s γ$	0.121	20%
						0.136	65%
						0.265	68%
						0.280	20%
						others
$86 Rb 86 Rb size 12{rSup { size 8{ 86 {}} }Rb} {}$	18.8 d	$β^{-} s β^{-} s size 12{β rSup { size 8{ - {}} } s} {}$	0.69	9%	$γ γ size 12{γ} {}$	1.08	9%
			1.77	91%
$85 Sr 85 Sr size 12{rSup { size 8{ 85 {}} }Sr} {}$	64.8 d	EC			$γ γ size 12{γ} {}$	0.514	100%
$90 Sr 90 Sr size 12{rSup { size 8{ 90 {}} }Sr} {}$	28.8 y	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	0.546	100%
$90 Y 90 Y size 12{rSup { size 8{ 90 {}} }Y} {}$	64.1 h	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	2.28	100%
$99m Tc 99m Tc size 12{rSup { size 8{ 99m {}} }Tc} {}$	6.02 h	IT			$γ γ size 12{γ} {}$	0.142	100%
$113m In 113m In size 12{rSup { size 8{ 113m {}} }In} {}$	99.5 min	IT			$γ γ size 12{γ} {}$	0.392	100%
$123 I 123 I size 12{rSup { size 8{ 123 {}} }I} {}$	13.0 h	EC			$γ γ size 12{γ} {}$	0.159	$≈100% ≈100% size 12{ approx "100"%} {}$
$131 I 131 I size 12{rSup { size 8{ 131 {}} }I} {}$	8.040 d	$β^{-} s β^{-} s size 12{β rSup { size 8{ - {}} } s} {}$	0.248	7%	$γ s γ$	0.364	85%
			0.607	93%		others
			others
$129 Cs 129 Cs size 12{rSup { size 8{ 129 {}} }Cs} {}$	32.3 h	EC			$γ s γ$	0.0400	35%
						0.372	32%
						0.411	25%
						others
$137 Cs 137 Cs size 12{rSup { size 8{ 137 {}} }Cs} {}$	30.17 y	$β^{-} s β^{-} s size 12{β rSup { size 8{ - {}} } s} {}$	0.511	95%	$γ γ size 12{γ} {}$	0.662	95%
			1.17	5%
$140 Ba 140 Ba size 12{rSup { size 8{ 140 {}} }Ba} {}$	12.79 d	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	1.035	$≈100% ≈100% size 12{ approx "100"%} {}$	$γ s γ$	0.030	25%
						0.044	65%
						0.537	24%
						others
$198 Au 198 Au size 12{rSup { size 8{ 198 {}} }Au} {}$	2.696 d	$β^{-} β^{-} size 12{β rSup { size 8{ - {}} } } {}$	1.161	$≈100% ≈100% size 12{ approx "100"%} {}$	$γ γ size 12{γ} {}$	0.412	$≈100% ≈100% size 12{ approx "100"%} {}$
$197 Hg 197 Hg size 12{rSup { size 8{ 197 {}} }Hg} {}$	64.1 h	EC			$γ γ size 12{γ} {}$	0.0733	100%
$210 Po 210 Po size 12{rSup { size 8{ 210 {}} }Po} {}$	138.38 d	$α α size 12{α} {}$	5.41	100%
$226 Ra 226 Ra size 12{rSup { size 8{ 226 {}} }Ra} {}$	$1 . 60 \times 10^{3} y 1 . 60 \times 10^{3} y size 12{1 "." "60" times "10" rSup { size 8{3} } y} {}$	$α s α s size 12{αs} {}$	4.68	5%	$γ γ size 12{γ} {}$	0.186	100%
			4.87	95%
$235 U 235 U size 12{rSup { size 8{ 6 {}} }Li} {}$	$7 . 038 \times 10^{8} y 7 . 038 \times 10^{8} y size 12{7 "." "038" times "10" rSup { size 8{8} } y} {}$	$α α size 12{α} {}$	4.68	$≈100% ≈100% size 12{ approx "100"%} {}$	$γ s γ$	numerous	<0.400%
$238 U 238 U size 12{rSup { size 8{ 6 {}} }Li} {}$	$4 . 468 \times 10^{9} y 4 . 468 \times 10^{9} y size 12{4 "." "468" times "10" rSup { size 8{9} } y} {}$	$α s α s size 12{αs} {}$	4.22	23%	$γ γ size 12{γ} {}$	0.050	23%
			4.27	77%
$237 Np 237 Np size 12{rSup { size 8{ 237 {}} }Np} {}$	$2 . 14 \times 10^{6} y 2 . 14 \times 10^{6} y size 12{2 "." "14" times "10" rSup { size 8{6} } y} {}$	$α s α s size 12{αs} {}$	numerous		$γ s γ$	numerous	<0.250%
			4.96 (max.)
$239 Pu 239 Pu size 12{rSup { size 8{ 239 {}} }Pu} {}$	$2 . 41 \times 10^{4} y 2 . 41 \times 10^{4} y size 12{2 "." "41" times "10" rSup { size 8{4} } y} {}$	$α s α s size 12{αs} {}$	5.19	11%	$γ s γ$	$7 . 5 \times 10^{- 5} 7 . 5 \times 10^{- 5} size 12{7 "." 5 times "10" rSup { size 8{ - 5} } } {}$	73%
			5.23	15%		0.013	15%
			5.24	73%		0.052	10%
						others
$243 Am 243 Am size 12{rSup { size 8{ 243 {}} }Am} {}$	$7 . 37 \times 10^{3} y 7 . 37 \times 10^{3} y size 12{7 "." "37" times "10" rSup { size 8{3} } y} {}$	$α s α s size 12{αs} {}$	Max. 5.44		$γ s γ$	0.075
			5.37	88%		others
			5.32	11%
			others

Table B1 Selected Radioactive Isotopes