Californium-252

Isotopes of californium (₉₈Cf)
SF<0.01%	–
SF≪0.01%	–
SF0.08%	–
SF3.09%	–
α0.31%	249Cm
α0.31%	250Cm
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Isotopes of californium

Nuclides with atomic number of 98 but with different mass numbers

Californium (₉₈Cf) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was ²⁴⁵Cf in 1950. There are 20 known radioisotopes ranging from ²³⁷Cf to ²⁵⁶Cf and one nuclear isomer, ^249mCf. The longest-lived isotope is ²⁵¹Cf with a half-life of 898 years.

Quick Facts Main isotopes, Decay ...

List of isotopes

More information Nuclide, Z ...

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da)^[3] ^{[n 2]}^{[n 3]}	Half-life^[4]	Decay mode^[4] ^{[n 4]}	Daughter isotope	Spin and parity^[4] ^{[n 5]}^{[n 6]}
Nuclide ^{[n 1]}	Excitation energy			Half-life^[4]	Decay mode^[4] ^{[n 4]}	Daughter isotope	Spin and parity^[4] ^{[n 5]}^{[n 6]}
²³⁷Cf	98	139	237.06220(10)	0.8(2) s	α (70%)	²³³Cm	5/2+#
					SF (30%)	(various)
					β⁺ (rare)	²³⁷Bk
²³⁸Cf	98	140	238.06149(32)#	21.1(13) ms	SF^{[n 7]}	(various)	0+
²³⁸Cf	98	140	238.06149(32)#	21.1(13) ms	α (<5%)	²³⁴Cm	0+
²³⁹Cf^[5]	98	141	239.06248(13)#	28(2) s	α (65%)	²³⁵Cm	(5/2+)
²³⁹Cf^[5]	98	141	239.06248(13)#	28(2) s	β⁺ (35%)	²³⁹Bk	(5/2+)
²⁴⁰Cf	98	142	240.062253(19)	40.3(9) s	α (98.5%)	²³⁶Cm	0+
					SF (1.5%)	(various)
					β⁺?	²⁴⁰Bk
²⁴¹Cf^[5]	98	143	241.06369(18)#	2.35(18) min	β⁺ (85%)	²⁴¹Bk	(7/2−)
²⁴¹Cf^[5]	98	143	241.06369(18)#	2.35(18) min	α (15%)	²³⁷Cm	(7/2−)
²⁴²Cf	98	144	242.063755(14)	3.49(15) min	α (61%)	²³⁸Cm	0+
					β⁺ (39%)	²⁴²Bk
					SF (<0.014%)	(various)
²⁴³Cf	98	145	243.06548(19)#	10.8(3) min	β⁺ (86%)	²⁴³Bk	(1/2+)
²⁴³Cf	98	145	243.06548(19)#	10.8(3) min	α (14%)	²³⁹Cm	(1/2+)
²⁴⁴Cf	98	146	244.0659994(28)	19.5(5) min	α (75%)	²⁴⁰Cm	0+
²⁴⁴Cf	98	146	244.0659994(28)	19.5(5) min	EC (25%)	²⁴⁴Bk	0+
²⁴⁵Cf	98	147	245.0680468(26)	45.0(15) min	β⁺ (64.7%)	²⁴⁵Bk	1/2+
²⁴⁵Cf	98	147	245.0680468(26)	45.0(15) min	α (35.3%)	²⁴¹Cm	1/2+
^245mCf	57(4) keV			>100# ns	IT	²⁴⁵Cf	(7/2+)
²⁴⁶Cf	98	148	246.0688037(16)	35.7(5) h	α	²⁴²Cm	0+
					SF (2.4×10⁻⁴%)	(various)
					EC?	²⁴⁶Bk
²⁴⁷Cf	98	149	247.070971(15)	3.11(3) h	EC (99.965%)	²⁴⁷Bk	(7/2+)
²⁴⁷Cf	98	149	247.070971(15)	3.11(3) h	α (.035%)	²⁴³Cm	(7/2+)
²⁴⁸Cf	98	150	248.0721829(55)	333.5(28) d	α (99.997%)	²⁴⁴Cm	0+
²⁴⁸Cf	98	150	248.0721829(55)	333.5(28) d	SF (.0029%)	(various)	0+
²⁴⁹Cf	98	151	249.0748504(13)	351(2) y	α	²⁴⁵Cm	9/2−
²⁴⁹Cf	98	151	249.0748504(13)	351(2) y	SF (5×10⁻⁷%)	(various)	9/2−
^249mCf	144.98(5) keV			45(5) μs	IT	²⁴⁹Cf	5/2+
²⁵⁰Cf	98	152	250.0764045(17)	13.08(9) y	α (99.923%)	²⁴⁶Cm	0+
²⁵⁰Cf	98	152	250.0764045(17)	13.08(9) y	SF (.077%)	(various)	0+
²⁵¹Cf^{[n 8]}	98	153	251.0795872(42)	898(44) y	α	²⁴⁷Cm	1/2+
^251mCf	370.47(3) keV			1.3(1) μs	IT	²⁵¹Cf	11/2−
²⁵²Cf^{[n 9]}	98	154	252.0816265(25)	2.645(8) y	α (96.8972%)	²⁴⁸Cm	0+
²⁵²Cf^{[n 9]}	98	154	252.0816265(25)	2.645(8) y	SF (3.1028%)^{[n 10]}	(various)	0+
²⁵³Cf	98	155	253.0851337(46)	17.81(8) d	β⁻ (99.69%)	²⁵³Es	(7/2+)
²⁵³Cf	98	155	253.0851337(46)	17.81(8) d	α (.31%)	²⁴⁹Cm	(7/2+)
²⁵⁴Cf	98	156	254.087324(12)	60.5(2) d	SF (99.69%)	(various)	0+
					α (.31%)	²⁵⁰Cm
					β⁻β⁻?	²⁵⁴Fm
²⁵⁵Cf	98	157	255.09105(22)#	85(18) min	β⁻	²⁵⁵Es	(7/2+)
					SF?	(various)
					α?	²⁵¹Cm
²⁵⁶Cf	98	158	256.09344(34)#	12.3(12) min	SF	(various)	0+
					α?	²⁵²Cm
					β⁻β⁻?	²⁵⁶Fm
This table header & footer: view

[n 1]
^mCf – Excited nuclear isomer.
[n 2]
( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
[n 3]
# – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
[n 4]
Modes of decay:

EC: Electron capture

SF: Spontaneous fission
[n 5]
( ) spin value – Indicates spin with weak assignment arguments.
[n 6]
# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
[n 7]
Lightest nuclide known to undergo spontaneous fission as its main decay mode
[n 8]
High neutron cross-section, tends to absorb neutrons
[n 9]
Most common isotope
[N 10]
High neutron emitter, average 3.7 neutrons per fission

References

[1]
CRC 2006, p. 11.196.
[2]
Sonzogni, Alejandro A. (Database Manager), ed. (2008). "Chart of Nuclides". National Nuclear Data Center, Brookhaven National Laboratory. Retrieved 1 March 2010.
[3]
Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
[4]
Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
[5]
Khuyagbaatar, J.; Heßberger, F. P.; Hofmann, S.; Ackermann, D.; Burkhard, H. G.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Maurer, J.; Nishio, K. (12 October 2020). "α decay of Fm 243 143 and Fm 245 145 , and of their daughter nuclei". Physical Review C. 102 (4): 044312. doi:10.1103/PhysRevC.102.044312. ISSN 2469-9985. S2CID 241259726. Retrieved 24 June 2023.
[6]
Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
[7]
Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor.
[8]
Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics. 71 (2): 299. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4.
"The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk²⁴⁸ with a half-life greater than 9 [years]. No growth of Cf²⁴⁸ was detected, and a lower limit for the β⁻ half-life can be set at about 10⁴ [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
[9]
This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".
[10]
Excluding those "classically stable" nuclides with half-lives significantly in excess of ²³²Th; e.g., while ^113mCd has a half-life of only fourteen years, that of ¹¹³Cd is eight quadrillion years.
[11]
Dicello, J. F.; Gross, W.; Kraljevic, U. (1972). "Radiation Quality of Californium-252". Physics in Medicine and Biology. 17 (3): 345–355. Bibcode:1972PMB....17..345D. doi:10.1088/0031-9155/17/3/301. PMID 5070445. S2CID 250786668.
[12]
"Portable Isotopic Neutron Spectroscopy (PINS) for the Military". Frontier Technology Corp. Archived from the original on 2018-06-16. Retrieved 2016-02-24.
[13]
Martin, R. C.; Knauer, J. B.; Balo, P. A. (2000-11-01). "Production, distribution and applications of californium-252 neutron sources". Applied Radiation and Isotopes. 53 (4–5): 785–792. doi:10.1016/s0969-8043(00)00214-1. ISSN 0969-8043. PMID 11003521.
[14]
"Californium-252 & Antimony-Beryllium Sources". Frontier Technology Corp. Retrieved 2016-02-24.
[15]
Maruyama, Y.; van Nagell, J. R.; Yoneda, J.; Donaldson, E.; Hanson, M.; Martin, A.; Wilson, L. C.; Coffey, C. W.; Feola, J. (1984-10-01). "Five-year cure of cervical cancer treated using californium-252 neutron brachytherapy". American Journal of Clinical Oncology. 7 (5): 487–493. doi:10.1097/00000421-198410000-00018. ISSN 0277-3732. PMID 6391143. S2CID 12553815.

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This article uses material from the Wikipedia article Californium-252, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.

[3] [n 1]
^mCf – Excited nuclear isomer.

[5] [n 2]
( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-6] [n 3]
# – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[8] [n 4]
Modes of decay:

EC: Electron capture

SF: Spontaneous fission

[9] [n 5]
( ) spin value – Indicates spin with weak assignment arguments.

[TNN-10] [n 6]
# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[11] [n 7]
Lightest nuclide known to undergo spontaneous fission as its main decay mode

[13] [n 8]
High neutron cross-section, tends to absorb neutrons

[14] [n 9]
Most common isotope

[15] [N 10]
High neutron emitter, average 3.7 neutrons per fission

[FOOTNOTECRC200611.196-1] [1]
CRC 2006, p. 11.196.

[NNDC2008-2] [2]
Sonzogni, Alejandro A. (Database Manager), ed. (2008). "Chart of Nuclides". National Nuclear Data Center, Brookhaven National Laboratory. Retrieved 1 March 2010.

[AME2020_II-4] [3]
Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

[NUBASE2020-7] [4]
Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[239Cf-12] [5]
Khuyagbaatar, J.; Heßberger, F. P.; Hofmann, S.; Ackermann, D.; Burkhard, H. G.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Maurer, J.; Nishio, K. (12 October 2020). "α decay of Fm 243 143 and Fm 245 145 , and of their daughter nuclei". Physical Review C. 102 (4): 044312. doi:10.1103/PhysRevC.102.044312. ISSN 2469-9985. S2CID 241259726. Retrieved 24 June 2023.

[16] [6]
Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.

[17] [7]
Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor.

[18] [8]
Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics. 71 (2): 299. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4.
"The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk²⁴⁸ with a half-life greater than 9 [years]. No growth of Cf²⁴⁸ was detected, and a lower limit for the β⁻ half-life can be set at about 10⁴ [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."

[19] [9]
This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".

[20] [10]
Excluding those "classically stable" nuclides with half-lives significantly in excess of ²³²Th; e.g., while ^113mCd has a half-life of only fourteen years, that of ¹¹³Cd is eight quadrillion years.

[252Cf-Dicello-21] [11]
Dicello, J. F.; Gross, W.; Kraljevic, U. (1972). "Radiation Quality of Californium-252". Physics in Medicine and Biology. 17 (3): 345–355. Bibcode:1972PMB....17..345D. doi:10.1088/0031-9155/17/3/301. PMID 5070445. S2CID 250786668.

[252Cf-frontier-cf252-22] [12]
"Portable Isotopic Neutron Spectroscopy (PINS) for the Military". Frontier Technology Corp. Archived from the original on 2018-06-16. Retrieved 2016-02-24.

[252Cf-Martin-23] [13]
Martin, R. C.; Knauer, J. B.; Balo, P. A. (2000-11-01). "Production, distribution and applications of californium-252 neutron sources". Applied Radiation and Isotopes. 53 (4–5): 785–792. doi:10.1016/s0969-8043(00)00214-1. ISSN 0969-8043. PMID 11003521.

[252Cf-frontier-cf252b-24] [14]
"Californium-252 & Antimony-Beryllium Sources". Frontier Technology Corp. Retrieved 2016-02-24.

[252Cf-Maruyama-25] [15]
Maruyama, Y.; van Nagell, J. R.; Yoneda, J.; Donaldson, E.; Hanson, M.; Martin, A.; Wilson, L. C.; Coffey, C. W.; Feola, J. (1984-10-01). "Five-year cure of cervical cancer treated using californium-252 neutron brachytherapy". American Journal of Clinical Oncology. 7 (5): 487–493. doi:10.1097/00000421-198410000-00018. ISSN 0277-3732. PMID 6391143. S2CID 12553815.

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Actinides and fission products by half-life v t e
Actinides^[6] by decay chain				Half-life range (a)	Fission products of ²³⁵U by yield^[7]
4n	4n + 1	4n + 2	4n + 3	Half-life range (a)	4.5–7%	0.04–1.25%	<0.001%
²²⁸Ra^№				4–6 a		¹⁵⁵Eu^þ
²⁴⁴Cm^ƒ	²⁴¹Pu^ƒ	²⁵⁰Cf	²²⁷Ac^№	10–29 a	⁹⁰Sr	⁸⁵Kr	^113mCd^þ
²³²U^ƒ		²³⁸Pu^ƒ	²⁴³Cm^ƒ	29–97 a	¹³⁷Cs	¹⁵¹Sm^þ	^121mSn
²⁴⁸Bk^[8]	²⁴⁹Cf^ƒ	^242mAm^ƒ		141–351 a	No fission products have a half-life in the range of 100 a–210 ka ...
	²⁴¹Am^ƒ		²⁵¹Cf^ƒ^[9]	430–900 a
		²²⁶Ra^№	²⁴⁷Bk	1.3–1.6 ka
²⁴⁰Pu	²²⁹Th	²⁴⁶Cm^ƒ	²⁴³Am^ƒ	4.7–7.4 ka
	²⁴⁵Cm^ƒ	²⁵⁰Cm		8.3–8.5 ka
			²³⁹Pu^ƒ	24.1 ka
		²³⁰Th^№	²³¹Pa^№	32–76 ka
²³⁶Np^ƒ	²³³U^ƒ	²³⁴U^№		150–250 ka	⁹⁹Tc^₡	¹²⁶Sn
²⁴⁸Cm		²⁴²Pu		327–375 ka		⁷⁹Se^₡
				1.53 Ma	⁹³Zr
	²³⁷Np^ƒ			2.1–6.5 Ma	¹³⁵Cs^₡	¹⁰⁷Pd
²³⁶U			²⁴⁷Cm^ƒ	15–24 Ma		¹²⁹I^₡
²⁴⁴Pu				80 Ma	... nor beyond 15.7 Ma^[10]
²³²Th^№		²³⁸U^№	²³⁵U^ƒ№	0.7–14.1 Ga	... nor beyond 15.7 Ma^[10]
₡, has thermal neutron capture cross section in the range of 8–50 barns ƒ, fissile №, primarily a naturally occurring radioactive material (NORM) þ, neutron poison (thermal neutron capture cross section greater than 3k barns)

Californium-252

Isotopes of californium

List of isotopes

Actinides vs fission products

Californium-252

Nuclear reactors

Military and defense

Oil and petroleum

Medicine

References

Sources

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