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Plutonium-241

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Isotope of plutonium

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Plutonium-241
General
Symbol	²⁴¹Pu
Names	plutonium-241
Protons(Z)	94
Neutrons(N)	147
Nuclide data
Natural abundance	0 (synthetic)
Half-life(t_1/2)	14.33 years^[1]
Isotope mass	241.056850^[2]Da
Decay products	²⁴¹Am ²³⁷U
Decay modes
Decay mode	Decay energy (MeV)
β−	0.0208^[3]
α	5.140^[3]
Isotopes of plutonium Complete table of nuclides

Plutonium-241 (²⁴¹
Pu,Pu-241) is anisotope of plutonium formed whenplutonium-240 captures aneutron. Like some other plutonium isotopes (especially²³⁹Pu),²⁴¹Pu isfissile, with aneutron absorption cross section about one-third greater than that of²³⁹Pu, and a similar probability of fissioning on neutron absorption, around 73%. In the non-fission case, neutron capture producesplutonium-242. In general, isotopes with an odd number of neutrons are both more likely to absorb a neutron and more likely to undergo fission on neutron absorption than isotopes with an even number of neutrons.

Decay properties

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Process of successive neutron capture from²³⁹Pu through²⁴⁵Cm, including²⁴¹Pu.

Plutonium-241 is a beta emitter with ahalf-life of 14.33 years, corresponding to a decay of about 5% of²⁴¹Pu nuclei over a one-year period. This decay has aQ-value of only20.8 keV, and does not emitgamma rays.^[3] The longerspent nuclear fuel waits beforereprocessing, the more²⁴¹Pu decays toamericium-241, which is nonfissile (althoughfissionable byfast neutrons) and analpha emitter with ahalf-life of 432.6 years;²⁴¹Am, which does emit gamma rays, is a major contributor to the radioactivity ofnuclear waste on a scale of hundreds to thousands of years.^{[citation needed]} In its fully ionized state, the beta-decay half-life of²⁴¹Pu⁹⁴⁺ decreases to 4.2 days, and onlybound-state beta decay is possible.^[4]

Plutonium-241 also has a rarealpha decay branch touranium-237, occurring in about 0.0025% of decays. Unlike its usual beta decay, this can emit gamma rays, X-rays, and associated electrons.^[1]

Actinides and fission products by half-life v t e
Actinides^[5] bydecay chain				Half-life range (a)	Fission products of²³⁵U byyield^[6]
4n (Thorium)	4n + 1 (Neptunium)	4n + 2 (Radium)	4n + 3 (Actinium)	Half-life range (a)	4.5–7%	0.04–1.25%	<0.001%
²²⁸Ra^№				4–6 a		¹⁵⁵Eu^þ
²⁴⁸Bk^[7]				> 9 a
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
	²⁴⁹Cf^ƒ	^242mAm^ƒ		141–351 a	No fission products have ahalf-life in the range of 100 a–210 ka ...
	²⁴¹Am^ƒ		²⁵¹Cf^ƒ^[8]	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^₡
				1.33 Ma	¹³⁵Cs^₡
	²³⁷Np^ƒ			1.61–6.5 Ma	⁹³Zr	¹⁰⁷Pd
²³⁶U			²⁴⁷Cm^ƒ	15–24 Ma		¹²⁹I^₡
²⁴⁴Pu				80 Ma	... nor beyond 15.7 Ma^[9]
²³²Th^№		²³⁸U^№	²³⁵U^ƒ№	0.7–14.1 Ga	... nor beyond 15.7 Ma^[9]
₡, has thermalneutron capture cross section in the range of 8–50 barns ƒ, fissile №, primarily anaturally occurring radioactive material (NORM) þ, neutron poison (thermal neutron capture cross section greater than 3k barns)

References

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^^a ^bKondev, 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.
^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.
^^a ^b ^cBasunia, M. S. (1 August 2006). "Nuclear Data Sheets for A = 237".Nuclear Data Sheets.107 (8):2323–2422.doi:10.1016/j.nds.2006.07.001.
^Takahashi, K.; Boyd, R. N.; Mathews, G. J.; Yokoi, K. (1 October 1987)."Bound-state beta decay of highly ionized atoms".Physical Review C.36 (4):1522–1528.doi:10.1103/PhysRevC.36.1522.
^Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability afterpolonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap isradon-222 with a half life of less than fourdays). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
^Specifically fromthermal neutron fission of uranium-235, e.g. in a typicalnuclear reactor.
^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]."
^This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".
^Excluding those "classically stable" nuclides with half-lives significantly in excess of²³²Th; e.g., while^113mCd has a half-life of only fourteen years, that of¹¹³Cd is eightquadrillion years.

v t e Mainisotopes of plutonium
²³⁸Pu ²³⁹Pu ²⁴⁰Pu ²⁴¹Pu ²⁴²Pu ²⁴⁴Pu

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