Half Life Of Plutonium 240

Artificial nuclides with diminutive number of 94 but with dissimilar mass numbers

Main isotopes of plutonium(₉₄Pu)

Iso­tope Decay abun­dance half-life (t 1/2) mode pro­duct 238Pu trace 87.74 y SF – α 234U 239Pu trace ii.41×xfour y SF – α 235U 240Pu trace 6500 y SF – α 236U 241Pu syn xiv y β− 241Am SF – 242Pu syn 3.73×x5 y SF – α 238U 244Pu trace 8.08×107 y α 240U SF –

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Plutonium (₉₄Pu) is an artificial element, except for trace quantities resulting from neutron capture by uranium, and thus a standard diminutive weight cannot be given. Similar all artificial elements, it has no stable isotopes. It was synthesized long before being found in nature, the first isotope synthesized beingness ²³⁸Pu in 1940. Twenty plutonium radioisotopes have been characterized. The most stable are plutonium-244 with a half-life of lxxx.eight million years, plutonium-242 with a half-life of 373,300 years, and plutonium-239 with a one-half-life of 24,110 years. All of the remaining radioactive isotopes take one-half-lives that are less than 7,000 years. This element too has eight meta states; all have half-lives of less than i 2d.

The isotopes of plutonium range in atomic weight from 228.0387 u (²²⁸Pu) to 247.074 u (²⁴⁷Pu). The primary disuse modes before the most stable isotope, ²⁴⁴Pu, are spontaneous fission and alpha emission; the primary mode after is beta emission. The primary decay products before ²⁴⁴Pu are isotopes of uranium and neptunium (not considering fission products), and the primary disuse products later are isotopes of americium.

List of isotopes [edit]

Nuclide [north i]	Z	North	Isotopic mass (Da) [n 2] [n iii]	Half-life	Decay mode [n 4]	Girl isotope [n 5] [n 6]	Spin and parity [north seven] [northward 8]	Isotopic abundance
	Excitation energy
228Pu	94	134	228.03874(iii)	ane.1(+20−5) s	α (99.9%)	224U	0+
					β+ (.1%)	228Np
229Pu	94	135	229.04015(6)	120(fifty) s	α	225U	3/ii+#
230Pu	94	136	230.039650(xvi)	one.70(17) min	α	226U	0+
					β+ (rare)	230Np
231Pu	94	137	231.041101(28)	eight.6(5) min	β+	231Np	3/ii+#
					α (rare)	227U
232Pu	94	138	232.041187(19)	33.7(5) min	EC (89%)	232Np	0+
					α (11%)	228U
233Pu	94	139	233.04300(5)	xx.9(4) min	β+ (99.88%)	233Np	5/2+#
					α (.12%)	229U
234Pu	94	140	234.043317(7)	8.viii(1) h	EC (94%)	234Np	0+
					α (6%)	230U
235Pu	94	141	235.045286(22)	25.iii(v) min	β+ (99.99%)	235Np	(5/2+)
					α (.0027%)	231U
236Pu	94	142	236.0460580(24)	2.858(viii) y	α	232U	0+
					SF (ane.37×10−7%)	(various)
					CD (2×10−12%)	208Pb 28Mg
					β+β+ (rare)	236U
237Pu	94	143	237.0484097(24)	45.two(1) d	EC	237Np	7/2−
					α (.0042%)	233U
237m1Pu	145.544(x)2 keV			180(20) ms	IT	237Pu	1/ii+
237m2Pu	2900(250) keV			one.ane(1) μs
238Pu	94	144	238.0495599(20)	87.7(1) y	α	234U	0+	Trace[n nine]
					SF (1.9×x−7%)	(various)
					CD (1.4×x−14%)	206Hg 32Si
					CD (six×ten−15%)	180Yb thirtyMg 28Mg
239Pu[n 10] [n eleven]	94	145	239.0521634(20)	2.411(iii)×104 y	α	235U	ane/2+	Trace[n 12]
					SF (3.1×10−x%)	(various)
239m1Pu	391.584(3) keV			193(4) ns			7/ii−
239m2Pu	3100(200) keV			seven.five(10) μs			(5/two+)
240Pu	94	146	240.0538135(20)	6.561(7)×10three y	α	236U	0+	Trace[n thirteen]
					SF (five.7×10−half-dozen%)	(various)
					CD (1.three×x−13%)	206Hg 34Si
241Pu[n 10]	94	147	241.0568515(twenty)	xiv.290(half-dozen) y	β− (99.99%)	241Am	five/ii+
					α (.00245%)	237U
					SF (ii.4×10−fourteen%)	(various)
241m1Pu	161.6(1) keV			0.88(5) μs			ane/ii+
241m2Pu	2200(200) keV			21(3) μs
242Pu	94	148	242.0587426(xx)	3.75(two)×105 y	α	238U	0+
					SF (5.5×10−4%)	(various)
243Pu[n x]	94	149	243.062003(3)	4.956(iii) h	β−	243Am	vii/2+
243mPu	383.half dozen(iv) keV			330(30) ns			(1/2+)
244Pu	94	150	244.064204(5)	viii.00(9)×10seven y	α (99.88%)	240U	0+	Trace[n 14]
					SF (.123%)	(various)
					β−β− (7.3×10−9%)	244Cm
245Pu	94	151	245.067747(15)	x.5(ane) h	β−	245Am	(ix/2−)
246Pu	94	152	246.070205(16)	ten.84(2) d	β−	246mAm	0+
247Pu	94	153	247.07407(32)#	ii.27(23) d	β−	247Am	1/ii+#
This tabular array header & footer: view

1. ^ ^yardPu – Excited nuclear isomer.
2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. ^ # – Atomic mass marked #: value and doubtfulness derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. ^ Modes of decay:
5. ^ Bold italics symbol as daughter – Girl product is nearly stable.
6. ^ Bold symbol as daughter – Daughter product is stable.
7. ^ ( ) spin value – Indicates spin with weak assignment arguments.
8. ^ # – Values marked # are not purely derived from experimental data, simply at least partly from trends of neighboring nuclides (TNN).
9. ^ Double beta decay product of ²³⁸U
10. ^ ^{a b c} fissile nuclide
11. ^ Well-nigh useful isotope for nuclear weapons
12. ^ Neutron capture production of ²³⁸U
13. ^ Intermediate decay product of ²⁴⁴Pu
14. ^ Interstellar, some may also be primordial just such claims are disputed

Actinides vs fission products [edit]

Actinides and fission products by half-life five t e
Actinides[one] by disuse chain				Half-life range (a)	Fission products of 235U past yield[two]
fourn	4n + ane	fourn + ii	4northward + iii		iv.5–vii%	0.04–1.25%	<0.001%
228 Ra№				4–6 a		155 Euþ
244 Cmƒ	241 Puƒ	250 Cf	227 Air-conditioning№	ten–29 a	90 Sr	85 Kr	113m Cdþ
232 Uƒ		238 Puƒ	243 Cmƒ	29–97 a	137 Cs	151 Smþ	121m Sn
248 Bk[3]	249 Cfƒ	242m Amƒ		141–351 a	No fission products take a one-half-life in the range of 100 a–210 ka ...
	241 Amƒ		251 Cfƒ [4]	430–900 a
		226 Ra№	247 Bk	1.3–1.6 ka
240 Pu	229 Th	246 Cmƒ	243 Amƒ	4.7–7.four ka
	245 Cmƒ	250 Cm		8.3–viii.5 ka
			239 Puƒ	24.i ka
		230 Thursday№	231 Pa№	32–76 ka
236 Npƒ	233 Uƒ	234 U№		150–250 ka	99 Tc₡	126 Sn
248 Cm		242 Pu		327–375 ka		79 Se₡
				one.53 Ma	93 Zr
	237 Npƒ			ii.1–6.5 Ma	135 Cs₡	107 Pd
236 U			247 Cmƒ	15–24 Ma		129 I₡
244 Pu				80 Ma	... nor beyond 15.7 Ma[5]
232 Th№		238 U№	235 Uƒ№	0.7–xiv.1 Ga
₡,  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)

Notable isotopes [edit]

• Plutonium-238 has a half-life of 87.74 years^[6] and emits alpha particles. Pure ²³⁸Pu for radioisotope thermoelectric generators that ability some spacecraft is produced by neutron capture on neptunium-237 merely plutonium from spent nuclear fuel tin can contain as much equally a few percent ²³⁸Pu, originating from ²³⁷Np, alpha decay of ²⁴²Cm, or (n,2n) reactions.
• Plutonium-239 is the nigh important isotope of plutonium^{[ citation needed ]}, with a half-life of 24,100 years. ²³⁹Pu and ²⁴¹Pu are fissile, meaning that the nuclei of their atoms can suspension autonomously by being bombarded by tedious moving thermal neutrons, releasing energy, gamma radiations and more neutrons. It can therefore sustain a nuclear concatenation reaction, leading to applications in nuclear weapons and nuclear reactors. ²³⁹Pu is synthesized by irradiating uranium-238 with neutrons in a nuclear reactor, then recovered via nuclear reprocessing of the fuel. Further neutron capture produces successively heavier isotopes.
• Plutonium-240 has a high charge per unit of spontaneous fission, raising the background neutron radiation of plutonium containing it. Plutonium is graded by proportion of ²⁴⁰Pu: weapons grade (< 7%), fuel grade (7–19%) and reactor grade (> xix%). Lower grades are less suited for nuclear weapons and thermal reactors but can fuel fast reactors.
• Plutonium-241 is fissile, only besides beta decays with a half-life of 14 years to americium-241.
• Plutonium-242 is not fissile, not very fertile (requiring three more neutron captures to go fissile), has a low neutron capture cross section, and a longer half-life than any of the lighter isotopes.
• Plutonium-244 is the well-nigh stable isotope of plutonium, with a half-life of about lxxx million years. Information technology is not significantly produced in nuclear reactors because ²⁴³Pu has a short half-life, but some is produced in nuclear explosions. Plutonium-244 has been plant in interstellar infinite^[7] and is has the longest half-life of whatever non-primordial radioisotope.

Production and uses [edit]

Transmutation catamenia between ²³⁸Pu and ²⁴⁴Cm in LWR.^[8]
Transmutation speed not shown and varies profoundly by nuclide.
²⁴⁵Cm–²⁴⁸Cm are long-lived with negligible disuse.

²³⁹Pu, a fissile isotope that is the 2nd most used nuclear fuel in nuclear reactors after uranium-235, and the most used fuel in the fission portion of nuclear weapons, is produced from uranium-238 by neutron capture followed by two beta decays.

²⁴⁰Pu, ²⁴¹Pu, and ²⁴²Pu are produced by further neutron capture. The odd-mass isotopes ²³⁹Pu and ²⁴¹Pu take nigh a 3/4 run a risk of undergoing fission on capture of a thermal neutron and near a 1/4 chance of retaining the neutron and condign the next heavier isotope. The fifty-fifty-mass isotopes are fertile material simply non fissile and also take a lower overall probability (cross department) of neutron capture; therefore, they tend to accumulate in nuclear fuel used in a thermal reactor, the design of nearly all nuclear ability plants today. In plutonium that has been used a 2nd time in thermal reactors in MOX fuel, ²⁴⁰Pu may even be the well-nigh mutual isotope. All plutonium isotopes and other actinides, however, are fissionable with fast neutrons. ²⁴⁰Pu does accept a moderate thermal neutron absorption cross section, so that ²⁴¹Pu production in a thermal reactor becomes a pregnant fraction as large every bit ²³⁹Pu production.

²⁴¹Pu has a half-life of 14 years, and has slightly higher thermal neutron cross sections than ²³⁹Pu for both fission and absorption. While nuclear fuel is beingness used in a reactor, a ²⁴¹Pu nucleus is much more than likely to fission or to capture a neutron than to disuse. ²⁴¹Pu accounts for a significant proportion of fissions in thermal reactor fuel that has been used for some time. However, in spent nuclear fuel that does not rapidly undergo nuclear reprocessing but instead is cooled for years after use, much or most of the ²⁴¹Pu volition beta disuse to americium-241, one of the minor actinides, a strong alpha emitter, and difficult to utilize in thermal reactors.

²⁴²Pu has a particularly low cross section for thermal neutron capture; and it takes 3 neutron absorptions to go another fissile isotope (either curium-245 or ²⁴¹Pu) and fission. Fifty-fifty so, there is a risk either of those 2 fissile isotopes volition neglect to fission but instead absorb a quaternary neutron, becoming curium-246 (on the way to even heavier actinides like californium, which is a neutron emitter by spontaneous fission and difficult to handle) or condign ²⁴²Pu over again; so the mean number of neutrons captivated earlier fission is even higher than iii. Therefore, ²⁴²Pu is peculiarly unsuited to recycling in a thermal reactor and would be better used in a fast reactor where it can exist fissioned direct. All the same, ²⁴²Pu'due south low cantankerous section means that relatively fiddling of it will be transmuted during one cycle in a thermal reactor. ²⁴²Pu's half-life is about xv times as long every bit ²³⁹Pu'southward half-life; therefore, information technology is i/15 as radioactive and not 1 of the larger contributors to nuclear waste radioactivity. ²⁴²Pu's gamma ray emissions are also weaker than those of the other isotopes.^[9]

²⁴³Pu has a one-half-life of only v hours, beta decaying to americium-243. Because ²⁴³Pu has little opportunity to capture an boosted neutron earlier decay, the nuclear fuel cycle does non produce the long-lived ²⁴⁴Pu in pregnant quantity.

²³⁸Pu is not normally produced in as large quantity by the nuclear fuel wheel, only some is produced from neptunium-237 by neutron capture (this reaction tin besides be used with purified neptunium to produce ²³⁸Pu relatively costless of other plutonium isotopes for employ in radioisotope thermoelectric generators), by the (north,2n) reaction of fast neutrons on ²³⁹Pu, or by blastoff decay of curium-242, which is produced by neutron capture from ²⁴¹Am. It has significant thermal neutron cross section for fission, but is more likely to capture a neutron and become ²³⁹Pu.

Industry [edit]

Plutonium-240, -241 and -242 [edit]

The fission cantankerous section for ²³⁹Pu is 747.9 barns for thermal neutrons, while the activation cross section is 270.vii barns (the ratio approximates to 11 fissions for every iv neutron captures). The higher plutonium isotopes are created when the uranium fuel is used for a long time. For high burnup used fuel, the concentrations of the college plutonium isotopes will be college than the depression burnup fuel that is reprocessed to obtain weapons grade plutonium.

The formation of ²⁴⁰Pu, ²⁴¹Pu, and ²⁴²Pu from ²³⁸U

Isotope	Thermal neutron cantankerous section[10] (barns)		Decay Fashion	One-half-life
	Capture	Fission
238U	2.683	0.000	α	4.468 x 109 years
239U	20.57	14.11	β−	23.45 minutes
239Np	77.03	–	β−	2.356 days
239Pu	270.7	747.9	α	24,110 years
240Pu	287.5	0.064	α	six,561 years
241Pu	363.0	1012	β−	14.325 years
242Pu	nineteen.16	0.001	α	373,300 years

Plutonium-239 [edit]

Plutonium-239 is ane of the three fissile materials used for the product of nuclear weapons and in some nuclear reactors as a source of energy. The other fissile materials are uranium-235 and uranium-233. Plutonium-239 is virtually nonexistent in nature. It is made past bombarding uranium-238 with neutrons in a nuclear reactor. Uranium-238 is present in quantity in about reactor fuel; hence plutonium-239 is continuously made in these reactors. Since plutonium-239 can itself be split past neutrons to release free energy, plutonium-239 provides a portion of the energy generation in a nuclear reactor.

A ring of weapons-grade electrorefined plutonium, with 99.96% purity. This 5.3 kg ring is enough plutonium for apply in an efficient nuclear weapon. The band shape is needed to depart from a spherical shape and avoid criticality.

The formation of ²³⁹Pu from ²³⁸U^[11]

Element	Isotope	Thermal neutron capture cantankerous section (barn)	Thermal neutron fission Cross section (barn)	decay fashion	Half-life
U	238	2.68	5·ten−6	α	4.47 x xnine years
U	239	22	15	β−	23 minutes
Np	239	thirty	1	β−	two.36 days
Pu	239	271	750	α	24,110 years

Plutonium-238 [edit]

In that location are small amounts of ²³⁸Pu in the plutonium of usual plutonium-producing reactors. However, isotopic separation would exist quite expensive compared to some other method: when a ²³⁵U atom captures a neutron, it is converted to an excited state of ²³⁶U. Some of the excited ²³⁶U nuclei undergo fission, but some disuse to the ground state of ²³⁶U by emitting gamma radiation. Further neutron capture creates ²³⁷U, which has a half-life of 7 days and thus quickly decays to ²³⁷Np. Since well-nigh all neptunium is produced in this style or consists of isotopes that disuse quickly, i gets nearly pure ²³⁷Np past chemical separation of neptunium. After this chemical separation, ²³⁷Np is over again irradiated by reactor neutrons to be converted to ²³⁸Np, which decays to ²³⁸Pu with a half-life of 2 days.

The formation of ²³⁸Pu from ²³⁵U

Element	Isotope	Thermal neutron cross section	decay mode	Half-life
U	235	99	α	703,800,000 years
U	236	five.3	α	23,420,000 years
U	237	—	β−	6.75 days
Np	237	165 (capture)	α	2,144,000 years
Np	238	—	β−	2.xi days
Pu	238	—	α	87.seven years

²⁴⁰Pu every bit an obstacle to nuclear weapons [edit]

Plutonium-240 undergoes spontaneous fission as a secondary decay mode at a small but pregnant rate. The presence of ²⁴⁰Pu limits the plutonium's use in a nuclear bomb, considering the neutron flux from spontaneous fission initiates the chain reaction prematurely, causing an early release of energy that physically disperses the core before full implosion is reached. This prevents nearly of the cadre from participation in the chain reaction and reduces the flop'south power.

Plutonium consisting of more than well-nigh ninety% ²³⁹Pu is chosen weapons-grade plutonium; plutonium from spent nuclear fuel from commercial power reactors more often than not contains at to the lowest degree 20% ²⁴⁰Pu and is called reactor-grade plutonium. Notwithstanding, modern nuclear weapons apply fusion boosting, which mitigates the predetonation problem; if the pit tin can generate a nuclear weapon yield of fifty-fifty a fraction of a kiloton, which is plenty to start deuterium-tritium fusion, the resulting outburst of neutrons will fission plenty plutonium to ensure a yield of tens of kilotons.

²⁴⁰Pu contamination is the reason plutonium weapons must use the implosion method. Theoretically, pure ²³⁹Pu could be used in a gun-type nuclear weapon, but achieving this level of purity is prohibitively difficult. ²⁴⁰Pu contamination has proven a mixed approving to nuclear weapons pattern. While it created delays and headaches during the Manhattan Project considering of the demand to develop implosion technology, those aforementioned difficulties are currently a barrier to nuclear proliferation. Implosion devices are also inherently more efficient and less prone to accidental detonation than are gun-type weapons.

References [edit]

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: iii–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Diminutive weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael East. (2006). "Diminutive weights of the elements 2005 (IUPAC Technical Report)". Pure and Practical Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
• "News & Notices: Standard Atomic Weights Revised". International Matrimony of Pure and Applied Chemistry. 19 October 2005.
• One-half-life, spin, and isomer data selected from the post-obit sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and disuse properties", Nuclear Physics A, 729: iii–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat ii.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "xi. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN978-0-8493-0485-nine.

1. ^ Plus radium (element 88). While really a sub-actinide, information technology immediately precedes actinium (89) and follows a 3-element gap of instability subsequently polonium (84) where no nuclides take one-half-lives of at to the lowest degree four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium'southward longest lived isotope, at 1,600 years, thus claim the element'south inclusion here.
2. ^ Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor.
3. ^ 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 abiding abundance in 3 samples analysed over a period of almost 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 tin can be set at nigh 10⁴ [years]. No blastoff activeness attributable to the new isomer has been detected; the blastoff half-life is probably greater than 300 [years]."
4. ^ This is the heaviest nuclide with a half-life of at least four years earlier the "sea of instability".
5. ^ Excluding those "classically stable" nuclides with one-half-lives significantly in excess of ²³²Th; e.g., while ^113mCd has a half-life of only fourteen years, that of ¹¹³Cd is nearly eight quadrillion years.
6. ^ Makhijani, Arjun; Seth, Anita (July 1997). "The Employ of Weapons Plutonium every bit Reactor Fuel" (PDF). Energy and Security. Takoma Park, Dr.: Found for Energy and Ecology Research. Retrieved 4 July 2016.
7. ^ Wallner, A.; Faestermann, T.; Feige, J.; Feldstein, C.; Knie, K.; Korschinek, G.; Kutschera, Due west.; Ofan, A.; Paul, Thou.; Quinto, F.; Rugel, G.; Steier, P. (2015). "Abundance of alive 244Pu in deep-sea reservoirs on World points to rarity of actinide nucleosynthesis". Nature Communications. six: 5956. arXiv:1509.08054. Bibcode:2015NatCo...six.5956W. doi:10.1038/ncomms6956. ISSN 2041-1723. PMC4309418. PMID 25601158.
8. ^ Sasahara, Akihiro; Matsumura, Tetsuo; Nicolaou, Giorgos; Papaioannou, Dimitri (April 2004). "Neutron and Gamma Ray Source Evaluation of LWR High Burn-up UO2 and MOX Spent Fuels". Periodical of Nuclear Science and Applied science. 41 (four): 448–456. doi:10.3327/jnst.41.448.
9. ^ "Plutonium Isotopic Results of Known Samples Using the Snap Gamma Spectroscopy Analysis Code and the Robwin Spectrum Fitting Routine" (PDF).
10. ^ National Nuclear Information Middle Interactive Chart of Nuclides Archived 2011-07-21 at the Wayback Machine
11. ^ Miner 1968, p. 541 harvnb mistake: no target: CITEREFMiner1968 (help)

Half Life Of Plutonium 240,

Source: https://en.wikipedia.org/wiki/Isotopes_of_plutonium

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