WikiProject Elements / Isotopes  (Rated List-class, Low-importance)
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This article is part of Wikipedia:Wikiproject Isotopes. Please keep style and phrasings consistent across the set of pages. For later reference and improved reliability, data from all considered multiple sources is collected here. References are denoted by these letters:

  • (A) G. Audi, O. Bersillon, J. Blachot, A.H. Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003). — Where this source indicates a speculative value, the # mark is also applied to values with weak assignment arguments from other sources, if grouped together. An asterisk after the A means that a comment of some importance may be available in the original.
  • (B) National Nuclear Data Center, Brookhaven National Laboratory, information extracted from the NuDat 2.1 database. (Retrieved Sept. 2005, from the code of the popup boxes).
  • (C) David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes. — The CRC uses rounded numbers with implied uncertainties, where this concurs with the range of another source it is treated as exactly equal in this comparison.
  • (D) More specific level data from reference B's Levels and Gammas database.
  • (E) Same as B but excitation energy replaced with that from D.
  Z   N refs symbol   half-life                   spin              excitation energy
 62  66 AB  |Sm-128  |0.5# s                     |0+
 62  67 A   |Sm-129  |550(100) ms                |5/2+#
 62  67 B   |Sm-129  |0.55(10) s                 |(1/2+)
 62  67 C   |Sm-129  |~0.55 s                    |
 62  68 AB  |Sm-130  |1# s                       |0+
 62  69 A   |Sm-131  |1.2(2) s                   |5/2+#
 62  69 BC  |Sm-131  |1.2(2) s                   |
 62  70 AB  |Sm-132  |4.0(3) s                   |0+
 62  70 C   |Sm-132  |4.0 s                      |
 62  71 A   |Sm-133  |2.90(17) s                 |(5/2+)
 62  71 B   |Sm-133  |3.7(7) s                   |(5/2+)
 62  71 C   |Sm-133  |2.9 s                      |5/2+
 62  72 A   |Sm-134  |10(1) s                    |0+
 62  72 B   |Sm-134  |9.5(8) s                   |0+
 62  72 C   |Sm-134  |11. s                      |0+
 62  73 A   |Sm-135  |10.3(5) s                  |(7/2+)
 62  73 B   |Sm-135  |10.3(5) s                  |(3/2+,5/2+)
 62  73 C   |Sm-135  |10. s                      |7/2+
 62  73 A*  |Sm-135m |2.4(9) s                   |(3/2+,5/2+)      |0(300)# keV
 62  74 AB  |Sm-136  |47(2) s                    |0+
 62  74 C   |Sm-136  |42. s                      |0+
 62  74 AD  |Sm-136m |15(1) µs                   |(8-)             |2264.7(11) keV
 62  75 AB  |Sm-137  |45(1) s                    |(9/2-)
 62  75 C   |Sm-137  |45. s                      |
 62  75 A   |Sm-137m |20# s                      |1/2+#            |180(50)# keV
 62  76 AB  |Sm-138  |3.1(2) min                 |0+
 62  76 C   |Sm-138  |3.0 min                    |0+
 62  77 AB  |Sm-139  |2.57(10) min               |1/2+
 62  77 C   |Sm-139  |2.6 min                    |1/2+
 62  77 AE  |Sm-139m |10.7(6) s                  |11/2-            |457.40(22) keV
 62  77 C   |Sm-139m |10. s                      |(11/2-)
 62  78 ABC |Sm-140  |14.82(12) min              |0+
 62  79 ABC |Sm-141  |10.2(2) min                |1/2+
 62  79 AE  |Sm-141m |22.6(2) min                |11/2-            |176.0(3) keV
 62  79 C   |Sm-141m |22.6 min                   |11/2-
 62  80 ABC |Sm-142  |72.49(5) min               |0+
 62  81 AB  |Sm-143  |8.75(8) min                |3/2+
 62  81 C   |Sm-143  |8.83 min                   |3/2+
 62  81 AE  |Sm-143m1|66(2) s                    |11/2-            |753.99(16) keV
 62  81 C   |Sm-143m1|1.10 min                   |11/2-
 62  81 AD  |Sm-143m2|30(3) ms                   |23/2(-)          |2793.8(13) keV
 62  82 ABC |Sm-144  |STABLE                     |0+
 62  82 AD  |Sm-144m |880(25) ns                 |6+               |2323.60(8) keV
 62  83 ABC |Sm-145  |340(3) d                   |7/2-
 62  83 A   |Sm-145m |990(170) ns                |(49/2+)          |8786.2(7) keV
 62  83 D   |Sm-145m |0.96(+19-15) µs            |(49/2+)          |8786.2(7) keV
 62  84 ABC |Sm-146  |1.03(5)E+8 a               |0+
 62  85 A   |Sm-147  |106.0(11)E+12              |7/2-
 62  85 BC  |Sm-147  |1.06(2)E+11 a              |7/2-
 62  86 ABC |Sm-148  |7(3)E+15 a                 |0+
 62  87 A   |Sm-149  |STABLE [>2E+15 a]          |7/2-
 62  87 B   |Sm-149  |STABLE                     |7/2-
 62  87 C   |Sm-149  |1E+16 a                    |7/2-
 62  88 ABC |Sm-150  |STABLE                     |0+
 62  89 AB  |Sm-151  |90(8) a                    |5/2-
 62  89 C   |Sm-151  |90. a                      |5/2-
 62  89 AD  |Sm-151m |1.4(1) µs                  |(11/2)-          |261.13(4) keV
 62  90 ABC |Sm-152  |STABLE                     |0+
 62  91 ABC |Sm-153  |46.284(4) h                |3/2+
 62  91 AD  |Sm-153m |10.6(3) ms                 |11/2-            |98.37(10) keV
 62  92 A   |Sm-154  |STABLE [>2.3E+18 a]        |0+
 62  92 BC  |Sm-154  |STABLE                     |0+
 62  93 AB  |Sm-155  |22.3(2) min                |3/2-
 62  93 C   |Sm-155  |22.2 min                   |3/2-
 62  94 ABC |Sm-156  |9.4(2) h                   |0+
 62  94 AD  |Sm-156m |185(7) ns                  |5-               |1397.55(9) keV
 62  95 AB  |Sm-157  |8.03(7) min                |(3/2-)
 62  95 C   |Sm-157  |8.0 min                    |3/2-
 62  96 AB  |Sm-158  |5.30(3) min                |0+
 62  96 C   |Sm-158  |5.5 min                    |0+
 62  97 AB  |Sm-159  |11.37(15) s                |5/2-
 62  97 C   |Sm-159  |11.3 s                     |
 62  98 ABC |Sm-160  |9.6(3) s                   |0+
 62  99 A   |Sm-161  |4.8(8) s                   |7/2+#
 62  99 B   |Sm-161  |4.8(8) s                   |
 62  99 C   |Sm-161  |~4.8 s                     |
 62 100 A   |Sm-162  |2.4(5) s                   |0+
 62 100 B   |Sm-162  |~2 s                       |0+
 62 101 A   |Sm-163  |1# s                       |1/2-#
 62 101 B   |Sm-163  |~1 s                       |
 62 102 A   |Sm-164  |500# ms                    |0+
 62 102 B   |Sm-164  |~0.5 s                     |0+
 62 103 A   |Sm-165  |200# ms                    |5/2-#
 62 103 B   |Sm-165  |~0.2 s                     |

Femto 12:32, 15 November 2005 (UTC)

Contents

TalkEdit


Note that 4 of the reported 5 of the reported stable isotopes of 62Sm are EE's and that the isotope EO62Sm149 destabilizes in the direction of becoming EO60Nd145. The isotope EE62Sm146 is then reported to be an alpha emitter and becoming EE60Nd142. The isotopes EO62Sm147 and EE62Sm148 are also reported as alpha emitters, and changing to EO60Nd143 and EE60Nd144 which are both reported stable. The question is if the EO isotopes 62Sm147 and 149 are all stable or very long lived and if EO62Sm145 changes in the direction of having 2 more neutrons, then why would 2 more balanced neutrons added to a stable EE62Sm144 turn it into a short lived alpha emitter? This is a unique situation where after an element achieves a condition of stability on the low AMU side, it then becomes unstable when 2 more neutrons are added. Could they have been added on in the wrong (unbalanced) position? That is the trouble with alpha emitters. They obscure the underlying accumulation process.WFPM (talk) 12:40, 28 September 2011 (UTC)

In answer to your request on my talk page for comment, I find it difficult to follow this argument so I will start by asking some questions about it:

1) From the Handbook of chemical physics, the isotope Sm-145 captures 2 electrons to form first Pm-145 and then Nd-145, not Nd-144 as you have said. But Nd-145 is EO, not EE. Are corrections needed here?

2) Why do you describe 62Sm147 and 149 as EE? I thought EE meant even numbers of both protons and neutrons. Should this be EO? Or does the EE-EO notation perhaps mean something else??

3) What are "balanced" and "unbalanced" neutrons please? And what do you mean by the wrong (unbalanced) position. I learned that nuclei are quantum systems in which the nucleons do not have fixed positions but rather orbitals or wavefunctions.

4) "...alpha emitters ... obscure the underlying accumulation process. Here I do not understand what accumulation is meant or why it is obscured. Dirac66 (talk) 00:44, 23 July 2009 (UTC)

This is a unique situation where on the low "extra neutron" end of the additional neutron section of the lanthanides The element first has a stable isotope, namely EE62Sm144 and then becomes an alpha emitter if you add additional neutrons. Notice that the alpha emission characteristic goes away when you add additional neutrons, and in the rest of the lanthanide series the addition of 2 more neutrons from the low end leads to a more common stable isotope. As to balanced positions I refer to the structural concept of my models where the the addition of two additional neutrons on opposite sides of the axis of rotation will rebalance the assymetry caused by the addition of a single neutron. Finally, it is evident that the occurrence of alpha emission is a phenomenon not related to the overall properties of the nucleus, but rather the occurrence of a localized defect, whereby an alpha particle structured number of nucleons are able to acquire a sufficient amount of activating energy such as to be able to come loose from the rest of the structure and is thus not a process involving the entire nuclear structure and thus acts as a sort of random interference with the nuclear accumulation process.WFPM (talk) 02:01, 23 July 2009 (UTC)

Fission yield values depend on parent isotope, correct?Edit

In a number of places of this article, a specific isotope's "yield" is cited as a percentage, with no further information. Isn't the yield based on the parent element/isotope? If so, the parent should be specified clearly. If the parent is the same for every isotope of samarium (seems unlikely) it could be specified in one of the leader paragraphs. -- Dan Griscom (talk) 11:45, 1 May 2011 (UTC)

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Samarium-151Edit

Since nuclear fuel is used for several years (burnup) in a nuclear power plant, the final amount of 151Sm in the spent nuclear fuel at discharge is only a small fraction of the total 151Sm produced during the use of the fuel.

This does not make any sense to me, and I strongly suspect it's wrong. With nearly 100 years half life only a few percent of 151Sm decays in the few years it sits in the reactor, so almost all should be present at discharge. --Feldkurat Katz (talk) 17:18, 16 May 2017 (UTC)

You are correct that most of the Sm-151 does not decay during that time. However, this is not the primary means of depletion. While the Sm-151 remains inside the reactor, it is exposed to neutron radiation from the ongoing fission; as described in the previous paragraph to the sentence you quoted, Sm-151 absorbs neutrons and is transmuted into stable Sm-152. Thus, its concentration in spent fuel is lower than one would naïvely expect. Magic9mushroom (talk) 09:05, 6 August 2017 (UTC)

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