Isotopes of thulium explained

Naturally occurring thulium (69Tm) is composed of one stable isotope, 169Tm (100% natural abundance). Thirty-nine radioisotopes have been characterized, with the most stable being 171Tm with a half-life of 1.92 years, 170Tm with a half-life of 128.6 days, 168Tm with a half-life of 93.1 days, and 167Tm with a half-life of 9.25 days. All of the remaining radioactive isotopes have half-lives that are less than 64 hours, and the majority of these have half-lives that are less than 2 minutes. This element also has 26 meta states, with the most stable being 164mTm (t1/2 5.1 minutes), 160mTm (t1/2 74.5 seconds) and 155mTm (t1/2 45 seconds).

The known isotopes of thulium range from 144Tm to 183Tm. The primary decay mode before the most abundant stable isotope, 169Tm, is electron capture, and the primary mode after is beta emission. The primary decay products before 169Tm are erbium isotopes, and the primary products after are ytterbium isotopes. All isotopes of thulium are either radioactive or, in the case of 169Tm, observationally stable, meaning that 169Tm is predicted to be radioactive but no actual decay has been observed.

List of isotopes

|-id=Thulium-144| 144Tm| style="text-align:right" | 69| style="text-align:right" | 75| 143.97621(43)#| 2.3(9) μs| p| 143Er| (10+)||-id=Thulium-145| 145Tm| style="text-align:right" | 69| style="text-align:right" | 76| 144.97039(21)#| 3.17(20) μs| p| 144Er| (11/2−)||-id=Thulium-146| 146Tm| style="text-align:right" | 69| style="text-align:right" | 77| 145.96666(22)#| 155(20) ms| p| 145Er| (1+)| |-id=Thulium-146m1| style="text-indent:1em" | 146m1Tm| colspan="3" style="text-indent:2em" | 304(6) keV| 73(7) ms| p| 145Er| (5−)| |-id=Thulium-146m2| style="text-indent:1em" | 146m2Tm| colspan="3" style="text-indent:2em" | 437(7) keV| 200(3) ms| p| 145Er| (10+)| |-id=Thulium-147| rowspan=2|147Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 78| rowspan=2|146.9613799(73)| rowspan=2|0.58(3) s| β+ (85%)| 147Er| rowspan=2|11/2−| rowspan=2||-| p (15%)| 146Er|-id=Thulium-147m| style="text-indent:1em" | 147mTm| colspan="3" style="text-indent:2em" | 62(5) keV| 360(40) μs| p| 146Er| 3/2+||-id=Thulium-148| 148Tm| style="text-align:right" | 69| style="text-align:right" | 79| 147.958384(11)| 0.7(2) s| β+| 148Er| (10+)||-id=Thulium-149| rowspan=2|149Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 80| rowspan=2|148.95283(22)#| rowspan=2|0.9(2) s| β+ (99.74%)| 149Er| rowspan=2|11/2−| rowspan=2||-| β+, p (0.26%)| 148Ho|-id=Thulium-150| 150Tm| style="text-align:right" | 69| style="text-align:right" | 81| 149.95009(21)#| 3# s| β+| 150Er| (1+)||-id=Thulium-150m1| rowspan=2 style="text-indent:1em" | 150m1Tm[1] | rowspan=2 colspan="3" style="text-indent:2em" | 140(140)# keV| rowspan=2|2.20(6) s| β+ (98.9%)| 150Er| rowspan=2|(6−)| rowspan=2||-| β+, p (1.1%)| 149Ho|-id=Thulium-150m2| style="text-indent:1em" | 150m2Tm| colspan="3" style="text-indent:2em" | 811(140)# keV| 5.2(3) ms| IT| 150m1Tm| 10+#||-id=Thulium-151| 151Tm| style="text-align:right" | 69| style="text-align:right" | 82| 150.945494(21)| 4.17(11) s| β+| 151Er| (11/2−)||-id=Thulium-151m1| style="text-indent:1em" | 151m1Tm| colspan="3" style="text-indent:2em" | 93(6) keV| 6.6(20) s| β+| 151Er| (1/2+)||-id=Thulium-151m2| style="text-indent:1em" | 151m2Tm| colspan="3" style="text-indent:2em" | 2655.67(22) keV| 451(34) ns| IT| 151Tm| (27/2−)||-id=Thulium-152| 152Tm| style="text-align:right" | 69| style="text-align:right" | 83| 151.944476(58)| 8.0(10) s| β+| 152Er| (2)−||-id=Thulium-152m1| style="text-indent:1em" | 152m1Tm[1] | colspan="3" style="text-indent:2em" | −100(250) keV| 5.2(6) s| β+| 152Er| (9)+||-id=Thulium-152m2| style="text-indent:1em" | 152m2Tm| colspan="3" style="text-indent:2em" | 2455(250) keV| 301(7) ns| IT| 152Tm| (17+)||-id=Thulium-153| rowspan=2|153Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 84| rowspan=2|152.942058(13)| rowspan=2|1.48(1) s| α (91%)| 149Ho| rowspan=2|(11/2−)| rowspan=2||-| β+ (9%)| 153Er|-id=Thulium-153m| rowspan=2 style="text-indent:1em" | 153mTm| rowspan=2 colspan="3" style="text-indent:2em" | 43.2(2) keV| rowspan=2|2.5(2) s| α (92%)| 149Ho| rowspan=2|(1/2+)| rowspan=2||-| β+ (8%)| 153Er|-id=Thulium-154| rowspan=2|154Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 85| rowspan=2|153.941570(15)| rowspan=2|8.1(3) s| β+ (54%)| 154Er| rowspan=2|(2)−| rowspan=2||-| α (46%)| 150Ho|-id=Thulium-154m| rowspan=2 style="text-indent:1em" | 154mTm[1] | rowspan=2 colspan="3" style="text-indent:2em" | 70(50) keV| rowspan=2|3.30(7) s| α (58%)| 150Ho| rowspan=2|(9)+| rowspan=2||-| β+ (42%)| 154Er|-id=Thulium-155| rowspan=2|155Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 86| rowspan=2|154.939210(11)| rowspan=2|21.6(2) s| β+ (99.17%)| 155Er| rowspan=2|11/2−| rowspan=2||-| α (0.83%)| 151Ho|-id=Thulium-155m| style="text-indent:1em" | 155mTm| colspan="3" style="text-indent:2em" | 41(6) keV| 45(4) s| β+| 155Er| 1/2+| |-id=Thulium-156| rowspan=2|156Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 87| rowspan=2|155.938986(15)| rowspan=2|83.8(18) s| β+ (99.94%)| 156Er| rowspan=2|2−| rowspan=2||-| α (0.064%)| 152Er|-id=Thulium-156m| style="text-indent:1em" | 156mTm| colspan="3" style="text-indent:2em" | 400(200)# keV| ~400 ns| IT| 156Tm| (11−)||-id=Thulium-157| rowspan=2|157Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 88| rowspan=2|156.936973(30)| rowspan=2|3.63(9) min| β+| 157Er| rowspan=2|1/2+| rowspan=2||-| α (7.5%)| 153Er|-id=Thulium-157m| style="text-indent:1em" | 157mTm[1] | colspan="3" style="text-indent:2em" | 100(50)# keV| 1.6 s| | | 7/2−#||-id=Thulium-158| 158Tm| style="text-align:right" | 69| style="text-align:right" | 89| 157.936980(27)| 3.98(6) min| β+| 158Er| 2−||-id=Thulium-158m| style="text-indent:1em" | 158mTm[1] | colspan="3" style="text-indent:2em" | 100(50)# keV| ~20 s||| 5−#||-id=Thulium-159| 159Tm| style="text-align:right" | 69| style="text-align:right" | 90| 158.934975(30)| 9.13(16) min| β+| 159Er| 5/2+||-id=Thulium-160| 160Tm| style="text-align:right" | 69| style="text-align:right" | 91| 159.935264(35)| 9.4(3) min| β+| 160Er| 1−||-id=Thulium-160m1| rowspan=2 style="text-indent:1em" | 160m1Tm| rowspan=2 colspan="3" style="text-indent:2em" | 67(14) keV| rowspan=2|74.5(15) s| IT (85%)| 160Tm| rowspan=2|(5+)| rowspan=2||-| β+ (15%)| 160Er|-id=Thulium-160m2| style="text-indent:1em" | 160m2Tm| colspan="3" style="text-indent:2em" | 215(52)# keV| ~200 ns| IT| 160Tm| (8)||-id=Thulium-161| 161Tm| style="text-align:right" | 69| style="text-align:right" | 92| 160.933549(30)| 30.2(8) min| β+| 161Er| 7/2+||-id=Thulium-161m1| style="text-indent:1em" | 161m1Tm| colspan="3" style="text-indent:2em" | 7.51(24) keV| 5# min||| (1/2+)||-id=Thulium-161m2| style="text-indent:1em" | 161m2Tm| colspan="3" style="text-indent:2em" | 78.20(3) keV| 110(3) ns| IT| 161Tm| 7/2−||-id=Thulium-162| 162Tm| style="text-align:right" | 69| style="text-align:right" | 93| 161.934001(28)| 21.70(19) min| β+| 162Er| 1−||-id=Thulium-162m| rowspan=2 style="text-indent:1em" | 162mTm| rowspan=2 colspan="3" style="text-indent:2em" | 130(40) keV| rowspan=2|24.3(17) s| IT (81%)| 162Tm| rowspan=2|5+| rowspan=2||-| β+ (19%)| 162Er|-id=Thulium-163| 163Tm| style="text-align:right" | 69| style="text-align:right" | 94| 162.9326583(59)| 1.810(5) h| β+| 163Er| 1/2+||-id=Thulium-163m| style="text-indent:1em" | 163mTm| colspan="3" style="text-indent:2em" | 86.92(5) keV| 380(30) ns| IT| 163Tm| (7/2)−||-id=Thulium-164| rowspan=2|164Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 95| rowspan=2|163.933538(27)| rowspan=2|2.0(1) min| EC (61%)| rowspan=2|164Er| rowspan=2|1+| rowspan=2||-| β+ (39%)|-id=Thulium-164m| rowspan=2 style="text-indent:1em" | 164mTm| rowspan=2 colspan="3" style="text-indent:2em" | 20(12) keV| rowspan=2|5.1(1) min| IT (~80%)| 164Tm| rowspan=2|6−| rowspan=2||-| β+ (~20%)| 164Er|-id=Thulium-165| 165Tm| style="text-align:right" | 69| style="text-align:right" | 96| 164.9324418(18)| 30.06(3) h| β+| 165Er| 1/2+||-id=Thulium-165m1| style="text-indent:1em" | 165m1Tm| colspan="3" style="text-indent:2em" | 80.37(6) keV| 80(3) μs| IT| 165Tm| 7/2+||-id=Thulium-165m2| style="text-indent:1em" | 165m2Tm| colspan="3" style="text-indent:2em" | 160.47(6) keV| 9.0(5) μs| IT| 165Tm| 7/2−||-id=Thulium-166| 166Tm| style="text-align:right" | 69| style="text-align:right" | 97| 165.933562(12)| 7.70(3) h| β+| 166Er| 2+||-id=Thulium-166m1| style="text-indent:1em" | 166m1Tm| colspan="3" style="text-indent:2em" | 122(7) keV| 348(21) ms| IT| 166Tm| (6−)||-id=Thulium-166m2| style="text-indent:1em" | 166m2Tm| colspan="3" style="text-indent:2em" | 244(7) keV| 2(1) μs| IT| 166Tm| (6−)||-id=Thulium-167| 167Tm| style="text-align:right" | 69| style="text-align:right" | 98| 166.9328572(14)| 9.25(2) d| EC| 167Er| 1/2+||-id=Thulium-167m1| style="text-indent:1em" | 167m1Tm| colspan="3" style="text-indent:2em" | 179.480(19) keV| 1.16(6) μs| IT| 167Tm| 7/2+||-id=Thulium-167m2| style="text-indent:1em" | 167m2Tm| colspan="3" style="text-indent:2em" | 292.820(20) keV| 0.9(1) μs| IT| 167Tm| 7/2−||-id=Thulium-168| rowspan=2|168Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 99| rowspan=2|167.9341785(18)| rowspan=2|93.1(2) d| β+ (99.99%)| 168Er| rowspan=2|3+| rowspan=2||-| β− (0.010%)| 168Yb|-id=Thulium-169| 169Tm| style="text-align:right" | 69| style="text-align:right" | 100| 168.93421896(79)| colspan=3 align=center|Observationally Stable[2] | 1/2+| 1.0000|-id=Thulium-169m| style="text-indent:1em" | 169mTm| colspan="3" style="text-indent:2em" | 316.1463(1) keV| 659.9(23) ns| IT| 169Tm| 7/2+||-| rowspan=2|170Tm| rowspan=2 style="text-align:right" | 69| rowspan=2 style="text-align:right" | 101| rowspan=2|169.93580709(79)| rowspan=2|128.6(3) d| β− (99.87%)| 170Yb| rowspan=2|1−| rowspan=2||-| EC (0.131%)| 170Er|-id=Thulium-170m| style="text-indent:1em" | 170mTm| colspan="3" style="text-indent:2em" | 183.197(4) keV| 4.12(13) μs| IT| 170Tm| 3+||-id=Thulium-171| 171Tm| style="text-align:right" | 69| style="text-align:right" | 102| 170.9364352(10)| 1.92(1) y| β−| 171Yb| 1/2+||-id=Thulium-171m1| style="text-indent:1em" | 171m1Tm| colspan="3" style="text-indent:2em" | 424.9557(15) keV| 2.60(2) μs| IT| 171Tm| 7/2−||-id=Thulium-171m2| style="text-indent:1em" | 171m2Tm| colspan="3" style="text-indent:2em" | 1674.43(13) keV| 1.7(2) μs| IT| 171Tm| 19/2+||-id=Thulium-172| 172Tm| style="text-align:right" | 69| style="text-align:right" | 103| 171.9384070(59)| 63.6(3) h| β−| 172Yb| 2−||-id=Thulium-172m| style="text-indent:1em" | 172mTm| colspan="3" style="text-indent:2em" | 476.2(2) keV| 132(7) μs| IT| 172Tm| (6+)||-id=Thulium-173| 173Tm| style="text-align:right" | 69| style="text-align:right" | 104| 172.9396066(47)| 8.24(8) h| β−| 173Yb| (1/2+)||-id=Thulium-173m1| style="text-indent:1em" | 173m1Tm| colspan="3" style="text-indent:2em" | 317.73(20) keV| 10.7(17) μs| IT| 173Tm| 7/2−||-id=Thulium-173m2| style="text-indent:1em" | 173m2Tm| colspan="3" style="text-indent:2em" | 1905.7(4) keV| 250(69) ns| IT| 173Tm| 19/2−||-id=Thulium-173m3| style="text-indent:1em" | 173m3Tm| colspan="3" style="text-indent:2em" | 4047.9(5) keV| 121(28) ns| IT| 173Tm| 35/2−||-id=Thulium-174| 174Tm| style="text-align:right" | 69| style="text-align:right" | 105| 173.942174(48)| 5.4(1) min| β−| 174Yb| 4−||-id=Thulium-174m1| rowspan=2 style="text-indent:1em" | 174m1Tm| rowspan=2 colspan="3" style="text-indent:2em" | 252.4(7) keV| rowspan=2|2.29(1) s| IT (>98.5%)| 174Tm| rowspan=2|0+| rowspan=2||-| β− (<1.5%)| 174Yb|-id=Thulium-174m2| style="text-indent:1em" | 174m2Tm| colspan="3" style="text-indent:2em" | 2091.7(3) keV| 106(7) μs| IT| 174Tm| 14−||-id=Thulium-175| 175Tm| style="text-align:right" | 69| style="text-align:right" | 106| 174.943842(54)| 15.2(5) min| β−| 175Yb| (1/2)+||-id=Thulium-175m1| style="text-indent:1em" | 175m1Tm| colspan="3" style="text-indent:2em" | 440.0(11) keV| 319(35) ns| IT| 175Tm| 7/2−||-id=Thulium-175m2| style="text-indent:1em" | 175m2Tm| colspan="3" style="text-indent:2em" | 1517.7(12) keV| 21(14) μs| IT| 175Tm| 23/2+||-id=Thulium-176| 176Tm| style="text-align:right" | 69| style="text-align:right" | 107| 175.94700(11)| 1.85(3) min| β−| 176Yb| (4+)||-id=Thulium-177| 177Tm| style="text-align:right" | 69| style="text-align:right" | 108| 176.94893(22)#| 95(7) s| β−| 177Yb| 1/2+#||-id=Thulium-177m| style="text-indent:1em" | 177mTm[1] | colspan="3" style="text-indent:2em" | 100(100)# keV| 77(11) s| β−| 177Yb| 7/2−#||-id=Thulium-178| 178Tm| style="text-align:right" | 69| style="text-align:right" | 109| 177.95251(32)#| 10# s
[>300&nbsp;ns]| | | 1−#||-id=Thulium-179| 179Tm| style="text-align:right" | 69| style="text-align:right" | 110| 178.95502(43)#| 18# s
[>300&nbsp;ns]| | | 1/2+#||-id=Thulium-180| 180Tm| style="text-align:right" | 69| style="text-align:right" | 111| 179.95902(43)#| 3# s
[>300&nbsp;ns]| | | ||-id=Thulium-181| 181Tm| style="text-align:right" | 69| style="text-align:right" | 112| 180.96195(54)#| 7# s
[>300&nbsp;ns]| | | 1/2+#||-id=Thulium-182| 182Tm[3] | style="text-align:right" | 69| style="text-align:right" | 113| 181.96619(54)#| | | | ||-id=Thulium-183| 183Tm[3] | style="text-align:right" | 69| style="text-align:right" | 114| | | | | |

Thulium-170

See main article: Thulium-170. Thulium-170 has a half-life of 128.6 days, decaying by β− decay about 99.87% of the time and electron capture the remaining 0.13% of the time. Due to its low-energy X-ray emissions, it has been proposed for radiotherapy[4] and as a source in a radiothermal generator.[5]

References

Notes and References

  1. Order of ground state and isomer is uncertain.
  2. Believed to undergo α decay to 165Ho
  3. O. B. . Tarasov . A. . Gade . K. . Fukushima . et al. . Observation of New Isotopes in the Fragmentation of 198Pt at FRIB . Physical Review Letters . 132 . 072501 . 2024 . 10.1103/PhysRevLett.132.072501.
  4. Polyak . Andras . Das . Tapas . Chakraborty . Sudipta . Kiraly . Reka . Dabasi . Gabriella . Joba . Robert Peter . Jakab . Csaba . Thuroczy . Julianna . Postenyi . Zita . Haasz . Veronika . Janoki . Gergely . Janoki . Gyozo A. . Pillai . Maroor R.A. . Balogh . Lajos . Thulium-170-Labeled Microparticles for Local Radiotherapy: Preliminary Studies . Cancer Biotherapy and Radiopharmaceuticals . October 2014 . 29 . 8 . 330–338 . 10.1089/cbr.2014.1680 . 25226213 . . en . 1084-9785.
  5. Dustin . J. Seth . Borrelli . R.A. . Assessment of alternative radionuclides for use in a radioisotope thermoelectric generator . Nuclear Engineering and Design . December 2021 . 385 . 111475 . 10.1016/j.nucengdes.2021.111475. free .

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