Isotopes of iridium explained

There are two natural isotopes of iridium (77Ir), and 37 radioisotopes, the most stable radioisotope being 192Ir with a half-life of 73.83 days, and many nuclear isomers, the most stable of which is 192m2Ir with a half-life of 241 years. All other isomers have half-lives under a year, most under a day. All isotopes of iridium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.[1]

List of isotopes

|-| 164Ir[2] | style="text-align:right" | 77| style="text-align:right" | 87| 163.99220(44)#| <0.5 μs| p?| 163Os| 2−#|||-| rowspan=2 style="text-indent:1em" | 164mIr| rowspan=2 colspan="3" style="text-indent:2em" | 270(110)# keV| rowspan=2| 70(10) μs| p (96%)| 163Os| rowspan=2| 9+#| rowspan=2|| rowspan=2||-| α (4%)| 160mRe|-| 165Ir| style="text-align:right" | 77| style="text-align:right" | 88| 164.98752(23)#| [3] | p| 164Os| (1/2+)| | |-| rowspan=2 style="text-indent:1em" | 165mIr[4] | rowspan=2 colspan="3" style="text-indent:2em" | ~255 keV| rowspan=2|340(40) μs| p (88%)| 164Os| rowspan=2|(11/2−)| rowspan=2|| rowspan=2||-| α (12%)| 161mRe|-| rowspan=2|166Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 89| rowspan=2|165.98582(22)#| rowspan=2|10.5(22) ms| α (93%)| 162Re| rowspan=2|(2−)| rowspan=2|| rowspan=2||-| p (7%)| 165Os|-| rowspan=2 style="text-indent:1em" | 166mIr| rowspan=2 colspan="3" style="text-indent:2em" | 172(6) keV| rowspan=2|15.1(9) ms| α (98.2%)| 162Re| rowspan=2|(9+)| rowspan=2|| rowspan=2||-| p (1.8%)| 165Os|-| rowspan=3|167Ir| rowspan=3 style="text-align:right" | 77| rowspan=3 style="text-align:right" | 90| rowspan=3|166.981665(20)| rowspan=3|35.2(20) ms| α (48%)| 163Re| rowspan=3|1/2+| rowspan=3|| rowspan=3||-| p (32%)| 166Os|-| β+ (20%)| 167Os|-| rowspan=3 style="text-indent:1em" | 167mIr| rowspan=3 colspan="3" style="text-indent:2em" | 175.3(22) keV| rowspan=3|30.0(6) ms| α (80%)| 163Re| rowspan=3|11/2−| rowspan=3|| rowspan=3||-| β+ (20%)| 167Os|-| p (.4%)| 166Os|-| rowspan=2|168Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 91| rowspan=2|167.97988(16)#| rowspan=2|161(21) ms| α| 164Re| rowspan=2|(2-)| rowspan=2|| rowspan=2||-| β+ (rare)| 168Os|-| style="text-indent:1em" | 168mIr| colspan="3" style="text-indent:2em" | 50(100)# keV| 125(40) ms| α| 164Re| (9+)|||-| rowspan=2|169Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 92| rowspan=2|168.976295(28)| rowspan=2|780(360) ms
[0.64(+46−24)&nbsp;s]| α| 165Re| rowspan=2|(1/2+)| rowspan=2|| rowspan=2||-| β+ (rare)| 169Os|-| rowspan=2 style="text-indent:1em" | 169mIr| rowspan=2 colspan="3" style="text-indent:2em" | 154(24) keV| rowspan=2|308(22) ms| α (72%)| 165Re| rowspan=2|(11/2−)| rowspan=2|| rowspan=2||-| β+ (28%)| 169Os|-| rowspan=2|170Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 93| rowspan=2|169.97497(11)#| rowspan=2|910(150) ms
[0.87(+18−12)&nbsp;s]| β+ (64%)| 170Os| rowspan=2|low#| rowspan=2|| rowspan=2||-| α (36%)| 166Re|-| rowspan=3 style="text-indent:1em" | 170mIr| rowspan=3 colspan="3" style="text-indent:2em" | 160(50)# keV| rowspan=3|440(60) ms| α (36%)| 166Re| rowspan=3|(8+)| rowspan=3|| rowspan=3||-| β+| 170Os|-| IT| 170Ir|-| rowspan=2|171Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 94| rowspan=2|170.97163(4)| rowspan=2|3.6(10) s
[3.2(+13−7)&nbsp;s]| α (58%)| 167Re| rowspan=2|1/2+| rowspan=2|| rowspan=2||-| β+ (42%)| 171Os|-| style="text-indent:1em" | 171mIr| colspan="3" style="text-indent:2em" | 180(30)# keV| 1.40(10) s||| (11/2−)|||-| rowspan=2|172Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 95| rowspan=2|171.970610(30)| rowspan=2|4.4(3) s| β+ (98%)| 172Os| rowspan=2|(3+)| rowspan=2|| rowspan=2||-| α (2%)| 168Re|-| rowspan=2 style="text-indent:1em" | 172mIr| rowspan=2 colspan="3" style="text-indent:2em" | 280(100)# keV| rowspan=2|2.0(1) s| β+ (77%)| 172Os| rowspan=2|(7+)| rowspan=2|| rowspan=2||-| α (23%)| 168Re|-| rowspan=2|173Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 96| rowspan=2|172.967502(15)| rowspan=2|9.0(8) s| β+ (93%)| 173Os| rowspan=2|(3/2+,5/2+)| rowspan=2|| rowspan=2||-| α (7%)| 169Re|-| rowspan=2 style="text-indent:1em" | 173mIr| rowspan=2 colspan="3" style="text-indent:2em" | 253(27) keV| rowspan=2|2.20(5) s| β+ (88%)| 173Os| rowspan=2|(11/2−)| rowspan=2|| rowspan=2||-| α (12%)| 169Re|-| rowspan=2|174Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 97| rowspan=2|173.966861(30)| rowspan=2|7.9(6) s| β+ (99.5%)| 174Os| rowspan=2|(3+)| rowspan=2|| rowspan=2||-| α (.5%)| 170Re|-| rowspan=2 style="text-indent:1em" | 174mIr| rowspan=2 colspan="3" style="text-indent:2em" | 193(11) keV| rowspan=2|4.9(3) s| β+ (99.53%)| 174Os| rowspan=2|(7+)| rowspan=2|| rowspan=2||-| α (.47%)| 170Re|-| rowspan=2|175Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 98| rowspan=2|174.964113(21)| rowspan=2|9(2) s| β+ (99.15%)| 175Os| rowspan=2|(5/2−)| rowspan=2|| rowspan=2||-| α (.85%)| 171Re|-| rowspan=2|176Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 99| rowspan=2|175.963649(22)| rowspan=2|8.3(6) s| β+ (97.9%)| 176Os| rowspan=2|| rowspan=2|| rowspan=2||-| α (2.1%)| 172Re|-| rowspan=2|177Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 100| rowspan=2|176.961302(21)| rowspan=2|30(2) s| β+ (99.94%)| 177Os| rowspan=2|5/2−| rowspan=2|| rowspan=2||-| α (.06%)| 173Re|-| 178Ir| style="text-align:right" | 77| style="text-align:right" | 101| 177.961082(21)| 12(2) s| β+| 178Os||||-| 179Ir| style="text-align:right" | 77| style="text-align:right" | 102| 178.959122(12)| 79(1) s| β+| 179Os| (5/2)−|||-| 180Ir| style="text-align:right" | 77| style="text-align:right" | 103| 179.959229(23)| 1.5(1) min| β+| 180Os| (4,5)(+#)|||-| 181Ir| style="text-align:right" | 77| style="text-align:right" | 104| 180.957625(28)| 4.90(15) min| β+| 181Os| (5/2)−|||-| 182Ir| style="text-align:right" | 77| style="text-align:right" | 105| 181.958076(23)| 15(1) min| β+| 182Os| (3+)|||-| rowspan=2|183Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 106| rowspan=2|182.956846(27)| rowspan=2|57(4) min| β+ (99.95%)| 183Os| rowspan=2|5/2−| rowspan=2|| rowspan=2||-| α (.05%)| 179Re|-| 184Ir| style="text-align:right" | 77| style="text-align:right" | 107| 183.95748(3)| 3.09(3) h| β+| 184Os| 5−|||-| style="text-indent:1em" | 184m1Ir| colspan="3" style="text-indent:2em" | 225.65(11) keV| 470(30) μs||| 3+|||-| style="text-indent:1em" | 184m2Ir| colspan="3" style="text-indent:2em" | 328.40(24) keV| 350(90) ns||| (7)+|||-| 185Ir| style="text-align:right" | 77| style="text-align:right" | 108| 184.95670(3)| 14.4(1) h| β+| 185Os| 5/2−|||-| 186Ir| style="text-align:right" | 77| style="text-align:right" | 109| 185.957946(18)| 16.64(3) h| β+| 186Os| 5+|||-| rowspan=2 style="text-indent:1em" | 186mIr| rowspan=2 colspan="3" style="text-indent:2em" | 0.8(4) keV| rowspan=2|1.92(5) h| β+| 186Os| rowspan=2|2−| rowspan=2|| rowspan=2||-| IT (rare)| 186Ir|-| 187Ir| style="text-align:right" | 77| style="text-align:right" | 110| 186.957363(7)| 10.5(3) h| β+| 187Os| 3/2+|||-| style="text-indent:1em" | 187m1Ir| colspan="3" style="text-indent:2em" | 186.15(4) keV| 30.3(6) ms| IT| 187Ir| 9/2−|||-| style="text-indent:1em" | 187m2Ir| colspan="3" style="text-indent:2em" | 433.81(9) keV| 152(12) ns||| 11/2−|||-| 188Ir| style="text-align:right" | 77| style="text-align:right" | 111| 187.958853(8)| 41.5(5) h| β+| 188Os| 1−|||-| rowspan=2 style="text-indent:1em" | 188mIr| rowspan=2 colspan="3" style="text-indent:2em" | 970(30) keV| rowspan=2|4.2(2) ms| IT| 188Ir| rowspan=2|7+#| rowspan=2|| rowspan=2||-| β+ (rare)| 188Os|-| 189Ir| style="text-align:right" | 77| style="text-align:right" | 112| 188.958719(14)| 13.2(1) d| EC| 189Os| 3/2+|||-| style="text-indent:1em" | 189m1Ir| colspan="3" style="text-indent:2em" | 372.18(4) keV| 13.3(3) ms| IT| 189Ir| 11/2−|||-| style="text-indent:1em" | 189m2Ir| colspan="3" style="text-indent:2em" | 2333.3(4) keV| 3.7(2) ms||| (25/2)+|||-| rowspan=2|190Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 113| rowspan=2|189.9605460(18)| rowspan=2|11.78(10) d| EC| rowspan=2|190Os| rowspan=2|4−| rowspan=2 ||-| β+ (<0.002%)|-| style="text-indent:1em" | 190m1Ir| colspan="3" style="text-indent:2em" | 26.1(1) keV| 1.120(3) h| IT| 190Ir| (1−)|||-| style="text-indent:1em" | 190m2Ir| colspan="3" style="text-indent:2em" | 36.154(25) keV| >2 μs||| (4)+|||-| style="text-indent:1em" | 190m3Ir| colspan="3" style="text-indent:2em" | 376.4(1) keV| 3.087(12) h||| (11)−|||-| 191Ir| style="text-align:right" | 77| style="text-align:right" | 114| 190.9605940(18)| colspan=3 align=center|Observationally Stable[5] | 3/2+| 0.373(2)||-| style="text-indent:1em" | 191m1Ir| colspan="3" style="text-indent:2em" | 171.24(5) keV| 4.94(3) s| IT| 191Ir| 11/2−|||-| style="text-indent:1em" | 191m2Ir| colspan="3" style="text-indent:2em" | 2120(40) keV| 5.5(7) s||||||-| rowspan=2|192Ir| rowspan=2 style="text-align:right" | 77| rowspan=2 style="text-align:right" | 115| rowspan=2|191.9626050(18)| rowspan=2|73.827(13) d| β− (95.24%)| 192Pt| rowspan=2|4+| rowspan=2|| rowspan=2||-| EC (4.76%)| 192Os|-| rowspan=2 style="text-indent:1em" | 192m1Ir| rowspan=2 colspan="3" style="text-indent:2em" | 56.720(5) keV| rowspan=2|1.45(5) min| IT (98.25%)| 192Ir| rowspan=2|1−| rowspan=2|| rowspan=2||-| β− (1.75%)| 192Pt|-| style="text-indent:1em" | 192m2Ir| colspan="3" style="text-indent:2em" | 168.14(12) keV| 241(9) y| IT| 192Ir| (11−)|||-| 193Ir| style="text-align:right" | 77| style="text-align:right" | 116| 192.9629264(18)| colspan=3 align=center|Observationally Stable[6] | 3/2+| 0.627(2)||-| style="text-indent:1em" | 193mIr| colspan="3" style="text-indent:2em" | 80.240(6) keV| 10.53(4) d| IT| 193Ir| 11/2−|||-| 194Ir| style="text-align:right" | 77| style="text-align:right" | 117| 193.9650784(18)| 19.28(13) h| β−| 194Pt| 1−|||-| style="text-indent:1em" | 194m1Ir| colspan="3" style="text-indent:2em" | 147.078(5) keV| 31.85(24) ms| IT| 194Ir| (4+)|||-| style="text-indent:1em" | 194m2Ir| colspan="3" style="text-indent:2em" | 370(70) keV| 171(11) d||| (10,11)(−#)|||-| 195Ir| style="text-align:right" | 77| style="text-align:right" | 118| 194.9659796(18)| 2.5(2) h| β−| 195Pt| 3/2+|||-| rowspan=2 style="text-indent:1em" | 195mIr| rowspan=2 colspan="3" style="text-indent:2em" | 100(5) keV| rowspan=2|3.8(2) h| β− (95%)| 195Pt| rowspan=2|11/2−| rowspan=2| | rowspan=2||-| IT (5%)| 195Ir|-| 196Ir| style="text-align:right" | 77| style="text-align:right" | 119| 195.96840(4)| 52(1) s| β−| 196Pt| (0−)|||-| rowspan=2 style="text-indent:1em" | 196mIr| rowspan=2 colspan="3" style="text-indent:2em" | 210(40) keV| rowspan=2|1.40(2) h| β− (99.7%)| 196Pt| rowspan=2|(10,11−)| rowspan=2|| rowspan=2||-| IT| 196Ir|-| 197Ir| style="text-align:right" | 77| style="text-align:right" | 120| 196.969653(22)| 5.8(5) min| β−| 197Pt| 3/2+|||-| rowspan=2 style="text-indent:1em" | 197mIr| rowspan=2 colspan="3" style="text-indent:2em" | 115(5) keV| rowspan=2|8.9(3) min| β− (99.75%)| 197Pt| rowspan=2|11/2−| rowspan=2|| rowspan=2||-| IT (.25%)| 197Ir|-| 198Ir| style="text-align:right" | 77| style="text-align:right" | 121| 197.97228(21)#| 8(1) s| β−| 198Pt||||-| 199Ir| style="text-align:right" | 77| style="text-align:right" | 122| 198.97380(4)| 7(5) s| β−| 199Pt| 3/2+#|||-| style="text-indent:1em" | 199mIr| colspan="3" style="text-indent:2em" | 130(40)# keV| 235(90) ns| IT| 199Ir| 11/2−#|||-| 200Ir| style="text-align:right" | 77| style="text-align:right" | 123| 199.976800(210)#| 43(6) s| β−| 200Pt| (2-, 3-)|||-| 201Ir| style="text-align:right" | 77| style="text-align:right" | 124| 200.978640(210)#| 21(5) s| β−| 201Pt| (3/2+)|||-| 202Ir| style="text-align:right" | 77| style="text-align:right" | 125| 201.981990(320)#| 11(3) s| β−| 202Pt| (2-)|||-| style="text-indent:1em" | 202mIr| colspan="3" style="text-indent:2em" | 2000(1000)# keV| 3.4(0.6) μs| IT| 202Ir|||

Iridium-192

See main article: article and Iridium-192.

Iridium-192 (symbol 192Ir) is a radioactive isotope of iridium, with a half-life of 73.83 days.[7] It decays by emitting beta (β) particles and gamma (γ) radiation. About 96% of 192Ir decays occur via emission of β and γ radiation, leading to 192Pt. Some of the β particles are captured by other 192Ir nuclei, which are then converted to 192Os. Electron capture is responsible for the remaining 4% of 192Ir decays.[8] Iridium-192 is normally produced by neutron activation of natural-abundance iridium metal.[9]

Iridium-192 is a very strong gamma ray emitter, with a gamma dose-constant of approximately 1.54 μSv·h−1·MBq−1 at 30 cm, and a specific activity of 341 TBq·g−1 (9.22 kCi·g−1).[10] [11] There are seven principal energy packets produced during its disintegration process ranging from just over 0.2 to about 0.6 MeV.

The 192m2Ir isomer is unusual, both for its long half-life for an isomer, and that said half-life greatly exceeds that of the ground state of the same isotope.

References

External links

Notes and References

  1. Belli . P. . Bernabei . R. . Danevich . F. A. . Incicchitti . A. . Tretyak . V. I. . 3 . Experimental searches for rare alpha and beta decays . European Physical Journal A . 2019 . 55 . 8 . 140–1–140–7 . 10.1140/epja/i2019-12823-2 . 1434-601X . 1908.11458. 2019EPJA...55..140B . 201664098 .
  2. Drummond . M. C. . O'Donnell . D. . Page . R. D. . Joss . D. T. . Capponi . L. . Cox . D. M. . Darby . I. G. . Donosa . L. . Filmer . F. . Grahn . T. . Greenlees . P. T. . Hauschild . K. . Herzan . A. . Jakobsson . U. . Jones . P. M. . Julin . R. . Juutinen . S. . Ketelhut . S. . Leino . M. . Lopez-Martens . A. . Mistry . A. K. . Nieminen . P. . Peura . P. . Rahkila . P. . Rinta-Antila . S. . Ruotsalainen . P. . Sandzelius . M. . Sarén . J. . Sayğı . B. . Scholey . C. . Simpson . J. . Sorri . J. . Thornthwaite . A. . Uusitalo . J. . α decay of the π h 11 / 2 isomer in Ir 164 . Physical Review C . 16 June 2014 . 89 . 6 . 064309 . 10.1103/PhysRevC.89.064309 . 2014PhRvC..89f4309D . 21 June 2023 . en . 0556-2813.
  3. Web site: Hilton . Joshua Ben . Decays of new nuclides 169Au, 170Hg, 165Pt and the ground state of 165Ir discovered using MARA . University of Liverpool . 21 June 2023. .
  4. Drummond . M. C. . O'Donnell . D. . Page . R. D. . Joss . D. T. . Capponi . L. . Cox . D. M. . Darby . I. G. . Donosa . L. . Filmer . F. . Grahn . T. . Greenlees . P. T. . Hauschild . K. . Herzan . A. . Jakobsson . U. . Jones . P. M. . Julin . R. . Juutinen . S. . Ketelhut . S. . Leino . M. . Lopez-Martens . A. . Mistry . A. K. . Nieminen . P. . Peura . P. . Rahkila . P. . Rinta-Antila . S. . Ruotsalainen . P. . Sandzelius . M. . Sarén . J. . Sayğı . B. . Scholey . C. . Simpson . J. . Sorri . J. . Thornthwaite . A. . Uusitalo . J. . α decay of the π h 11 / 2 isomer in Ir 164 . Physical Review C . 16 June 2014 . 89 . 6 . 064309 . 10.1103/PhysRevC.89.064309 . 2014PhRvC..89f4309D . 21 June 2023 . en . 0556-2813.
  5. Believed to undergo α decay to 187Re
  6. Believed to undergo α decay to 189Re
  7. Web site: Radioisotope Brief: Iridium-192 (Ir-192). 20 March 2012.
  8. Baggerly . Leo L.. The radioactive decay of Iridium-192 . Ph.D. . 1956. California Institute of Technology. Pasadena, Calif.. 1, 2, 7. 10.7907/26VA-RB25.
  9. Web site: Isotope Supplier: Stable Isotopes and Radioisotopes from ISOFLEX - Iridium-192. www.isoflex.com. en. 2017-10-11.
  10. Delacroix . D . Guerre . J P . Leblanc . P . Hickman . C . Radionuclide and Radiation Protection Data Handbook . Radiation Protection Dosimetry . 2002 . 98 . 1 . 9–168 . Nuclear Technology Publishing . Ashford, Kent . 10.1093/OXFORDJOURNALS.RPD.A006705 . 11916063 . 1870965876 . 123447679 . 2nd . https://web.archive.org/web/20190822130507/https://pdfs.semanticscholar.org/fbb1/7281dae98db83fe20df96b9d879c0c73b199.pdf . dead . 2019-08-22 .
  11. Unger . L M . Trubey . D K . Specific Gamma-Ray Dose Constants for Nuclides Important to Dosimetry and Radiological Assessment . Oak Ridge National Laboratory. May 1982 . https://web.archive.org/web/20180322020815/https://www.orau.org/documents/ivhp/health-physics/ornl-rsic-45.pdf . 22 March 2018.

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