Isotopes of calcium#Calcium-52

Calcium ({{sub|20}}Ca) has 26 known isotopes, ranging from {{sup|35}}Ca to {{sup|60}}Ca. There are five stable isotopes ({{sup|40}}Ca, {{sup|42}}Ca, {{sup|43}}Ca, {{sup|44}}Ca and {{sup|46}}Ca), plus one isotope (Calcium-48) with such a long half-life that it is for all practical purposes stable. The most abundant isotope, {{sup|40}}Ca, as well as the rare {{sup|46}}Ca, are theoretically unstable on energetic grounds, but their decay has not been observed. Calcium also has a cosmogenic isotope, {{sup|41}}Ca, with half-life 99,400 years. Unlike cosmogenic isotopes that are produced in the air, {{sup|41}}Ca is produced by neutron activation of {{sup|40}}Ca. Most of its production is in the upper metre of the soil column, where the cosmogenic neutron flux is still strong enough. {{sup|41}}Ca has received much attention in stellar studies because it decays to {{sup|41}}K, a critical indicator of solar system anomalies. The most stable artificial isotopes are {{sup|45}}Ca with half-life 163 days and {{sup|47}}Ca with half-life 4.5 days. All other calcium isotopes have half-lives of minutes or less.{{Nubase 2016}}

Stable {{sup|40}}Ca comprises about 97% of natural calcium and is mainly created by nucleosynthesis in large stars. Similarly to {{sup|40}}Ar, however, some atoms of {{sup|40}}Ca are radiogenic, created through the radioactive decay of {{sup|40}}K. While K–Ar dating has been used extensively in the geological sciences, the prevalence of {{sup|40}}Ca in nature initially impeded the proliferation of K-Ca dating in early studies, with only a handful of studies in the 20th century. Modern techniques using increasingly precise Thermal-Ionization (TIMS) and Collision-Cell Multi-Collector Inductively-coupled plasma mass spectrometry (CC-MC-ICP-MS) techniques, however, have been used for successful K–Ca age dating,{{Cite journal |last1=Marshall |first1=B. D. |last2=DePaolo |first2=D. J. |date=1982-12-01 |title=Precise age determinations and petrogenetic studies using the KCa method |url=https://www.sciencedirect.com/science/article/abs/pii/0016703782903763 |journal=Geochimica et Cosmochimica Acta |volume=46 |issue=12 |pages=2537–2545 |doi=10.1016/0016-7037(82)90376-3 |issn=0016-7037}}{{Cite web |last=admin |title=K-Ca dating and Ca isotope composition of the oldest Solar System lava, Erg Chech 002 {{!}} Geochemical Perspectives Letters |url=https://www.geochemicalperspectivesletters.org/article2302/ |access-date=2024-10-16 |language=en-US}} as well as determining K losses from the lower continental crust{{Cite web |last=admin |title=Radiogenic Ca isotopes confirm post-formation K depletion of lower crust {{!}} Geochemical Perspectives Letters |url=https://www.geochemicalperspectivesletters.org/article1904/ |access-date=2024-10-16 |language=en-US}} and for source-tracing calcium contributions from various geologic reservoirs{{Cite journal |last1=Antonelli |first1=Michael A. |last2=DePaolo |first2=Donald J. |last3=Christensen |first3=John N. |last4=Wotzlaw |first4=Jörn-Frederik |last5=Pester |first5=Nicholas J. |last6=Bachmann |first6=Olivier |date=2021-09-16 |title=Radiogenic 40 Ca in Seawater: Implications for Modern and Ancient Ca Cycles |url=https://pubs.acs.org/doi/10.1021/acsearthspacechem.1c00179 |journal=ACS Earth and Space Chemistry |language=en |volume=5 |issue=9 |pages=2481–2492 |doi=10.1021/acsearthspacechem.1c00179 |issn=2472-3452}}{{Cite journal |last1=Davenport |first1=Jesse |last2=Caro |first2=Guillaume |last3=France-Lanord |first3=Christian |date=2022-12-01 |title=Decoupling of physical and chemical erosion in the Himalayas revealed by radiogenic Ca isotopes |url=https://www.sciencedirect.com/science/article/abs/pii/S0016703722005804 |journal=Geochimica et Cosmochimica Acta |volume=338 |pages=199–219 |doi=10.1016/j.gca.2022.10.031 |issn=0016-7037}} similar to Rb-Sr.

Stable isotope variations of calcium (most typically {{sup|44}}Ca/{{sup|40}}Ca or ⁴⁴Ca/⁴²Ca, denoted as 'δ{{sup|44}}Ca' and 'δ{{sup|44/42}}Ca' in delta notation) are also widely used across the natural sciences for a number of applications, ranging from early determination of osteoporosis{{Cite journal |last1=Eisenhauer |first1=A. |last2=Müller |first2=M. |last3=Heuser |first3=A. |last4=Kolevica |first4=A. |last5=Glüer |first5=C. -C. |last6=Both |first6=M. |last7=Laue |first7=C. |last8=Hehn |first8=U. v. |last9=Kloth |first9=S. |last10=Shroff |first10=R. |last11=Schrezenmeir |first11=J. |date=2019-06-01 |title=Calcium isotope ratios in blood and urine: A new biomarker for the diagnosis of osteoporosis |journal=Bone Reports |volume=10 |pages=100200 |doi=10.1016/j.bonr.2019.100200 |pmid=30997369 |pmc=6453776 |issn=2352-1872}} to quantifying volcanic eruption timescales.{{Cite journal |last1=Antonelli |first1=Michael A. |last2=Mittal |first2=Tushar |last3=McCarthy |first3=Anders |last4=Tripoli |first4=Barbara |last5=Watkins |first5=James M. |last6=DePaolo |first6=Donald J. |date=2019-10-08 |title=Ca isotopes record rapid crystal growth in volcanic and subvolcanic systems |journal=Proceedings of the National Academy of Sciences |language=en |volume=116 |issue=41 |pages=20315–20321 |doi=10.1073/pnas.1908921116 |doi-access=free |issn=0027-8424 |pmc=6789932 |pmid=31548431}} Other applications include: quantifying carbon sequestration efficiency in CO₂ injection sites{{Cite journal |last1=Pogge von Strandmann |first1=Philip A. E. |last2=Burton |first2=Kevin W. |last3=Snæbjörnsdóttir |first3=Sandra O. |last4=Sigfússon |first4=Bergur |last5=Aradóttir |first5=Edda S. |last6=Gunnarsson |first6=Ingvi |last7=Alfredsson |first7=Helgi A. |last8=Mesfin |first8=Kiflom G. |last9=Oelkers |first9=Eric H. |last10=Gislason |first10=Sigurður R. |date=2019-04-30 |title=Rapid CO2 mineralisation into calcite at the CarbFix storage site quantified using calcium isotopes |journal=Nature Communications |language=en |volume=10 |issue=1 |pages=1983 |doi=10.1038/s41467-019-10003-8 |pmid=31040283 |pmc=6491611 |issn=2041-1723}} and understanding ocean acidification,{{Cite journal |last1=Fantle |first1=Matthew S. |last2=Ridgwell |first2=Andy |date=2020-08-05 |title=Towards an understanding of the Ca isotopic signal related to ocean acidification and alkalinity overshoots in the rock record |url=https://www.sciencedirect.com/science/article/abs/pii/S0009254120302114 |journal=Chemical Geology |volume=547 |pages=119672 |doi=10.1016/j.chemgeo.2020.119672 |issn=0009-2541}} exploring both ubiquitous and rare magmatic processes, such as formation of granites{{Cite journal |last1=Antonelli |first1=Michael A. |last2=Yakymchuk |first2=Chris |last3=Schauble |first3=Edwin A. |last4=Foden |first4=John |last5=Janoušek |first5=Vojtěch |last6=Moyen |first6=Jean-François |last7=Hoffmann |first7=Jan |last8=Moynier |first8=Frédéric |last9=Bachmann |first9=Olivier |date=2023-04-15 |title=Granite petrogenesis and the δ44Ca of continental crust |url=https://www.sciencedirect.com/science/article/pii/S0012821X23000936 |journal=Earth and Planetary Science Letters |volume=608 |pages=118080 |doi=10.1016/j.epsl.2023.118080 |issn=0012-821X|hdl=20.500.11850/603069 |hdl-access=free }} and carbonatites,{{Cite web |last=admin |title=Calcium isotope fractionation during melt immiscibility and carbonatite petrogenesis {{!}} Geochemical Perspectives Letters |url=https://www.geochemicalperspectivesletters.org/article2338/ |access-date=2024-10-16 |language=en-US}} tracing modern and ancient trophic webs including in dinosaurs,{{Cite journal |last1=Skulan |first1=Joseph |last2=DePaolo |first2=Donald J. |last3=Owens |first3=Thomas L. |date=1997-06-01 |title=Biological control of calcium isotopic abundances in the global calcium cycle |url=https://www.sciencedirect.com/science/article/abs/pii/S0016703797000471 |journal=Geochimica et Cosmochimica Acta |volume=61 |issue=12 |pages=2505–2510 |doi=10.1016/S0016-7037(97)00047-1 |issn=0016-7037}}{{Cite web |last=admin |title=Calcium stable isotopes place Devonian conodonts as first level consumers {{!}} Geochemical Perspectives Letters |url=https://www.geochemicalperspectivesletters.org/article1912/ |access-date=2024-10-16 |language=en-US}}{{Cite journal |last1=Hassler |first1=A. |last2=Martin |first2=J. E. |last3=Amiot |first3=R. |last4=Tacail |first4=T. |last5=Godet |first5=F. Arnaud |last6=Allain |first6=R. |last7=Balter |first7=V. |date=2018-04-11 |title=Calcium isotopes offer clues on resource partitioning among Cretaceous predatory dinosaurs |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=285 |issue=1876 |pages=20180197 |doi=10.1098/rspb.2018.0197 |issn=0962-8452 |pmc=5904318 |pmid=29643213}} assessing weaning practices in ancient humans,{{Cite journal |last1=Tacail |first1=Théo |last2=Thivichon-Prince |first2=Béatrice |last3=Martin |first3=Jeremy E. |last4=Charles |first4=Cyril |last5=Viriot |first5=Laurent |last6=Balter |first6=Vincent |date=2017-06-13 |title=Assessing human weaning practices with calcium isotopes in tooth enamel |journal=Proceedings of the National Academy of Sciences |language=en |volume=114 |issue=24 |pages=6268–6273 |doi=10.1073/pnas.1704412114 |doi-access=free |issn=0027-8424 |pmc=5474782 |pmid=28559355}} and a plethora of other emerging applications.

List of isotopes

{{Isotopes table

|symbol=Ca

|refs=NUBASE2020, AME2020 II

|notes=mass#, unc(), var[], spin(), spin#, hl-nst, daughter-st, EC, n, p

}}

|-id=Calcium-35

| rowspan=3|{{sup|35}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 15

| rowspan=3|35.00557(22)#

| rowspan=3|25.7(2) ms

| Beta decay, p (95.8%)

| {{sup|34}}Ar

| rowspan=3|1/2+#

| rowspan=3|

| β{{sup|+}}, 2p (4.2%)

| {{sup|33}}Cl

| β{{sup|+}} (rare)

| {{sup|35}}K

|-id=Calcium-36

| rowspan=2|{{sup|36}}Ca

| rowspan=2 style="text-align:right" | 20

| rowspan=2 style="text-align:right" | 16

| rowspan=2|35.993074(43)

| rowspan=2|100.9(13) ms

| β{{sup|+}}, p (51.2%)

| {{sup|35}}Ar

| rowspan=2|0+

| rowspan=2|

| β{{sup|+}} (48.8%)

| {{sup|36}}K

|-id=Calcium-37

| rowspan=2|{{sup|37}}Ca

| rowspan=2 style="text-align:right" | 20

| rowspan=2 style="text-align:right" | 17

| rowspan=2|36.98589785(68)

| rowspan=2|181.0(9) ms

| β{{sup|+}}, p (76.8%)

| {{sup|36}}Ar

| rowspan=2|3/2+

| rowspan=2|

| β{{sup|+}} (23.2%)

| {{sup|37}}K

|-id=Calcium-38

| {{sup|38}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 18

| 37.97631922(21)

| 443.70(25) ms

| β{{sup|+}}

| {{sup|38}}K

| 0+

|-id=Calcium-39

| {{sup|39}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 19

| 38.97071081(64)

| 860.3(8) ms

| β{{sup|+}}

| {{sup|39}}K

| 3/2+

|-id=Calcium-40

| {{sup|40}}CaHeaviest observationally stable nuclide with equal numbers of protons and neutrons

| style="text-align:right" | 20

| 39.962590850(22)

| colspan=3 align=center|Observationally stableBelieved to undergo double electron capture to {{sup|40}}Ar with a half-life no less than 9.9×10{{sup|21}} y

| 0+

| 0.9694(16)

| 0.96933–0.96947

|-id=Calcium-41

| {{sup|41}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 21

| 40.96227791(15)

| 9.94(15)×10{{sup|4}} y

| EC

| {{sup|41}}K

| 7/2−

| TraceCosmogenic nuclide

|-id=Calcium-42

| {{sup|42}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 22

| 41.95861778(16)

| colspan=3 align=center|Stable

| 0+

| 0.00647(23)

| 0.00646–0.00648

|-id=Calcium-43

| {{sup|43}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 23

| 42.95876638(24)

| colspan=3 align=center|Stable

| 7/2−

| 0.00135(10)

| 0.00135–0.00135

|-id=Calcium-44

| {{sup|44}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 24

| 43.95548149(35)

| colspan=3 align=center|Stable

| 0+

| 0.0209(11)

| 0.02082–0.02092

|-id=Calcium-45

| {{sup|45}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 25

| 44.95618627(39)

| 162.61(9) d

| β{{sup|−}}

| {{sup|45}}Sc

| 7/2−

|-id=Calcium-46

| {{sup|46}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 26

| 45.9536877(24)

| colspan=3 align=center|Observationally stableBelieved to undergo β{{sup|−}}β{{sup|−}} decay to {{sup|46}}Ti

| 0+

| 4×10{{sup|−5}}

| 4×10{{sup|−5}}–4×10{{sup|−5}}

|-id=Calcium-47

| {{sup|47}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 27

| 46.9545411(24)

| 4.536(3) d

| β{{sup|−}}

| {{sup|47}}Sc

| 7/2−

| Calcium-48Primordial radionuclideBelieved to be capable of undergoing triple beta decay with very long partial half-life

| style="text-align:right" | 20

| style="text-align:right" | 28

| 47.952522654(18)

| 5.6(10)×10{{sup|19}} y|| β{{sup|−}}β{{sup|−}}Lightest nuclide known to undergo double beta decay{{refn|group="n"|Theorized to also undergo β{{sup|−}} decay to {{sup|48}}Sc with a partial half-life exceeding 1.1{{su|p=+0.8|b=−0.6}}×10{{sup|21}} years{{cite journal |last1=Aunola |first1=M. |last2=Suhonen |first2=J. |last3=Siiskonen |first3=T. |title=Shell-model study of the highly forbidden beta decay {{sup|48}}Ca → {{sup|48}}Sc |date=1999 |journal=EPL |volume=46 |issue=5 |page=577 |doi=10.1209/epl/i1999-00301-2|bibcode=1999EL.....46..577A |s2cid=250836275 }}}}

| {{sup|48}}Ti

| 0+

| 0.00187(21)

| 0.00186–0.00188

|-id=Calcium-49

| {{sup|49}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 29

| 48.95566263(19)

| 8.718(6) min

| β{{sup|−}}

| {{sup|49}}Sc

| 3/2−

|-id=Calcium-50

| {{sup|50}}Ca

| style="text-align:right" | 20

| style="text-align:right" | 30

| 49.9574992(17)

| 13.45(5) s

| β{{sup|−}}

| {{sup|50}}Sc

| 0+

|-id=Calcium-51

| rowspan=2|{{sup|51}}Ca

| rowspan=2 style="text-align:right" | 20

| rowspan=2 style="text-align:right" | 31

| rowspan=2|50.96099566(56)

| rowspan=2|10.0(8) s

| β{{sup|−}}

| {{sup|51}}Sc

| rowspan=2|3/2−

| rowspan=2|

| β{{sup|−}}, n?

| {{sup|50}}Sc

|-id=Calcium-52

| rowspan=2|{{sup|52}}Ca

| rowspan=2 style="text-align:right" | 20

| rowspan=2 style="text-align:right" | 32

| rowspan=2|51.96321365(72)

| rowspan=2|4.6(3) s

| β{{sup|−}} (>98%)

| {{sup|52}}Sc

| rowspan=2|0+

| rowspan=2|

| β{{sup|−}}, n (<2%)

| {{sup|51}}Sc

|-id=Calcium-53

| rowspan=2|{{sup|53}}Ca

| rowspan=2 style="text-align:right" | 20

| rowspan=2 style="text-align:right" | 33

| rowspan=2|52.968451(47)

| rowspan=2|461(90) ms

| β{{sup|−}} (60%)

| {{sup|53}}Sc

| rowspan=2|1/2−#

| rowspan=2|

| β{{sup|−}}, n (40%)

| {{sup|52}}Sc

|-id=Calcium-54

| rowspan=3|{{sup|54}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 34

| rowspan=3|53.972989(52)

| rowspan=3|90(6) ms

| β{{sup|−}}

| {{sup|54}}Sc

| rowspan=3|0+

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|53}}Sc

| β{{sup|−}}, 2n?

| {{sup|52}}Sc

|-id=Calcium-55

| rowspan=3|{{sup|55}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 35

| rowspan=3|54.97998(17)

| rowspan=3|22(2) ms

| β{{sup|−}}

| {{sup|55}}Sc

| rowspan=3|5/2−#

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|54}}Sc

| β{{sup|−}}, 2n?

| {{sup|53}}Sc

|-id=Calcium-56

| rowspan=3|{{sup|56}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 36

| rowspan=3|55.98550(27)

| rowspan=3|11(2) ms

| β{{sup|−}}

| {{sup|56}}Sc

| rowspan=3|0+

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|55}}Sc

| β{{sup|−}}, 2n?

| {{sup|54}}Sc

|-id=Calcium-57

| rowspan=3|{{sup|57}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 37

| rowspan=3|56.99296(43)#

| rowspan=3|8# ms [>620 ns]

| β{{sup|−}}?

| {{sup|57}}Sc

| rowspan=3|5/2−#

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|56}}Sc

| β{{sup|−}}, 2n?

| {{sup|55}}Sc

|-id=Calcium-58

| rowspan=3|{{sup|58}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 38

| rowspan=3|57.99836(54)#

| rowspan=3|4# ms [>620 ns]

| β{{sup|−}}?

| {{sup|58}}Sc

| rowspan=3|0+

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|57}}Sc

| β{{sup|−}}, 2n?

| {{sup|56}}Sc

|-id=Calcium-59

| rowspan=3|{{sup|59}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 39

| rowspan=3|59.00624(64)#

| rowspan=3|5# ms [>400 ns]

| β{{sup|−}}?

| {{sup|59}}Sc

| rowspan=3|5/2−#

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|58}}Sc

| β{{sup|−}}, 2n?

| {{sup|57}}Sc

| rowspan=3|{{sup|60}}Ca

| rowspan=3 style="text-align:right" | 20

| rowspan=3 style="text-align:right" | 40

| rowspan=3|60.01181(75)#

| rowspan=3|2# ms [>400 ns]

| β{{sup|−}}?

| {{sup|60}}Sc

| rowspan=3|0+

| rowspan=3|

| β{{sup|−}}, n?

| {{sup|59}}Sc

| β{{sup|−}}, 2n?

| {{sup|58}}Sc

Calcium-48

File:Calcium-48 carbonate.png

Calcium-48 is a doubly magic nucleus with 28 neutrons; unusually neutron-rich for a light primordial nucleus. It decays via double beta decay with an extremely long half-life of about 6.4×10{{sup|19}} years, though single beta decay is also theoretically possible.{{Cite journal

|last1=Arnold |first1=R.

|display-authors=etal

|year=2016

|collaboration=NEMO-3 Collaboration

|title= Measurement of the double-beta decay half-life and search for the neutrinoless double-beta decay of {{sup|48}}Ca with the NEMO-3 detector

|journal=Physical Review D

|volume=93 |issue=11

|pages=112008

|doi= 10.1103/PhysRevD.93.112008

|arxiv=1604.01710|bibcode=2016PhRvD..93k2008A}} This decay can analyzed with the sd nuclear shell model, and it is more energetic (4.27 MeV) than any other double beta decay.{{cite journal | last = Balysh | first = A. | year = 1996 | title = Double Beta Decay of {{sup|48}}Ca | journal = Physical Review Letters | volume = 77 | pages = 5186–5189 | doi = 10.1103/PhysRevLett.77.5186 | pmid = 10062737 | issue = 26 | bibcode=1996PhRvL..77.5186B|arxiv = nucl-ex/9608001 |display-authors=etal}} It can also be used as a precursor for neutron-rich and superheavy nuclei.{{cite journal | last = Notani | first = M. | year = 2002 | title = New neutron-rich isotopes, {{sup|34}}Ne, {{sup|37}}Na and {{sup|43}}Si, produced by fragmentation of a 64A MeV {{sup|48}}Ca beam | journal = Physics Letters B | volume = 542 | issue = 1–2 | pages = 49–54 | doi = 10.1016/S0370-2693(02)02337-7 |bibcode = 2002PhLB..542...49N |display-authors=etal}}{{cite journal | last = Oganessian | first = Yu. Ts. |date=October 2006 | title = Synthesis of the isotopes of elements 118 and 116 in the {{sup|249}}Cf and {{sup|245}}Cm + {{sup|48}}Ca fusion reactions | journal = Physical Review C | volume = 74 | pages = 044602 | doi = 10.1103/PhysRevC.74.044602 | bibcode=2006PhRvC..74d4602O | issue = 4|display-authors=etal| doi-access = free }}

Calcium-60

Calcium-60 is the heaviest known isotope {{as of|2020|lc=y}}. First observed in 2018 at Riken alongside {{sup|59}}Ca and seven isotopes of other elements,{{cite journal |last1=Tarasov |first1=O. B. |last2=Ahn |first2=D. S. |last3=Bazin |first3=D. |last4=Fukuda |first4=N. |last5=Gade |first5=A. |last6=Hausmann |first6=M. |last7=Inabe |first7=N. |last8=Ishikawa |first8=S. |last9=Iwasa |first9=N. |last10=Kawata |first10=K. |last11=Komatsubara |first11=T. |last12=Kubo |first12=T. |last13=Kusaka |first13=K. |last14=Morrissey |first14=D. J. |last15=Ohtake |first15=M. |last16=Otsu |first16=H. |last17=Portillo |first17=M. |last18=Sakakibara |first18=T. |last19=Sakurai |first19=H. |last20=Sato |first20=H. |last21=Sherrill |first21=B. M. |last22=Shimizu |first22=Y. |last23=Stolz |first23=A. |last24=Sumikama |first24=T. |last25=Suzuki |first25=H. |last26=Takeda |first26=H. |last27=Thoennessen |first27=M. |last28=Ueno |first28=H. |last29=Yanagisawa |first29=Y. |last30=Yoshida |first30=K. |title=Discovery of {{sup|60}}Ca and Implications For the Stability of {{sup|70}}Ca |journal=Physical Review Letters |date=11 July 2018 |volume=121 |issue=2 |page=022501 |doi=10.1103/PhysRevLett.121.022501 |display-authors=3|doi-access=free |pmid=30085743 }} its existence suggests that there are additional even-N isotopes of calcium up to at least {{sup|70}}Ca, while {{sup|59}}Ca is probably the last bound isotope with odd N.{{cite journal |last1=Neufcourt |first1=Léo |last2=Cao |first2=Yuchen |last3=Nazarewicz |first3=Witold |last4=Olsen |first4=Erik |last5=Viens |first5=Frederi |title=Neutron Drip Line in the Ca Region from Bayesian Model Averaging |journal=Physical Review Letters |date=14 February 2019 |volume=122 |issue=6 |page=062502 |doi=10.1103/PhysRevLett.122.062502 |pmid=30822058 |arxiv=1901.07632 |display-authors=3}} Earlier predictions had estimated the neutron drip line to occur at {{sup|60}}Ca, with {{sup|59}}Ca unbound.

In the neutron-rich region, N = 40 becomes a magic number, so {{sup|60}}Ca was considered early on to be a possibly doubly magic nucleus, as is observed for the {{sup|68}}Ni isotone.{{cite journal |last1=Gade |first1=A. |last2=Janssens |first2=R. V. F. |last3=Weisshaar |first3=D. |last4=Brown |first4=B. A. |last5=Lunderberg |first5=E. |last6=Albers |first6=M. |last7=Bader |first7=V. M. |last8=Baugher |first8=T. |last9=Bazin |first9=D. |last10=Berryman |first10=J. S. |last11=Campbell |first11=C. M. |last12=Carpenter |first12=M. P. |last13=Chiara |first13=C. J. |last14=Crawford |first14=H. L. |last15=Cromaz |first15=M. |last16=Garg |first16=U. |last17=Hoffman |first17=C. R. |last18=Kondev |first18=F. G. |last19=Langer |first19=C. |last20=Lauritsen |first20=T. |last21=Lee |first21=I. Y. |last22=Lenzi |first22=S. M. |last23=Matta |first23=J. T. |last24=Nowacki |first24=F. |last25=Recchia |first25=F. |last26=Sieja |first26=K. |last27=Stroberg |first27=S. R. |last28=Tostevin |first28=J. A. |last29=Williams |first29=S. J. |last30=Wimmer |first30=K. |last31=Zhu |first31=S. |title=Nuclear Structure Towards N = 40 {{sup|60}}Ca: In-Beam γ -Ray Spectroscopy of {{sup|58, 60}}Ti |journal=Physical Review Letters |date=21 March 2014 |volume=112 |issue=11 |page=112503 |doi=10.1103/PhysRevLett.112.112503 |pmid=24702356 |display-authors=3|arxiv=1402.5944 }}{{cite journal |last1=Cortés |first1=M.L. |last2=Rodriguez |first2=W. |last3=Doornenbal |first3=P. |last4=Obertelli |first4=A. |last5=Holt |first5=J.D. |last6=Lenzi |first6=S.M. |last7=Menéndez |first7=J. |last8=Nowacki |first8=F. |last9=Ogata |first9=K. |last10=Poves |first10=A. |last11=Rodríguez |first11=T.R. |last12=Schwenk |first12=A. |last13=Simonis |first13=J. |last14=Stroberg |first14=S.R. |last15=Yoshida |first15=K. |last16=Achouri |first16=L. |last17=Baba |first17=H. |last18=Browne |first18=F. |last19=Calvet |first19=D. |last20=Château |first20=F. |last21=Chen |first21=S. |last22=Chiga |first22=N. |last23=Corsi |first23=A. |last24=Delbart |first24=A. |last25=Gheller |first25=J.-M. |last26=Giganon |first26=A. |last27=Gillibert |first27=A. |last28=Hilaire |first28=C. |last29=Isobe |first29=T. |last30=Kobayashi |first30=T. |last31=Kubota |first31=Y. |last32=Lapoux |first32=V. |last33=Liu |first33=H.N. |last34=Motobayashi |first34=T. |last35=Murray |first35=I. |last36=Otsu |first36=H. |last37=Panin |first37=V. |last38=Paul |first38=N. |last39=Sakurai |first39=H. |last40=Sasano |first40=M. |last41=Steppenbeck |first41=D. |last42=Stuhl |first42=L. |last43=Sun |first43=Y.L. |last44=Togano |first44=Y. |last45=Uesaka |first45=T. |last46=Wimmer |first46=K. |last47=Yoneda |first47=K. |last48=Aktas |first48=O. |last49=Aumann |first49=T. |last50=Chung |first50=L.X. |last51=Flavigny |first51=F. |last52=Franchoo |first52=S. |last53=Gašparić |first53=I. |last54=Gerst |first54=R.-B. |last55=Gibelin |first55=J. |last56=Hahn |first56=K.I. |last57=Kim |first57=D. |last58=Koiwai |first58=T. |last59=Kondo |first59=Y. |last60=Koseoglou |first60=P. |last61=Lee |first61=J. |last62=Lehr |first62=C. |last63=Linh |first63=B.D. |last64=Lokotko |first64=T. |last65=MacCormick |first65=M. |last66=Moschner |first66=K. |last67=Nakamura |first67=T. |last68=Park |first68=S.Y. |last69=Rossi |first69=D. |last70=Sahin |first70=E. |last71=Sohler |first71=D. |last72=Söderström |first72=P.-A. |last73=Takeuchi |first73=S. |last74=Toernqvist |first74=H. |last75=Vaquero |first75=V. |last76=Wagner |first76=V. |last77=Wang |first77=S. |last78=Werner |first78=V. |last79=Xu |first79=X. |last80=Yamada |first80=H. |last81=Yan |first81=D. |last82=Yang |first82=Z. |last83=Yasuda |first83=M. |last84=Zanetti |first84=L. |title=Shell evolution of N = 40 isotones towards {{sup|60}}Ca: First spectroscopy of {{sup|62}}Ti |journal=Physics Letters B |date=January 2020 |volume=800 |pages=135071 |doi=10.1016/j.physletb.2019.135071 |display-authors=3|doi-access=free |arxiv=1912.07887 }} However, subsequent spectroscopic measurements of the nearby nuclides {{sup|56}}Ca, {{sup|58}}Ca, and {{sup|62}}Ti instead predict that it should lie on the island of inversion known to exist around {{sup|64}}Cr.{{cite journal |last1=Chen |first1=S. |last2=Browne |first2=F. |last3=Doornenbal |first3=P. |last4=Lee |first4=J. |last5=Obertelli |first5=A. |last6=Tsunoda |first6=Y. |last7=Otsuka |first7=T. |last8=Chazono |first8=Y. |last9=Hagen |first9=G. |last10=Holt |first10=J.D. |last11=Jansen |first11=G.R. |last12=Ogata |first12=K. |last13=Shimizu |first13=N. |last14=Utsuno |first14=Y. |last15=Yoshida |first15=K. |last16=Achouri |first16=N.L. |last17=Baba |first17=H. |last18=Calvet |first18=D. |last19=Château |first19=F. |last20=Chiga |first20=N. |last21=Corsi |first21=A. |last22=Cortés |first22=M.L. |last23=Delbart |first23=A. |last24=Gheller |first24=J.-M. |last25=Giganon |first25=A. |last26=Gillibert |first26=A. |last27=Hilaire |first27=C. |last28=Isobe |first28=T. |last29=Kobayashi |first29=T. |last30=Kubota |first30=Y. |last31=Lapoux |first31=V. |last32=Liu |first32=H.N. |last33=Motobayashi |first33=T. |last34=Murray |first34=I. |last35=Otsu |first35=H. |last36=Panin |first36=V. |last37=Paul |first37=N. |last38=Rodriguez |first38=W. |last39=Sakurai |first39=H. |last40=Sasano |first40=M. |last41=Steppenbeck |first41=D. |last42=Stuhl |first42=L. |last43=Sun |first43=Y.L. |last44=Togano |first44=Y. |last45=Uesaka |first45=T. |last46=Wimmer |first46=K. |last47=Yoneda |first47=K. |last48=Aktas |first48=O. |last49=Aumann |first49=T. |last50=Chung |first50=L.X. |last51=Flavigny |first51=F. |last52=Franchoo |first52=S. |last53=Gasparic |first53=I. |last54=Gerst |first54=R.-B. |last55=Gibelin |first55=J. |last56=Hahn |first56=K.I. |last57=Kim |first57=D. |last58=Koiwai |first58=T. |last59=Kondo |first59=Y. |last60=Koseoglou |first60=P. |last61=Lehr |first61=C. |last62=Linh |first62=B.D. |last63=Lokotko |first63=T. |last64=MacCormick |first64=M. |last65=Moschner |first65=K. |last66=Nakamura |first66=T. |last67=Park |first67=S.Y. |last68=Rossi |first68=D. |last69=Sahin |first69=E. |last70=Söderström |first70=P.-A. |last71=Sohler |first71=D. |last72=Takeuchi |first72=S. |last73=Törnqvist |first73=H. |last74=Vaquero |first74=V. |last75=Wagner |first75=V. |last76=Wang |first76=S. |last77=Werner |first77=V. |last78=Xu |first78=X. |last79=Yamada |first79=H. |last80=Yan |first80=D. |last81=Yang |first81=Z. |last82=Yasuda |first82=M. |last83=Zanetti |first83=L. |title=Level structures of {{sup|56, 58}}Ca cast doubt on a doubly magic {{sup|60}}Ca |journal=Physics Letters B |date=August 2023 |volume=843 |pages=138025 |doi=10.1016/j.physletb.2023.138025 |display-authors=3|doi-access=free |arxiv=2307.07077 }}

References

External links

[https://ww.isotopes.gov National Isotope Development Center Official website]{{Dead link|date=February 2023 |bot=InternetArchiveBot |fix-attempted=yes }}
[https://web.archive.org/web/20120506025523/http://ie.lbl.gov/education/parent/Ca_iso.htm Calcium isotopes data from The Berkeley Laboratory Isotopes Project's]

Category:Calcium

Calcium

Isotopes of calcium#Calcium-52

List of isotopes

Calcium-48

Calcium-60

References

Further reading

External links