Isotopes of californium: Difference between revisions
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{{Short description| |
{{Short description|none}} |
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{{Infobox californium isotopes}} |
{{Infobox californium isotopes}} |
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[[Californium]] ( |
[[Californium]] ({{sub|98}}Cf) is an [[artificial element]], and thus a [[standard atomic weight]] cannot be given. Like all artificial elements, it has no [[stable isotope]]s. The first [[isotope]] to be synthesized was {{sup|245}}Cf in 1950. There are 20 known [[radioisotope]]s ranging from {{sup|237}}Cf to {{sup|256}}Cf and one [[nuclear isomer]], {{sup|249m}}Cf. The longest-lived isotope is {{sup|251}}Cf with a [[half-life]] of 898 years. |
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== List of isotopes == |
== List of isotopes == |
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{{Isotopes table |
{{Isotopes table |
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|symbol=Cf |
|symbol=Cf |
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|refs=NUBASE2020 |
|refs=NUBASE2020, AME2020 II |
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|notes=m, unc(), mass#, spin(), spin#, SF, EC |
|notes=m, unc(), mass#, spin(), spin#, SF, EC |
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}} |
}} |
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|-id=Californium-237 |
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|- |
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| rowspan=3| |
| rowspan=3|{{sup|237}}Cf |
||
| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
||
| rowspan=3 style="text-align:right" | 139 |
| rowspan=3 style="text-align:right" | 139 |
||
| rowspan=3|237.06220(10) |
| rowspan=3|237.06220(10) |
||
| rowspan=3|0.8(2) |
| rowspan=3|0.8(2) s |
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| [[alpha decay|α]] (70%) |
| [[alpha decay|α]] (70%) |
||
| |
| {{sup|233}}Cm |
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| rowspan=3|5/2+# |
| rowspan=3|5/2+# |
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|- |
|- |
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| (various) |
| (various) |
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|- |
|- |
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| [[beta decay|β |
| [[beta decay|β{{sup|+}}]] (rare) |
||
| |
| {{sup|237}}Bk |
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|-id=Californium-238 |
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|- |
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| rowspan=2| |
| rowspan=2|{{sup|238}}Cf |
||
| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
||
| rowspan=2 style="text-align:right" | 140 |
| rowspan=2 style="text-align:right" | 140 |
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| rowspan=2|238.06149(32)# |
| rowspan=2|238.06149(32)# |
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| rowspan=2|21.1(13) |
| rowspan=2|21.1(13) ms |
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| SF<ref group="n">Lightest nuclide known to undergo [[spontaneous fission]] as |
| SF<ref group="n">Lightest nuclide known to undergo [[spontaneous fission]] as its main decay mode</ref> |
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| (various) |
| (various) |
||
| rowspan=2|0+ |
| rowspan=2|0+ |
||
|- |
|- |
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| α (<5%) |
| α (<5%) |
||
| |
| {{sup|234}}Cm |
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|-id=Californium-239 |
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|- |
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| rowspan=2| |
| rowspan=2|{{sup|239}}Cf<ref name="239Cf">{{cite journal |last1=Khuyagbaatar |first1=J. |last2=Heßberger |first2=F. P. |last3=Hofmann |first3=S. |last4=Ackermann |first4=D. |last5=Burkhard |first5=H. G. |last6=Heinz |first6=S. |last7=Kindler |first7=B. |last8=Kojouharov |first8=I. |last9=Lommel |first9=B. |last10=Mann |first10=R. |last11=Maurer |first11=J. |last12=Nishio |first12=K. |title=α decay of Fm 243 143 and Fm 245 145 , and of their daughter nuclei |journal=Physical Review C |date=12 October 2020 |volume=102 |issue=4 |page=044312 |doi=10.1103/PhysRevC.102.044312 |s2cid=241259726 |url=https://journals.aps.org/prc/pdf/10.1103/PhysRevC.102.044312 |access-date=24 June 2023 |language=en |issn=2469-9985}}</ref> |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
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| rowspan=2 style="text-align:right" | 141 |
| rowspan=2 style="text-align:right" | 141 |
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| rowspan=2|239.06248(13)# |
| rowspan=2|239.06248(13)# |
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| rowspan=2|28(2) |
| rowspan=2|28(2) s |
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| α (65%) |
| α (65%) |
||
| |
| {{sup|235}}Cm |
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| rowspan=2|(5/2+) |
| rowspan=2|(5/2+) |
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|- |
|- |
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| [[Beta decay|β |
| [[Beta decay|β{{sup|+}}]] (35%) |
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| |
| {{sup|239}}Bk |
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|-id=Californium-240 |
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|- |
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| rowspan=3| |
| rowspan=3|{{sup|240}}Cf |
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| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
||
| rowspan=3 style="text-align:right" | 142 |
| rowspan=3 style="text-align:right" | 142 |
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| rowspan=3|240.062253(19) |
| rowspan=3|240.062253(19) |
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| rowspan=3|40.3(9) |
| rowspan=3|40.3(9) s |
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| α (98.5%) |
| α (98.5%) |
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| |
| {{sup|236}}Cm |
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| rowspan=3|0+ |
| rowspan=3|0+ |
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|- |
|- |
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Line 63: | Line 63: | ||
| (various) |
| (various) |
||
|- |
|- |
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| β |
| β{{sup|+}}? |
||
| |
| {{sup|240}}Bk |
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|-id=Californium-241 |
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|- |
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| rowspan=2| |
| rowspan=2|{{sup|241}}Cf<ref name="239Cf"/> |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
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| rowspan=2 style="text-align:right" | 143 |
| rowspan=2 style="text-align:right" | 143 |
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| rowspan=2|241.06369(18)# |
| rowspan=2|241.06369(18)# |
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| rowspan=2|2.35(18) |
| rowspan=2|2.35(18) min |
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| β |
| β{{sup|+}} (85%) |
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| |
| {{sup|241}}Bk |
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| rowspan=2|(7/2−) |
| rowspan=2|(7/2−) |
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|- |
|- |
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| α (15%) |
| α (15%) |
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| |
| {{sup|237}}Cm |
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|-id=Californium-242 |
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|- |
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| rowspan=3| |
| rowspan=3|{{sup|242}}Cf |
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| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
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| rowspan=3 style="text-align:right" | 144 |
| rowspan=3 style="text-align:right" | 144 |
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| rowspan=3|242.063755(14) |
| rowspan=3|242.063755(14) |
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| rowspan=3|3.49(15) |
| rowspan=3|3.49(15) min |
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| α (61%) |
| α (61%) |
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| |
| {{sup|238}}Cm |
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| rowspan=3|0+ |
| rowspan=3|0+ |
||
|- |
|- |
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| β |
| β{{sup|+}} (39%) |
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| |
| {{sup|242}}Bk |
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|- |
|- |
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| SF (<0.014%) |
| SF (<0.014%) |
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| (various) |
| (various) |
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|-id=Californium-243 |
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|- |
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| rowspan=2| |
| rowspan=2|{{sup|243}}Cf |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
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| rowspan=2 style="text-align:right" | 145 |
| rowspan=2 style="text-align:right" | 145 |
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| rowspan=2|243.06548(19)# |
| rowspan=2|243.06548(19)# |
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| rowspan=2|10.8(3) |
| rowspan=2|10.8(3) min |
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| β |
| β{{sup|+}} (86%) |
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| |
| {{sup|243}}Bk |
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| rowspan=2|(1/2+) |
| rowspan=2|(1/2+) |
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|- |
|- |
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| α (14%) |
| α (14%) |
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| |
| {{sup|239}}Cm |
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|-id=Californium-244 |
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|- |
|||
| rowspan=2| |
| rowspan=2|{{sup|244}}Cf |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
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| rowspan=2 style="text-align:right" | 146 |
| rowspan=2 style="text-align:right" | 146 |
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| rowspan=2|244.0659994(28) |
| rowspan=2|244.0659994(28) |
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| rowspan=2|19.5(5) |
| rowspan=2|19.5(5) min |
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| α (75%) |
| α (75%) |
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| |
| {{sup|240}}Cm |
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| rowspan=2|0+ |
| rowspan=2|0+ |
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|- |
|- |
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| [[Electron capture|EC]] (25%) |
| [[Electron capture|EC]] (25%) |
||
| |
| {{sup|244}}Bk |
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|-id=Californium-245 |
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|- |
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| rowspan=2| |
| rowspan=2|{{sup|245}}Cf |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
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| rowspan=2 style="text-align:right" | 147 |
| rowspan=2 style="text-align:right" | 147 |
||
| rowspan=2|245.0680468(26) |
| rowspan=2|245.0680468(26) |
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| rowspan=2|45.0(15) |
| rowspan=2|45.0(15) min |
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| β |
| β{{sup|+}} (64.7%) |
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| |
| {{sup|245}}Bk |
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| rowspan=2|1/2+ |
| rowspan=2|1/2+ |
||
|- |
|- |
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| α (35.3%) |
| α (35.3%) |
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| |
| {{sup|241}}Cm |
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|-id=Californium-245m |
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|- |
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| style="text-indent:1em" | |
| style="text-indent:1em" | {{sup|245m}}Cf |
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| colspan="3" style="text-indent:2em" | 57(4) |
| colspan="3" style="text-indent:2em" | 57(4) keV |
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| >100# |
| >100# ns |
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| IT |
| IT |
||
| |
| {{sup|245}}Cf |
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| (7/2+) |
| (7/2+) |
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|-id=Californium-246 |
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|- |
|||
| rowspan=3| |
| rowspan=3|{{sup|246}}Cf |
||
| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
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| rowspan=3 style="text-align:right" | 148 |
| rowspan=3 style="text-align:right" | 148 |
||
| rowspan=3|246.0688037(16) |
| rowspan=3|246.0688037(16) |
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| rowspan=3|35.7(5) |
| rowspan=3|35.7(5) h |
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| α |
| α |
||
| |
| {{sup|242}}Cm |
||
| rowspan=3|0+ |
| rowspan=3|0+ |
||
|- |
|- |
||
| SF (2.4×10 |
| SF (2.4×10{{sup|−4}}%) |
||
| (various) |
| (various) |
||
|- |
|- |
||
| EC? |
| EC? |
||
| |
| {{sup|246}}Bk |
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|-id=Californium-247 |
|||
|- |
|||
| rowspan=2| |
| rowspan=2|{{sup|247}}Cf |
||
| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
||
| rowspan=2 style="text-align:right" | 149 |
| rowspan=2 style="text-align:right" | 149 |
||
| rowspan=2|247.070971(15) |
| rowspan=2|247.070971(15) |
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| rowspan=2|3.11(3) |
| rowspan=2|3.11(3) h |
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| EC (99.965%) |
| EC (99.965%) |
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| |
| {{sup|247}}Bk |
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| rowspan=2|(7/2+) |
| rowspan=2|(7/2+) |
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|- |
|- |
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| α (.035%) |
| α (.035%) |
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| |
| {{sup|243}}Cm |
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|-id=Californium-248 |
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|- |
|||
| rowspan=2| |
| rowspan=2|{{sup|248}}Cf |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
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| rowspan=2 style="text-align:right" | 150 |
| rowspan=2 style="text-align:right" | 150 |
||
| rowspan=2|248.0721829(55) |
| rowspan=2|248.0721829(55) |
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| rowspan=2|333.5(28) |
| rowspan=2|333.5(28) d |
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| α (99.997%) |
| α (99.997%) |
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| |
| {{sup|244}}Cm |
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| rowspan=2|0+ |
| rowspan=2|0+ |
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|- |
|- |
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| SF (.0029%) |
| SF (.0029%) |
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| (various) |
| (various) |
||
|-id=Californium-249 |
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|- |
|||
| rowspan=2| |
| rowspan=2|{{sup|249}}Cf |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
||
| rowspan=2 style="text-align:right" | 151 |
| rowspan=2 style="text-align:right" | 151 |
||
| rowspan=2|249.0748504(13) |
| rowspan=2|249.0748504(13) |
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| rowspan=2|351(2) |
| rowspan=2|351(2) y |
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| α |
| α |
||
| |
| {{sup|245}}Cm |
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| rowspan=2|9/2− |
| rowspan=2|9/2− |
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|- |
|- |
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| SF (5×10 |
| SF (5×10{{sup|−7}}%) |
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| (various) |
| (various) |
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|-id=Californium-249m |
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|- |
|||
| style="text-indent:1em" | |
| style="text-indent:1em" | {{sup|249m}}Cf |
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| colspan="3" style="text-indent:2em" | 144.98(5) |
| colspan="3" style="text-indent:2em" | 144.98(5) keV |
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| 45(5) |
| 45(5) μs |
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| [[Isomeric transition|IT]] |
| [[Isomeric transition|IT]] |
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| |
| {{sup|249}}Cf |
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| 5/2+ |
| 5/2+ |
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|-id=Californium-250 |
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|- |
|||
| rowspan=2| |
| rowspan=2|{{sup|250}}Cf |
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| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
||
| rowspan=2 style="text-align:right" | 152 |
| rowspan=2 style="text-align:right" | 152 |
||
| rowspan=2|250.0764045(17) |
| rowspan=2|250.0764045(17) |
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| rowspan=2|13.08(9) |
| rowspan=2|13.08(9) y |
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| α (99.923%) |
| α (99.923%) |
||
| |
| {{sup|246}}Cm |
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| rowspan=2|0+ |
| rowspan=2|0+ |
||
|- |
|- |
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| SF (.077%) |
| SF (.077%) |
||
| (various) |
| (various) |
||
|-id=Californium-251 |
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|- |
|||
| |
| {{sup|251}}Cf<ref group="n">High [[neutron cross-section]], tends to absorb neutrons</ref> |
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| style="text-align:right" | 98 |
| style="text-align:right" | 98 |
||
| style="text-align:right" | 153 |
| style="text-align:right" | 153 |
||
| 251.0795872(42) |
| 251.0795872(42) |
||
| 898(44) |
| 898(44) y |
||
| α |
| α |
||
| |
| {{sup|247}}Cm |
||
| 1/2+ |
| 1/2+ |
||
|-id=Californium-251m |
|||
|- |
|||
| style="text-indent:1em" | |
| style="text-indent:1em" | {{sup|251m}}Cf |
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| colspan="3" style="text-indent:2em" | 370.47(3) |
| colspan="3" style="text-indent:2em" | 370.47(3) keV |
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| 1.3(1) |
| 1.3(1) μs |
||
| IT |
| IT |
||
| |
| {{sup|251}}Cf |
||
| 11/2− |
| 11/2− |
||
|- |
|- |
||
| rowspan=2| |
| rowspan=2|{{sup|252}}Cf<ref group="n">Most common isotope</ref> |
||
| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
||
| rowspan=2 style="text-align:right" | 154 |
| rowspan=2 style="text-align:right" | 154 |
||
| rowspan=2|252.0816265(25) |
| rowspan=2|252.0816265(25) |
||
| rowspan=2|2.645(8) |
| rowspan=2|2.645(8) y |
||
| α (96.8972%) |
| α (96.8972%) |
||
| |
| {{sup|248}}Cm |
||
| rowspan=2|0+ |
| rowspan=2|0+ |
||
|- |
|- |
||
| SF (3.1028%)<ref group="n">High neutron emitter, average 3.7 [[neutron]]s per [[Nuclear fission|fission]]</ref> |
| SF (3.1028%)<ref group="n">High neutron emitter, average 3.7 [[neutron]]s per [[Nuclear fission|fission]]</ref> |
||
| (various) |
| (various) |
||
|-id=Californium-253 |
|||
|- |
|||
| rowspan=2| |
| rowspan=2|{{sup|253}}Cf |
||
| rowspan=2 style="text-align:right" | 98 |
| rowspan=2 style="text-align:right" | 98 |
||
| rowspan=2 style="text-align:right" | 155 |
| rowspan=2 style="text-align:right" | 155 |
||
| rowspan=2|253.0851337(46) |
| rowspan=2|253.0851337(46) |
||
| rowspan=2|17.81(8) |
| rowspan=2|17.81(8) d |
||
| β |
| β{{sup|−}} (99.69%) |
||
| |
| {{sup|253}}Es |
||
| rowspan=2|(7/2+) |
| rowspan=2|(7/2+) |
||
|- |
|- |
||
| α (.31%) |
| α (.31%) |
||
| |
| {{sup|249}}Cm |
||
|-id=Californium-254 |
|||
|- |
|||
| rowspan=3| |
| rowspan=3|{{sup|254}}Cf |
||
| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
||
| rowspan=3 style="text-align:right" | 156 |
| rowspan=3 style="text-align:right" | 156 |
||
| rowspan=3|254.087324(12) |
| rowspan=3|254.087324(12) |
||
| rowspan=3|60.5(2) |
| rowspan=3|60.5(2) d |
||
| SF (99.69%) |
| SF (99.69%) |
||
| (various) |
| (various) |
||
Line 256: | Line 256: | ||
|- |
|- |
||
| α (.31%) |
| α (.31%) |
||
| |
| {{sup|250}}Cm |
||
|- |
|||
⚫ | |||
⚫ | |||
|- |
|- |
||
⚫ | |||
⚫ | |||
⚫ | |||
|-id=Californium-255 |
|||
⚫ | |||
| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
||
| rowspan=3 style="text-align:right" | 157 |
| rowspan=3 style="text-align:right" | 157 |
||
| rowspan=3|255.09105(22)# |
| rowspan=3|255.09105(22)# |
||
| rowspan=3|85(18) |
| rowspan=3|85(18) min |
||
| β |
| β{{sup|−}} |
||
| |
| {{sup|255}}Es |
||
| rowspan=3|(7/2+) |
| rowspan=3|(7/2+) |
||
|- |
|- |
||
Line 274: | Line 274: | ||
|- |
|- |
||
| α? |
| α? |
||
| |
| {{sup|251}}Cm |
||
|-id=Californium-256 |
|||
|- |
|||
| rowspan=3| |
| rowspan=3|{{sup|256}}Cf |
||
| rowspan=3 style="text-align:right" | 98 |
| rowspan=3 style="text-align:right" | 98 |
||
| rowspan=3 style="text-align:right" | 158 |
| rowspan=3 style="text-align:right" | 158 |
||
| rowspan=3|256.09344(34)# |
| rowspan=3|256.09344(34)# |
||
| rowspan=3|12.3(12) |
| rowspan=3|12.3(12) min |
||
| SF |
| SF |
||
| (various) |
| (various) |
||
Line 286: | Line 286: | ||
|- |
|- |
||
| α? |
| α? |
||
| |
| {{sup|252}}Cm |
||
|- |
|- |
||
| β |
| β{{sup|−}}β{{sup|−}}? |
||
| |
| {{sup|256}}Fm |
||
|- |
|- |
||
{{Isotopes table/footer}} |
{{Isotopes table/footer}} |
||
Line 298: | Line 298: | ||
== Californium-252 == |
== Californium-252 == |
||
[[File:Cf 252 Produktion.png|thumb|production diagram]] |
[[File:Cf 252 Produktion.png|thumb|Californium-252 production diagram]] |
||
Californium-252 (Cf-252, |
Californium-252 (Cf-252, {{sup|252}}Cf) undergoes spontaneous fission with a [[branching ratio]] of 3.09% and is used in small [[neutron source]]s. Fission neutrons have an energy range of 0 to 13 [[electronvolt|MeV]] with a mean value of 2.3 MeV and a most probable value of 1 MeV.<ref name="252Cf-Dicello">{{cite journal|title = Radiation Quality of Californium-252|journal = [[Physics in Medicine and Biology]]|first1 = J. F.|last1 = Dicello |last2=Gross |first2=W. |last3=Kraljevic |first3=U. |year = 1972 |doi= 10.1088/0031-9155/17/3/301 |volume=17 |issue= 3 |pages = 345–355|pmid = 5070445|bibcode = 1972PMB....17..345D | s2cid=250786668 }}</ref> |
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This [[isotope]] produces high neutron emissions and |
This [[isotope]] produces high neutron emissions and has a number of uses in industries such as nuclear energy, medicine, and [[petrochemical]] exploration. |
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=== Nuclear reactors === |
=== Nuclear reactors === |
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Californium-252 neutron sources are most notably used in the start-up of [[nuclear reactor]]s. Once a reactor is filled with [[nuclear fuel]], the stable neutron emission from said source starts the chain reaction. |
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=== Military and defense === |
=== Military and defense === |
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The portable isotopic neutron spectroscopy (PINS) used by [[United States Armed Forces]], the [[National Guard |
The portable isotopic neutron spectroscopy (PINS) used by [[United States Armed Forces]], the [[National Guard (United States)|National Guard]], [[United States Department of Homeland Security|Homeland Security]], and [[U.S. Customs and Border Protection|Customs and Border Protection]], uses {{sup|252}}Cf sources to detect hazardous contents inside [[Shell (projectile)|artillery projectiles]], [[Mortar (weapon)|mortar projectiles]], [[rocket]]s, [[bomb]]s, [[land mine]]s, and [[improvised explosive device]]s (IED).<ref name="252Cf-frontier-cf252">{{Cite web|title = Portable Isotopic Neutron Spectroscopy (PINS) for the Military|url = http://www.frontier-cf252.com/portable-isotopic-neutron-spectroscopy-military.html|website = Frontier Technology Corp.|access-date = 2016-02-24|archive-date = 2018-06-16|archive-url = https://web.archive.org/web/20180616132135/http://www.frontier-cf252.com/portable-isotopic-neutron-spectroscopy-military.html|url-status = dead}}</ref><ref name="252Cf-Martin">{{Cite journal|title = Production, distribution and applications of californium-252 neutron sources|journal = Applied Radiation and Isotopes|date = 2000-11-01|issn = 0969-8043|pmid = 11003521|pages = 785–792|volume = 53|issue = 4–5|first1 = R. C.|last1 = Martin|first2 = J. B.|last2 = Knauer|first3 = P. A.|last3 = Balo|doi=10.1016/s0969-8043(00)00214-1|url = https://digital.library.unt.edu/ark:/67531/metadc623566/}}</ref> |
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=== Oil and petroleum === |
=== Oil and petroleum === |
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In the [[ |
In the [[oil industry]], {{sup|252}}Cf is used to find layers of [[petroleum]] and water in a [[Oil well|well]]. Instrumentation is lowered into the well, which bombards the formation with high energy neutrons to determine [[porosity]], [[Permeability (earth sciences)|permeability]], and [[hydrocarbon]] presence along the length of the [[borehole]].<ref name="252Cf-frontier-cf252b">{{Cite web|title = Californium-252 & Antimony-Beryllium Sources|url = http://www.frontier-cf252.com|website = Frontier Technology Corp.|access-date = 2016-02-24}}</ref> |
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=== Medicine === |
=== Medicine === |
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Californium-252 has also been used in the treatment of serious forms of [[cancer]]. |
Californium-252 has also been used in the treatment of serious forms of [[cancer]]. For certain types of brain and cervical cancer, {{sup|252}}Cf can be used as a more cost-effective substitute for [[radium]].<ref name="252Cf-Maruyama">{{Cite journal|title = Five-year cure of cervical cancer treated using californium-252 neutron brachytherapy|journal = American Journal of Clinical Oncology|date = 1984-10-01|issn = 0277-3732|pmid = 6391143|pages = 487–493|volume = 7|issue = 5|first1 = Y.|last1 = Maruyama|first2 = J. R.|last2 = van Nagell|first3 = J.|last3 = Yoneda|first4 = E.|last4 = Donaldson|first5 = M.|last5 = Hanson|first6 = A.|last6 = Martin|first7 = L. C.|last7 = Wilson|first8 = C. W.|last8 = Coffey|first9 = J.|last9 = Feola|doi=10.1097/00000421-198410000-00018|s2cid = 12553815}}</ref> |
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== References == |
== References == |
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| ref = {{sfnRef|CRC|2006}} |
| ref = {{sfnRef|CRC|2006}} |
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}} |
}} |
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* Isotope masses from: |
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**{{NUBASE 2003}} |
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* Half-life, spin, and isomer data selected from the following sources. |
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**{{NUBASE 2003}} |
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**{{NNDC}} |
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**{{CRC85|chapter=11}} |
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{{Navbox element isotopes}} |
{{Navbox element isotopes}} |
Latest revision as of 23:23, 12 October 2024
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Californium (98Cf) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 245Cf in 1950. There are 20 known radioisotopes ranging from 237Cf to 256Cf and one nuclear isomer, 249mCf. The longest-lived isotope is 251Cf with a half-life of 898 years.
List of isotopes
[edit]Nuclide [n 1] |
Z | N | Isotopic mass (Da)[3] [n 2][n 3] |
Half-life[4] |
Decay mode[4] [n 4] |
Daughter isotope |
Spin and parity[4] [n 5][n 6] | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy | |||||||||||||||||||
237Cf | 98 | 139 | 237.06220(10) | 0.8(2) s | α (70%) | 233Cm | 5/2+# | ||||||||||||
SF (30%) | (various) | ||||||||||||||||||
β+ (rare) | 237Bk | ||||||||||||||||||
238Cf | 98 | 140 | 238.06149(32)# | 21.1(13) ms | SF[n 7] | (various) | 0+ | ||||||||||||
α (<5%) | 234Cm | ||||||||||||||||||
239Cf[5] | 98 | 141 | 239.06248(13)# | 28(2) s | α (65%) | 235Cm | (5/2+) | ||||||||||||
β+ (35%) | 239Bk | ||||||||||||||||||
240Cf | 98 | 142 | 240.062253(19) | 40.3(9) s | α (98.5%) | 236Cm | 0+ | ||||||||||||
SF (1.5%) | (various) | ||||||||||||||||||
β+? | 240Bk | ||||||||||||||||||
241Cf[5] | 98 | 143 | 241.06369(18)# | 2.35(18) min | β+ (85%) | 241Bk | (7/2−) | ||||||||||||
α (15%) | 237Cm | ||||||||||||||||||
242Cf | 98 | 144 | 242.063755(14) | 3.49(15) min | α (61%) | 238Cm | 0+ | ||||||||||||
β+ (39%) | 242Bk | ||||||||||||||||||
SF (<0.014%) | (various) | ||||||||||||||||||
243Cf | 98 | 145 | 243.06548(19)# | 10.8(3) min | β+ (86%) | 243Bk | (1/2+) | ||||||||||||
α (14%) | 239Cm | ||||||||||||||||||
244Cf | 98 | 146 | 244.0659994(28) | 19.5(5) min | α (75%) | 240Cm | 0+ | ||||||||||||
EC (25%) | 244Bk | ||||||||||||||||||
245Cf | 98 | 147 | 245.0680468(26) | 45.0(15) min | β+ (64.7%) | 245Bk | 1/2+ | ||||||||||||
α (35.3%) | 241Cm | ||||||||||||||||||
245mCf | 57(4) keV | >100# ns | IT | 245Cf | (7/2+) | ||||||||||||||
246Cf | 98 | 148 | 246.0688037(16) | 35.7(5) h | α | 242Cm | 0+ | ||||||||||||
SF (2.4×10−4%) | (various) | ||||||||||||||||||
EC? | 246Bk | ||||||||||||||||||
247Cf | 98 | 149 | 247.070971(15) | 3.11(3) h | EC (99.965%) | 247Bk | (7/2+) | ||||||||||||
α (.035%) | 243Cm | ||||||||||||||||||
248Cf | 98 | 150 | 248.0721829(55) | 333.5(28) d | α (99.997%) | 244Cm | 0+ | ||||||||||||
SF (.0029%) | (various) | ||||||||||||||||||
249Cf | 98 | 151 | 249.0748504(13) | 351(2) y | α | 245Cm | 9/2− | ||||||||||||
SF (5×10−7%) | (various) | ||||||||||||||||||
249mCf | 144.98(5) keV | 45(5) μs | IT | 249Cf | 5/2+ | ||||||||||||||
250Cf | 98 | 152 | 250.0764045(17) | 13.08(9) y | α (99.923%) | 246Cm | 0+ | ||||||||||||
SF (.077%) | (various) | ||||||||||||||||||
251Cf[n 8] | 98 | 153 | 251.0795872(42) | 898(44) y | α | 247Cm | 1/2+ | ||||||||||||
251mCf | 370.47(3) keV | 1.3(1) μs | IT | 251Cf | 11/2− | ||||||||||||||
252Cf[n 9] | 98 | 154 | 252.0816265(25) | 2.645(8) y | α (96.8972%) | 248Cm | 0+ | ||||||||||||
SF (3.1028%)[n 10] | (various) | ||||||||||||||||||
253Cf | 98 | 155 | 253.0851337(46) | 17.81(8) d | β− (99.69%) | 253Es | (7/2+) | ||||||||||||
α (.31%) | 249Cm | ||||||||||||||||||
254Cf | 98 | 156 | 254.087324(12) | 60.5(2) d | SF (99.69%) | (various) | 0+ | ||||||||||||
α (.31%) | 250Cm | ||||||||||||||||||
β−β−? | 254Fm | ||||||||||||||||||
255Cf | 98 | 157 | 255.09105(22)# | 85(18) min | β− | 255Es | (7/2+) | ||||||||||||
SF? | (various) | ||||||||||||||||||
α? | 251Cm | ||||||||||||||||||
256Cf | 98 | 158 | 256.09344(34)# | 12.3(12) min | SF | (various) | 0+ | ||||||||||||
α? | 252Cm | ||||||||||||||||||
β−β−? | 256Fm | ||||||||||||||||||
This table header & footer: |
- ^ mCf – Excited nuclear isomer.
- ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ^
Modes of decay:
EC: Electron capture SF: Spontaneous fission - ^ ( ) spin value – Indicates spin with weak assignment arguments.
- ^ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ^ Lightest nuclide known to undergo spontaneous fission as its main decay mode
- ^ High neutron cross-section, tends to absorb neutrons
- ^ Most common isotope
- ^ High neutron emitter, average 3.7 neutrons per fission
Actinides vs fission products
[edit]Actinides[6] by decay chain | Half-life range (a) |
Fission products of 235U by yield[7] | ||||||
---|---|---|---|---|---|---|---|---|
4n | 4n + 1 | 4n + 2 | 4n + 3 | 4.5–7% | 0.04–1.25% | <0.001% | ||
228Ra№ | 4–6 a | 155Euþ | ||||||
248Bk[8] | > 9 a | |||||||
244Cmƒ | 241Puƒ | 250Cf | 227Ac№ | 10–29 a | 90Sr | 85Kr | 113mCdþ | |
232Uƒ | 238Puƒ | 243Cmƒ | 29–97 a | 137Cs | 151Smþ | 121mSn | ||
249Cfƒ | 242mAmƒ | 141–351 a |
No fission products have a half-life | |||||
241Amƒ | 251Cfƒ[9] | 430–900 a | ||||||
226Ra№ | 247Bk | 1.3–1.6 ka | ||||||
240Pu | 229Th | 246Cmƒ | 243Amƒ | 4.7–7.4 ka | ||||
245Cmƒ | 250Cm | 8.3–8.5 ka | ||||||
239Puƒ | 24.1 ka | |||||||
230Th№ | 231Pa№ | 32–76 ka | ||||||
236Npƒ | 233Uƒ | 234U№ | 150–250 ka | 99Tc₡ | 126Sn | |||
248Cm | 242Pu | 327–375 ka | 79Se₡ | |||||
1.33 Ma | 135Cs₡ | |||||||
237Npƒ | 1.61–6.5 Ma | 93Zr | 107Pd | |||||
236U | 247Cmƒ | 15–24 Ma | 129I₡ | |||||
244Pu | 80 Ma |
... nor beyond 15.7 Ma[10] | ||||||
232Th№ | 238U№ | 235Uƒ№ | 0.7–14.1 Ga | |||||
|
Californium-252
[edit]Californium-252 (Cf-252, 252Cf) undergoes spontaneous fission with a branching ratio of 3.09% and is used in small neutron sources. Fission neutrons have an energy range of 0 to 13 MeV with a mean value of 2.3 MeV and a most probable value of 1 MeV.[11]
This isotope produces high neutron emissions and has a number of uses in industries such as nuclear energy, medicine, and petrochemical exploration.
Nuclear reactors
[edit]Californium-252 neutron sources are most notably used in the start-up of nuclear reactors. Once a reactor is filled with nuclear fuel, the stable neutron emission from said source starts the chain reaction.
Military and defense
[edit]The portable isotopic neutron spectroscopy (PINS) used by United States Armed Forces, the National Guard, Homeland Security, and Customs and Border Protection, uses 252Cf sources to detect hazardous contents inside artillery projectiles, mortar projectiles, rockets, bombs, land mines, and improvised explosive devices (IED).[12][13]
Oil and petroleum
[edit]In the oil industry, 252Cf is used to find layers of petroleum and water in a well. Instrumentation is lowered into the well, which bombards the formation with high energy neutrons to determine porosity, permeability, and hydrocarbon presence along the length of the borehole.[14]
Medicine
[edit]Californium-252 has also been used in the treatment of serious forms of cancer. For certain types of brain and cervical cancer, 252Cf can be used as a more cost-effective substitute for radium.[15]
References
[edit]- ^ CRC 2006, p. 11.196.
- ^ Sonzogni, Alejandro A. (Database Manager), ed. (2008). "Chart of Nuclides". National Nuclear Data Center, Brookhaven National Laboratory. Retrieved 1 March 2010.
- ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
- ^ a b c Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
- ^ a b Khuyagbaatar, J.; Heßberger, F. P.; Hofmann, S.; Ackermann, D.; Burkhard, H. G.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Maurer, J.; Nishio, K. (12 October 2020). "α decay of Fm 243 143 and Fm 245 145 , and of their daughter nuclei". Physical Review C. 102 (4): 044312. doi:10.1103/PhysRevC.102.044312. ISSN 2469-9985. S2CID 241259726. Retrieved 24 June 2023.
- ^ Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
- ^ Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor.
- ^ 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 constant abundance in three samples analysed over a period of about 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 can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]." - ^ This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".
- ^ Excluding those "classically stable" nuclides with half-lives significantly in excess of 232Th; e.g., while 113mCd has a half-life of only fourteen years, that of 113Cd is eight quadrillion years.
- ^ Dicello, J. F.; Gross, W.; Kraljevic, U. (1972). "Radiation Quality of Californium-252". Physics in Medicine and Biology. 17 (3): 345–355. Bibcode:1972PMB....17..345D. doi:10.1088/0031-9155/17/3/301. PMID 5070445. S2CID 250786668.
- ^ "Portable Isotopic Neutron Spectroscopy (PINS) for the Military". Frontier Technology Corp. Archived from the original on 2018-06-16. Retrieved 2016-02-24.
- ^ Martin, R. C.; Knauer, J. B.; Balo, P. A. (2000-11-01). "Production, distribution and applications of californium-252 neutron sources". Applied Radiation and Isotopes. 53 (4–5): 785–792. doi:10.1016/s0969-8043(00)00214-1. ISSN 0969-8043. PMID 11003521.
- ^ "Californium-252 & Antimony-Beryllium Sources". Frontier Technology Corp. Retrieved 2016-02-24.
- ^ Maruyama, Y.; van Nagell, J. R.; Yoneda, J.; Donaldson, E.; Hanson, M.; Martin, A.; Wilson, L. C.; Coffey, C. W.; Feola, J. (1984-10-01). "Five-year cure of cervical cancer treated using californium-252 neutron brachytherapy". American Journal of Clinical Oncology. 7 (5): 487–493. doi:10.1097/00000421-198410000-00018. ISSN 0277-3732. PMID 6391143. S2CID 12553815.
Sources
[edit]- Lide, David R., ed. (2006). Handbook of Chemistry and Physics (87th ed.). CRC Press, Taylor & Francis Group. ISBN 978-0-8493-0487-3.