Isotopes of californium#Californium-256

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 isotopes. The first isotope to be synthesized was {{sup|245}}Cf in 1950. There are 20 known radioisotopes 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.

List of isotopes

File:Cf-249.png

File:Cf-251.png

{{Isotopes table

|symbol=Cf

|refs=NUBASE2020, AME2020 II

|notes=m, unc(), mass#, spin(), spin#, SF, EC

}}

|-id=Californium-237

| rowspan=3|{{sup|237}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 139

| rowspan=3|237.06220(10)

| rowspan=3|0.8(2) s

| α (70%)

| {{sup|233}}Cm

| rowspan=3|5/2+#

| SF (30%)

| (various)

| beta decay (rare)

| {{sup|237}}Bk

|-id=Californium-238

| rowspan=2|{{sup|238}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 140

| rowspan=2|238.06149(32)#

| rowspan=2|21.1(13) ms

| SFLightest nuclide known to undergo spontaneous fission as its main decay mode

| (various)

| rowspan=2|0+

| α (<5%)

| {{sup|234}}Cm

|-id=Californium-239

| rowspan=2|{{sup|239}}Cf{{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|url-access=subscription }}

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 141

| rowspan=2|239.06248(13)#

| rowspan=2|28(2) s

| α (65%)

| {{sup|235}}Cm

| rowspan=2|(5/2+)

| Beta decay (35%)

| {{sup|239}}Bk

|-id=Californium-240

| rowspan=3|{{sup|240}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 142

| rowspan=3|240.062253(19)

| rowspan=3|40.3(9) s

| α (98.5%)

| {{sup|236}}Cm

| rowspan=3|0+

| SF (1.5%)

| (various)

| β{{sup|+}}?

| {{sup|240}}Bk

|-id=Californium-241

| rowspan=2|{{sup|241}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 143

| rowspan=2|241.06369(18)#

| rowspan=2|2.35(18) min

| β{{sup|+}} (85%)

| {{sup|241}}Bk

| rowspan=2|(7/2−)

| α (15%)

| {{sup|237}}Cm

|-id=Californium-242

| rowspan=3|{{sup|242}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 144

| rowspan=3|242.063755(14)

| rowspan=3|3.49(15) min

| α (61%)

| {{sup|238}}Cm

| rowspan=3|0+

| β{{sup|+}} (39%)

| {{sup|242}}Bk

| SF (<0.014%)

| (various)

|-id=Californium-243

| rowspan=2|{{sup|243}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 145

| rowspan=2|243.06548(19)#

| rowspan=2|10.8(3) min

| β{{sup|+}} (86%)

| {{sup|243}}Bk

| rowspan=2|(1/2+)

| α (14%)

| {{sup|239}}Cm

|-id=Californium-244

| rowspan=2|{{sup|244}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 146

| rowspan=2|244.0659994(28)

| rowspan=2|19.5(5) min

| α (75%)

| {{sup|240}}Cm

| rowspan=2|0+

| EC (25%)

| {{sup|244}}Bk

|-id=Californium-245

| rowspan=2|{{sup|245}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 147

| rowspan=2|245.0680468(26)

| rowspan=2|45.0(15) min

| β{{sup|+}} (64.7%)

| {{sup|245}}Bk

| rowspan=2|1/2+

| α (35.3%)

| {{sup|241}}Cm

|-id=Californium-245m

| style="text-indent:1em" | {{sup|245m}}Cf

| colspan="3" style="text-indent:2em" | 57(4) keV

| >100# ns

| IT

| {{sup|245}}Cf

| (7/2+)

|-id=Californium-246

| rowspan=3|{{sup|246}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 148

| rowspan=3|246.0688037(16)

| rowspan=3|35.7(5) h

| α

| {{sup|242}}Cm

| rowspan=3|0+

| SF (2.4×10{{sup|−4}}%)

| (various)

| EC?

| {{sup|246}}Bk

|-id=Californium-247

| rowspan=2|{{sup|247}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 149

| rowspan=2|247.070971(15)

| rowspan=2|3.11(3) h

| EC (99.965%)

| {{sup|247}}Bk

| rowspan=2|(7/2+)

| α (.035%)

| {{sup|243}}Cm

|-id=Californium-248

| rowspan=2|{{sup|248}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 150

| rowspan=2|248.0721829(55)

| rowspan=2|333.5(28) d

| α (99.997%)

| {{sup|244}}Cm

| rowspan=2|0+

| SF (.0029%)

| (various)

|-id=Californium-249

| rowspan=2|{{sup|249}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 151

| rowspan=2|249.0748504(13)

| rowspan=2|351(2) y

| α

| {{sup|245}}Cm

| rowspan=2|9/2−

| SF (5×10{{sup|−7}}%)

| (various)

|-id=Californium-249m

| style="text-indent:1em" | {{sup|249m}}Cf

| colspan="3" style="text-indent:2em" | 144.98(5) keV

| 45(5) μs

| IT

| {{sup|249}}Cf

| 5/2+

|-id=Californium-250

| rowspan=2|{{sup|250}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 152

| rowspan=2|250.0764045(17)

| rowspan=2|13.08(9) y

| α (99.923%)

| {{sup|246}}Cm

| rowspan=2|0+

| SF (.077%)

| (various)

|-id=Californium-251

| {{sup|251}}CfHigh neutron cross-section, tends to absorb neutrons

| style="text-align:right" | 98

| style="text-align:right" | 153

| 251.0795872(42)

| 898(44) y

| α

| {{sup|247}}Cm

| 1/2+

|-id=Californium-251m

| style="text-indent:1em" | {{sup|251m}}Cf

| colspan="3" style="text-indent:2em" | 370.47(3) keV

| 1.3(1) μs

| IT

| {{sup|251}}Cf

| 11/2−

| rowspan=2|{{sup|252}}CfMost common isotope

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 154

| rowspan=2|252.0816265(25)

| rowspan=2|2.645(8) y

| α (96.8972%)

| {{sup|248}}Cm

| rowspan=2|0+

| SF (3.1028%)High neutron emitter, average 3.7 neutrons per fission

| (various)

|-id=Californium-253

| rowspan=2|{{sup|253}}Cf

| rowspan=2 style="text-align:right" | 98

| rowspan=2 style="text-align:right" | 155

| rowspan=2|253.0851337(46)

| rowspan=2|17.81(8) d

| β{{sup|−}} (99.69%)

| {{sup|253}}Es

| rowspan=2|(7/2+)

| α (.31%)

| {{sup|249}}Cm

|-id=Californium-254

| rowspan=3|{{sup|254}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 156

| rowspan=3|254.087324(12)

| rowspan=3|60.5(2) d

| SF (99.69%)

| (various)

| rowspan=3|0+

| α (.31%)

| {{sup|250}}Cm

| Double beta decay?

| {{sup|254}}Fm

|-id=Californium-255

| rowspan=3|{{sup|255}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 157

| rowspan=3|255.09105(22)#

| rowspan=3|85(18) min

| β{{sup|−}}

| {{sup|255}}Es

| rowspan=3|(7/2+)

| SF?

| (various)

| α?

| {{sup|251}}Cm

|-id=Californium-256

| rowspan=3|{{sup|256}}Cf

| rowspan=3 style="text-align:right" | 98

| rowspan=3 style="text-align:right" | 158

| rowspan=3|256.09344(34)#

| rowspan=3|12.3(12) min

| SF

| (various)

| rowspan=3|0+

| α?

| {{sup|252}}Cm

| β{{sup|−}}β{{sup|−}}?

| {{sup|256}}Fm

Actinides vs fission products

Californium-252

File:Cf 252 Produktion.png

Californium-252 (Cf-252, {{sup|252}}Cf) 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.{{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 }}

This isotope produces high neutron emissions and has a number of uses in industries such as nuclear energy, medicine, and petrochemical exploration.

= Nuclear reactors =

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 =

The portable isotopic neutron spectroscopy (PINS) used by United States Armed Forces, the National Guard, Homeland Security, and Customs and Border Protection, uses {{sup|252}}Cf sources to detect hazardous contents inside artillery projectiles, mortar projectiles, rockets, bombs, land mines, and improvised explosive devices (IED).{{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}}{{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/}}

= Oil and petroleum =

In the oil industry, {{sup|252}}Cf 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.{{Cite web|title = Californium-252 & Antimony-Beryllium Sources|url = http://www.frontier-cf252.com|website = Frontier Technology Corp.|access-date = 2016-02-24}}

= Medicine =

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.{{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}}

References

Sources

{{cite book

| title = Handbook of Chemistry and Physics

| editor-first = David R.|editor-last = Lide

| edition = 87th

| date = 2006

| publisher = CRC Press, Taylor & Francis Group

| isbn = 978-0-8493-0487-3

| ref = {{sfnRef|CRC|2006}}

}}

Category:Californium

Californium