Isotopes of californium explained

Californium (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 Cf in 1950. There are 20 known radioisotopes ranging from Cf to Cf and one nuclear isomer, Cf. The longest-lived isotope is Cf with a half-life of 898 years.

List of isotopes

|-| rowspan=3|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%)| Cm| rowspan=3|5/2+#|-| SF (30%)| (various)|-| β (rare)| Bk|-| rowspan=2|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| SF[1] | (various)| rowspan=2|0+|-| α (<5%)| Cm|-| rowspan=2|Cf[2] | 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%)| Cm| rowspan=2|(5/2+)|-| β (35%)| Bk|-| rowspan=3|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%)| Cm| rowspan=3|0+|-| SF (1.5%)| (various)|-| β?| Bk|-| rowspan=2|Cf[2] | 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 (85%)| Bk| rowspan=2|(7/2−)|-| α (15%)| Cm|-| rowspan=3|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%)| Cm| rowspan=3|0+|-| β (39%)| Bk|-| SF (<0.014%)| (various)|-| rowspan=2|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 (86%)| Bk| rowspan=2|(1/2+)|-| α (14%)| Cm|-| rowspan=2|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%)| Cm| rowspan=2|0+|-| EC (25%)| Bk|-| rowspan=2|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 (64.7%)| Bk| rowspan=2|1/2+|-| α (35.3%)| Cm|-| style="text-indent:1em" | Cf| colspan="3" style="text-indent:2em" | 57(4) keV| >100# ns| IT| Cf| (7/2+)|-| rowspan=3|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| Cm| rowspan=3|0+|-| SF (2.4×10%)| (various)|-| EC?| Bk|-| rowspan=2|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%)| Bk| rowspan=2|(7/2+)|-| α (.035%)| Cm|-| rowspan=2|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%)| Cm| rowspan=2|0+|-| SF (.0029%)| (various)|-| rowspan=2|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| Cm| rowspan=2|9/2−|-| SF (5×10%)| (various)|-| style="text-indent:1em" | Cf| colspan="3" style="text-indent:2em" | 144.98(5) keV| 45(5) μs| IT| Cf| 5/2+|-| rowspan=2|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%)| Cm| rowspan=2|0+|-| SF (.077%)| (various)|-| Cf[3] | style="text-align:right" | 98| style="text-align:right" | 153| 251.0795872(42)| 898(44) y| α| Cm| 1/2+|-| style="text-indent:1em" | Cf| colspan="3" style="text-indent:2em" | 370.47(3) keV| 1.3(1) μs| IT| Cf| 11/2−|-| rowspan=2|Cf[4] | 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%)| Cm| rowspan=2|0+|-| SF (3.1028%)[5] | (various)|-| rowspan=2|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 (99.69%)| Es| rowspan=2|(7/2+)|-| α (.31%)| Cm|-| rowspan=3|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%)| Cm|-| ββ?| Fm|-| rowspan=3|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| Es| rowspan=3|(7/2+)|-| SF?| (various)|-| α?| Cm|-| rowspan=3|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?| Cm|-| ββ?| Fm|-

Actinides vs fission products

Californium-252

Californium-252 (Cf-252, Cf) undergoes spontaneous fission with a branching ratio of 3.09% and is used in small sized 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.[6]

This isotope produces high neutron emissions and can be used for a number of applications in industries such as nuclear energy, medicine, and petrochemical exploration.

Nuclear reactors

Neutron sources using Cf are most notably used in the start-up of nuclear reactors. Once a reactor is filled with nuclear fuel, the stable neutron emission from the source material 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 Cf sources to detect hazardous contents inside artillery projectiles, mortar projectiles, rockets, bombs, land mines, and improvised explosive devices (IED).[7] [8]

Oil and petroleum

In the oil industry, 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.[9]

Medicine

Cf has also been used in the treatment of serious forms of cancer. For certain types of brain and cervical cancer, Cf can be used as a more cost-effective substitute for radium.[10]

Sources

Notes and References

  1. Lightest nuclide known to undergo spontaneous fission as its main decay mode
  2. 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. . α decay of Fm 243 143 and Fm 245 145, and of their daughter nuclei . Physical Review C . 12 October 2020 . 102 . 4 . 044312 . 10.1103/PhysRevC.102.044312 . 241259726 . 24 June 2023 . en . 2469-9985.
  3. High neutron cross-section, tends to absorb neutrons
  4. Most common isotope
  5. High neutron emitter, average 3.7 neutrons per fission
  6. Radiation Quality of Californium-252. Physics in Medicine and Biology. J. F.. Dicello . Gross . W. . Kraljevic . U. . 1972 . 10.1088/0031-9155/17/3/301 . 17 . 3 . 345–355. 5070445. 1972PMB....17..345D . 250786668 .
  7. Web site: Portable Isotopic Neutron Spectroscopy (PINS) for the Military. Frontier Technology Corp.. 2016-02-24. 2018-06-16. https://web.archive.org/web/20180616132135/http://www.frontier-cf252.com/portable-isotopic-neutron-spectroscopy-military.html. dead.
  8. Production, distribution and applications of californium-252 neutron sources. Applied Radiation and Isotopes. 2000-11-01. 0969-8043. 11003521. 785–792. 53. 4–5. R. C.. Martin. J. B.. Knauer. P. A.. Balo. 10.1016/s0969-8043(00)00214-1.
  9. Web site: Californium-252 & Antimony-Beryllium Sources. Frontier Technology Corp.. 2016-02-24.
  10. Five-year cure of cervical cancer treated using californium-252 neutron brachytherapy. American Journal of Clinical Oncology. 1984-10-01. 0277-3732. 6391143. 487–493. 7. 5. Y.. Maruyama. J. R.. van Nagell. J.. Yoneda. E.. Donaldson. M.. Hanson. A.. Martin. L. C.. Wilson. C. W.. Coffey. J.. Feola. 10.1097/00000421-198410000-00018. 12553815.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes of californium".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.