Physics:Thulium-170
| General | |
|---|---|
| Symbol | 170Tm |
| Names | thulium-170, Tm-170 |
| Protons | 69 |
| Neutrons | 101 |
| Nuclide data | |
| Natural abundance | Synthetic |
| Half-life | 128.6±0.3 d[1] |
| Decay products | 170Yb 170Er |
| Isotope mass | 169.93580709(79)[2] u |
| Spin | 1−[1] |
| Binding energy | 1377937.45±0.73[1] keV |
| Decay modes | |
| Decay mode | Decay energy (MeV) |
| β− | 0.968[3] |
| EC | 0.312[3] |
| Isotopes of Chemistry:thulium Complete table of nuclides | |
Thulium-170 (170Tm or Tm-170) is a radioactive isotope of thulium proposed for use in radiotherapy and in radioisotope thermoelectric generators.
Properties
Thulium-170 has a half-life of 128.6 days, decaying by β− to 170Yb about 99.87% of the time, and by electron capture to 170Er about 0.13% of the time.[1] About 18.1% of β− decays populate an excited state of 170Yb at 84.25474(8) keV and this produces the main gamma ray emission from 170Tm; lower-energy photons are also produced through X-ray fluorescence at 7.42, 51.354, 52.389, 59.159, 59.383, and 60.962 keV.[3][4]
The ground state of thulium-170 has a spin of 1−. The charge radius is 5.2303(36) fm, the magnetic moment is 0.2458(17) μN, and the electric quadrupole moment is 0.72(5) e⋅b.[5]
Proposed applications
As a rare-earth element, thulium-170 can be used as the pure metal or thulium hydride, but the most common form is as thulium oxide (Tm
2O
3) due to the refractory properties of that compound.[6][7] The isotope can be prepared in a reactor by neutron irradiation of natural thulium, which has a high neutron capture cross section of 103 barns.[4][7]
Medicine
In 1953, the Atomic Energy Research Establishment introduced thulium-170 as a candidate for radiography in medical and steelmaking contexts,[8] but this was deemed unsuitable due to the predominant high-energy bremsstrahlung radiation, poor results on thin specimens, and long exposure times.[9] However, 170Tm has been proposed for radiotherapy because the isotope is simple to prepare into a biocompatible form, and the low-energy radiation can selectively irradiate diseased tissue without causing collateral damage.[4][10]
Radiothermal generator
170
Tm
2O
3 has been proposed as a radiothermal source due to it being safer, cheaper, and more environmentally friendly than commonly used materials that contain isotopes such as plutonium-238.[11][12] The heat output from a 170Tm source is initially much greater than from a 238Pu source relative to mass, but it declines rapidly due to its shorter half-life.[7]
References
- ↑ 1.0 1.1 1.2 1.3 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties". Chinese Physics C 45 (3). doi:10.1088/1674-1137/abddae. https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf.
- ↑ Template:AME2020 II
- ↑ 3.0 3.1 3.2 3.3 "NuDat 3". https://www.nndc.bnl.gov/nudat3/.
- ↑ 4.0 4.1 4.2 4.3 Polyak, Andras; Das, Tapas; Chakraborty, Sudipta; Kiraly, Reka; Dabasi, Gabriella; Joba, Robert Peter; Jakab, Csaba; Thuroczy, Julianna et al. (October 2014). "Thulium-170-Labeled Microparticles for Local Radiotherapy: Preliminary Studies" (in en). Cancer Biotherapy and Radiopharmaceuticals 29 (8): 330–338. doi:10.1089/cbr.2014.1680. ISSN 1084-9785. PMID 25226213. https://www.academia.edu/13307480/Thulium_170_Labeled_Microparticles_for_Local_Radiotherapy_Preliminary_Studies.
- ↑ Mertzimekis, Theo J.. "NUMOR | Nuclear Moments and Radii | University of Athens | since 2007". https://magneticmoments.info/numor/isotope_measurement_results.php?Z=69&A=170.
- ↑ 6.0 6.1 Walter, C.E.; Van Konynenburg, R.; VanSant, J.H. (6 September 1990). "Thulium-170 heat source". doi:10.2172/10156110. https://www.osti.gov/biblio/10156110.
- ↑ 7.0 7.1 7.2 7.3 Dustin, J. Seth; Borrelli, R.A. (December 2021). "Assessment of alternative radionuclides for use in a radioisotope thermoelectric generator". Nuclear Engineering and Design 385. doi:10.1016/j.nucengdes.2021.111475. https://www.osti.gov/biblio/1832380.
- ↑ Hilbish, Theodore F. (November 1954). "Developments in diagnostic radiology". Public Health Reports 69 (11): 1017–1027. doi:10.2307/4588947. ISSN 0094-6214. PMID 13215708.
- ↑ 9.0 9.1 Halmshaw, Ronald (1995). Industrial radiology: theory and practice (2. ed.). London: Chapman & Hall. pp. 59–60. ISBN 0-412-62780-9.
- ↑ 10.0 10.1 Vats, Kusum; Das, Tapas; Sarma, Haladhar D.; Banerjee, Sharmila; Pillai, M.r.a. (December 2013). "Radiolabeling, Stability Studies, and Pharmacokinetic Evaluation of Thulium-170-Labeled Acyclic and Cyclic Polyaminopolyphosphonic Acids". Cancer Biotherapy and Radiopharmaceuticals 28 (10): 737–745. doi:10.1089/cbr.2013.1475. ISSN 1084-9785. PMID 23931111. https://d1wqtxts1xzle7.cloudfront.net/39452235/Polyak_et_al_-_Thulium-170-Labeled_Micro20151027-29202-1id84pt-libre.pdf?1445936337=&response-content-disposition=inline%3B+filename%3DPolyak_et_al_Thulium_170_Labeled_Micropa.pdf&Expires=1699819769&Signature=AGjXXJasvYKkKtVfZYGDWFXSCDcNEBgFrVjZ4wGQ9Nk6NwTu7leQ0zJiaZt~YpgKoKuCqxfMtfJ-BLM1mZQIIMdj-CdX7uEI49jeVOZRqWkv1wPCYjqSuZx2V~KAB5s9nqDeKtqIGNAYC-gQQKmDpdh-jkcObOZJ18WG-a-YPBc8o~7MOSF-41HZuypDeG38210-lTA8s5i4w4BXKJdns91BmY~GrJph1jR4JBHn0qRY8L-vw4lIIfBMDkptMiB-0A5eLt-mjpIH7D7rylwQ3Q0HcOUA39YsoS0q9EGdaXq9kTAfFWkgL88JlaUURsXWi-QVsqpaD~XH5Nx94MxQLQ__&Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA.
- ↑ 11.0 11.1 Walter, C. E. (1 July 1991). "Infrastructure for thulium-170 isotope power systems for autonomous underwater vehicle fleets" (in English). Lawrence Livermore National Lab., CA (United States). https://www.osti.gov/biblio/5491258.
- ↑ Alderman, Carol J. (1993). "Thulium heat sources for space power application". AIP Conference Proceedings. 271. pp. 1085–1091. doi:10.1063/1.43194.
| Lighter: thulium-169 |
Thulium-170 is an isotope of thulium |
Heavier: thulium-171 |
| Decay product of: — |
Decay chain of thulium-170 |
Decays to: erbium-170 ytterbium-170 |
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