Thulium-170
- 1 min read
- 2 chapters
Related on Lably
Through Nuclear binding energy, Beta decay and Spin (physics)
Properties
Thulium-170 has a binding energy of 8105.5144(43) keV per nucleon and a half-life of 128.6±0.3 d. It decays by β− decay to 170Yb about 99.869% of the time, and by electron capture to 170Er about 0.131% of the time. About 18.1% of β− decays populate a narrow excited state of 170Yb at 84.25474(8) keV (t1/2 = 1.61 ± 0.02 ns), and this is the main X-ray emission from 170Tm; lower bands are also produced through X-ray fluorescence at 7.42, 51.354, 52.389, 59.159, 59.383, and 60.962 keV.
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.
Sign in to keep reading
One more chapter is free with a Lably account.
Proposed applications
As a rare-earth element, thulium-170 can be used as the pure metal or thulium hydride, but most commonly thulium oxide due to the refractory properties of that compound. The isotope can be prepared in a medium-strength reactor by neutron irradiation of natural thulium, which has a high neutron capture cross section of 103 barns.
Medicine
In 1953, the Atomic Energy Research Establishment introduced thulium-170 as a candidate for radiography in medical and steelmaking contexts, but this was deemed unsuitable due to the predominant high-energy bremsstrahlung radiation, poor results on thin specimens, and long exposure times. 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.
Radiothermal generator
As the oxide (Tm2O3), thulium-170 has been proposed as a radiothermal source due to it being safer, cheaper, and more environmentally friendly than commonly used isotopes such as plutonium-238. 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.