Europium is a chemical element, with the symbol Eu and atomic number 63.
Like all isotopes of lanthanides low in neutron, europium has a good capacity to
absorb neutrons. We have also studied its use in nuclear reactors. Mostly the
control rods for nuclear reactors in Russian submarines use europium. The cross
section is 2,980 barns and the two stable isotopes are capturing.
Europium is a fission product, whose fission yields are low because the numbers
of nucleons are close to the upper limit of large fission fragments. The most
stable isotopes formed are:
on the one hand, the europium 151 (stable) by beta decay of the samarium 151
(period 96.6 years) which is a neutron poison (15,000 barns of cross section)
which mainly turns into samarium 152 (stable) in the course the operation of the
reactor;
on the one hand europium 153 (stable) formed by beta decay of the samarium 153
(period 46.8 h);
on the other hand europium 155 (period 4.76 years) which is a neutron poison
which is found among short-lived waste;
on the other hand europium 156 (period 15 days).
In April 2018, while China and Australia are the main producers of rare earths,
in the journal Nature of Japanese researchers estimate that the new deposits
detected in eastern Japan represent
over 2,500 km2 about 16 million tonnes of rare earths, located in the marine
sediment, more than 5,000 meters deep; over 2,499 km2, the bottom there would
contain more than 16 million tonnes of rare earth oxides, i.e. 620 years of
world supply of Europium (and also 780 years of yttrium reserve, 730 years for
dysprosium, 420 years for terbium, according to an April 2018 publication in
Scientific Reports12,13.
Romania has rare earth mines producing europium and dysprosium. Closed in the
1980s, we plan to reopen them in 2019
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rhenium germanium zirconium cadmium hafnium
barium lithium beryllium strontium calcium
Tantalum gadolinium samarium yttrium ytterbium
Lutetium praseodymium holmium erbium thulium dysprosium
terbium europium lanthanum cerium neodymium scandium
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