Europium isotope

Europium has been identified spectroscopically in the sun and certain stars. Seventeen isotopes are now recognized. Europium isotopes are good neutron absorbers and are being studied for use in nuclear control applications. 

Europium is used for the capture of thermal neutrons for nuclear control rods in atomic power stations. Thermal neutron absorption of the natural mixture of europium isotopes is 4,600 barns. While its salts are used in coatings for cathode ray tubes in color televisions, organoderivatives are used in NMR spectroscopy. 

The element europium exists in nature as two isotopes 151Eu has a mass of 150.9196 amu, and 153Eu has a mass of 152.9209 amu. The average atomic mass of europium is 151.96 amu. Calculate the relative abundance of the two europium isotopes. 

Within this general picture, the measured spins and moments give complementary information on the nuclear single-particle structure. Here, I will briefly discuss the ground-state structure of odd-neutron nuclei in the rare-earth region, and, as an example of odd-proton nuclei, the sequence of europium isotopes. 

Fig. 5 Experimental nuclear moments of the sequence of I = 5/2 europium isotopes in the range Eu [1, 47]. The neutron-shell closure at N = 82 and the shape transition between N = 88 and N = 90 are well reflected in the data.

The doubly-odd europium isotopes in the range Eu are well described by the dj proton state coupled to the different neutron-shell model states, discussed above in connection ivith the odd-neution nuclei d in Eu, h Q in Eu and in i4 -i5ogjj gy usjug g-factors of the neighbouring odd-A nuclei and the additivity theorem, tiie magnetic moments of these doubly-odd europium isotopes are weU reproduced. The strongly deformed Eu and Eu are shown to be due to the configurations 3 (p[413 5/2] n[505 11/2]) and 0 (p[413 5 ] n[642 5/2]), respectively. 

ENDOR measurements of the transferred hyperfine interaction parameters A, (all in MHz) for the nearest fluorine neighbours of two divalent lanthanide ions substituting for Ca in CaFj. The measurements on Eu are by Baker and Hurrell (1963), and on Tm by Bessent and Hayes (1965). Hyperfine constants for the two europium isotopes are given in table 3 for Tm the ENDOR measurements of Bessent and Hayes give g = ( + )3.443(2), A = (-)l 101.376(4)MHz, for the single stable isotope of mass 169 I =2). 

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