https://doi.org/10.1140/epja/i2015-15065-4
Regular Article - Experimental Physics
First direct high-precision energy determination for the 8.4 and 20.7 keV nuclear transitions in 169Tm
1
Laboratory of Nuclear Problems, JINR, Dubna, Moscow Region, Russian Federation
2
Institute of Applied Physics, National University, Tashkent, Republic of Uzbekistan
3
Nuclear Physics Institute of the ASCR, CZ-25068, Řež near Prague, Czech Republic
4
National Research Nuclear University MEPhI, 115409, Moscow, Russian Federation
* e-mail: inoyatov@jinr.ru
Received:
20
February
2015
Revised:
16
April
2015
Accepted:
26
April
2015
Published online:
1
June
2015
Energies of 8410.1 ± 0.4, 20743.9 ± 0.3, and 63121.6 ± 1.2 eV were determined for the 8.4 keV M1 + E2, 20.7 keV M1 + E2, and 63.1 keV E1 nuclear transitions in 169Tm (generated in the EC decay of 169Yb, respectively, by means of the internal conversion electron spectroscopy. The 169Yb sources used were prepared by vacuum evaporation deposition on polycrystalline carbon and platinum foils as well as by ion implantation at 30keV into a polycrystalline aluminum foil. The relevant conversion electron spectra were measured by a high-resolution combined electrostatic electron spectrometer at 7 eV instrumental resoluition. Values of 0.0326(14) and 0.0259(17) were derived from our experimental data for the E2 admixture parameter |δ (E2/M1)| for the 8.4 and 20.7 keV transitions, respectively. A possible effect of nuclear structure on multipolarity of the 20.7 keV transition was also investigated.
© SIF, Springer-Verlag Berlin Heidelberg, 2015