https://doi.org/10.1140/epja/i2012-12157-7
Regular Article - Experimental Physics
Search for 
decay of 151Eu to the first excited level of 147Pm using underground 
-ray spectrometry
1
Institute for Nuclear Research, MSP 03680, Kyiv, Ukraine
2
European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg, B-2440, Geel, Belgium
* e-mail: danevich@kinr.kiev.ua
Received:
15
July
2012
Accepted:
7
October
2012
Published online:
22
November
2012
The alpha decay of 151Eu to the first excited level of 147Pm (
, 
keV) was searched for at the HADES underground laboratory (
m w.e.). A sample of high-purity europium oxide with mass of 303g and a natural isotopic composition has been measured over 2232.8h with a high energy resolution ultra-low background n-type semi-planar HPGe detector (40 cm3) with sub-micron deadlayer. The new improved half-life limit has been set as 
y at 68% CL. Possibilities to improve the sensitivity of the experiment, which is already near the theoretical predictions, are discussed. New half-life limit for decay of 153Eu is also determined as 
y.
© SIF, Springer-Verlag Berlin Heidelberg, 2012
