Installation of an underground laboratory for measuring low radioactivities and usage in context of transmutation research
Measuring of lowest specific activities of extremely long-lived isotopes has crucial importance for fundamental questions in nuclear and particle physics. These measurements can only take place underground because reduced natural background radiation is necessary.
The underground laboratory "Felsenkeller" established by VKTA Rossendorf represents a unique low background facility in Dresden for low background experiments.
Within this project the measuring conditions in this laboratory should be improved. It can be used for precision γ-spectroscopy of materials activated at the neutron facility (DT generator) of TU Dresden at HZDR. Furthermore a measuring setup for α-spectroscopy of extremely long-lived α-emitters and a setup for measuring isotopes decaying via electron capture (detecting x-rays) shall be installed.
The measurements can be used to predict the neutron induced background because of activation or (α,n) reactions in low background experiments (e.g. neutrinoless double beta decay). α-particles are produced in the decay chains of thorium or uranium which is contained in materials (e.g. concrete) in small fractions.
The long-lived α-emitter 144Nd should be measured in this project. Nd which contains 150Nd (a candidate for neutrinoless double beta deday) and 144Nd is used in the SNO+ experiment in a liquid scintillator. The background radiation produced by 144Nd has to be well understood for this high precision low background experiment.