May 2 – 6, 2022
Europe/Rome timezone

Low level measurements for rare nuclear transitions in Hf isotopes

May 3, 2022, 9:40 AM
"E. Fermi" conference room (LNGS)

"E. Fermi" conference room


Via G. Acitelli, 22 67100 L'Aquila ITALY
Oral Presentation Fundamental Physics Fundamental physics


Alice Leoncini (Istituto Nazionale di Fisica Nucleare)


Recently, efforts have been made to improve the low-level measurements in Hf isotopes. In particular a passive approach, using a gamma-ray spectrometry technique, and active one, using the so-called “source = detector” approach have been adopted and here summarized. Both the techniques are implemented and optimized to investigate rare nuclear decays in Hf nuclides, such as $\alpha$ decay to the ground level and to the first excited state and double $\beta$ decays of $^{174}$Hf. An experiment to measure low-level radioactive contaminants of a Cs$_2$HfCl$_6$ (CHC) crystal scintillator has been carried out at the STELLA (SubTErranean Low Level Assay) facility at the Gran Sasso National Laboratory of the INFN, Italy. Such an experiment has preliminary profit of measurements using inductively coupled plasma mass spectrometry (ICP-MS) and HP-Ge diode to estimate the radiopurity level of the CHC. This crystal represents one of the promising new scintillating materials for $\gamma$ spectroscopy also in the field of low-level measurements. It offers a light output of more than 50000 photons/MeV, high energy resolution and an excellent ability for pulse shape discrimination (PSD) between $\gamma$($\beta$) and $\alpha$ particles. The residual contaminations of the CHC crystal with a mass of 6.90(1) g were estimated using the above-mentioned techniques. The results on rare nuclear transitions in Hf isotopes (mainly in the $^{174}$Hf isotope) and the perspectives of such measurements will be presented here.

Primary authors

Pierluigi Belli (Istituto Nazionale di Fisica Nucleare) Rita Bernabei (ROMA2) Fabio Cappella (Istituto Nazionale di Fisica Nucleare) Vincenzo Caracciolo (ROMA2) Riccardo Cerulli (Istituto Nazionale di Fisica Nucleare) Maria Antonella Incicchitti (Istituto Nazionale di Fisica Nucleare) Matthias Laubenstein (Istituto Nazionale di Fisica Nucleare) Alice Leoncini (Istituto Nazionale di Fisica Nucleare) Peng Wang (Department of Chemistry, Queen’s University, Kingston, ON K7L 3N6, Canada) Serge Nagorny (Gran Sasso Science Institute) Vittorio Merlo (Dipartimento di Fisica, Università di Roma Tor Vergata ) Stefano Nisi (LNGS)

Presentation materials