Search for long-lived superheavy eka-tungsten with radiopure ZnWO${}_4$ crystal scintillator

Abstract

The data collected with a radioactively pure ZnWO${}_4$ crystal scintillator (699 g) in low background measurements during 2130 h at the underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (INFN, Italy) were used to set a limit on possible concentration of superheavy eka-W (seaborgium Sg, Z = 106) in the crystal. Assuming that one of the daughters in a chain of decays of the initial Sg nucleus decays with emission of high energy $\alpha$ particle ($Q_{\alpha }>8$ MeV) and analyzing the high energy part of the measured $\alpha$ spectrum, the limit N(Sg)/N(W) < 5.5 $\times$ 10${}^{-14}$ atoms/atom at 90% C.L. was obtained (for Sg half-life of 10${}^9$ yr). In addition, a limit on the concentration of eka-Bi was set by analysing the data collected with a large BGO scintillation bolometer in an experiment performed by another group [L. Cardani et al., JINST 7 (2012) P10022]: N(eka-Bi)/N(Bi) < 1.1 $\times$ 10${}^{-13}$ atoms/atom with 90% C.L. Both the limits are comparable with those obtained in recent experiments which instead look for spontaneous fission of superheavy elements or use the accelerator mass spectrometry.

arXiv comment9 pages, 2 figures; in press on Physica Scripta

References in corpus (13)

• Heavy particle radioactivities of superheavy nuclei
• Shell Corrections of Superheavy Nuclei in Self-Consistent Calculations
• Shell stabilization of super- and hyperheavy nuclei without magic gaps
• Fission half-lives of super-heavy nuclei in a microscopic approach
• ZnWO_4 crystals as detectors for double beta decay and dark matter experiments
• Have Superheavy Elements been Produced in Nature?
• Search for double beta decay of Zinc and Tungsten with the help of low-background ZnWO4 crystal scintillators
• Radioactive contamination of ZnWO4 crystal scintillators
• Nuclear Half-Lives for Alpha Radioactivity of Elements with 100 $\le$ Z $\le$ 130
• Evidence for a long-lived superheavy nucleus with atomic mass number A=292 and atomic number Z=~122 in natural Th
• Discovery of Isotopes of Elements with Z $\ge$ 100
• Existence of long-lived isotopes of a superheavy element in natural Au
• ICP-SFMS search for long-lived naturally-occurring heavy, superheavy and superactinide nuclei compared to AMS experiments

Cited by in corpus (1)

• Improvement of radiopurity level of enriched ${}^{116}$CdWO${}_4$ and ZnWO${}_4$ crystal scintillators by recrystallization