Gießen 2024 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HK: Fachverband Physik der Hadronen und Kerne
HK 66: Structure and Dynamics of Nuclei XIII
HK 66.3: Vortrag
Donnerstag, 14. März 2024, 16:15–16:30, HBR 19: C 5b
Search for the double-alpha decay of radium isotopes — •Makar Simonov for the Double Alpha collaboration — Justus-Liebig-Universität Gießen, Gießen, Germany
Double-alpha decay is a predicted nuclear decay mode where the nucleus emits two α-particles simultaneously. This process was first considered in the 1980s as a sequence of 8Be-cluster emission followed by its disintegration. According to a recent study (Mercier et al., PRL 127, 012501 (2021)), immediate double-alpha decay is more likely to occur than 8Be-like cluster decay by more than 9 orders of magnitude, and it might be detected as a back-to-back emission of two α-particles.
To verify the prediction, two complementary experiments were conducted: an offline one at the FRS Ion Catcher (GSI, 4 months, 2022) and an online one at the ISOLDE (CERN, 1 week, 2023). At the FRS Ion Catcher, a 228Th source was used to produce recoil nuclei of 224Ra. The filtered beam was implanted on a foil, and two double-sided silicon strip detectors (DSSDs) located around the foil registered the energy, time, and spatial position of α-particles observed by the detectors. At ISOLDE, beams of 222Ra and 220Ra were generated by impinging a proton beam on a uranium target. The setup included four DSSDs triggered by coincidence events only. The expected number of detected double-alpha decays for both experiments is about 100.
In this talk, we will focus on data analysis for the FRS Ion Catcher experiment. We will examine key factors of DSSD calibration: detector geometry, energy and time resolution, and the use of Monte Carlo simulation as a tool to estimate the background.
Keywords: Double-alpha decay; Radioactive decay