Speaker
Description
The recent experimental campaign using the ν-Ball2 state-of-the-art hybrid gamma-ray spectrometer at the ALTO facility of IJC Lab in Orsay will be reviewed. ν-Ball2 consists of several coupled detectors and devices, including Gammapool high efficiency Ge clovers, the FATIMA fast-timing array [1], eight clusters of the PARIS array [2] and the DSSD segmented silicon detector from Warsaw [3]. A major focus of the experimental campaign was to perform gamma ray spectroscopy of nuclear fission, induced by fast neutrons from the LICORNE source [4], light charged particles, and heavy ion beams from the ALTO tandem accelerator. These reactions are used as tools to study both the fission process itself and as a production mechanism for studying exotic neutron-rich nuclei and the lifetimes of their excited states. Open questions in fission have been addressed, such as the evolution of fragment yield distributions in the sub-actinide region [5] and the emission of high energy gamma rays in nuclear fission with potential population of collective resonances (PDR, GDR, etc.) in the emerging fragments [6]. Additional questions on angular correlations between fission fragment partner spins, and gamma ray angular distributions with respect to the fission axis are currently being addressed [7]. An overview of the ν-Ball2 experimental campaign will be given and along with some selected physics highlights and future prospects.
[1] M. Rudigier et al., Nucl.Instrum.Meth.A, 969, (2020), 163967
[2] F. Camera and A. Maj, PARIS White Book, ISBN 978-83-63542-22-1 (2021)
[3] https://www.slcj.uw.edu.pl/en/coulomb-excitation-at-the-warsaw-cyclotron/
[4] J.N. Wilson et al., Physics Procedia, 59, (2014), Pages 31-36
[5] A. Andreyev et al., Phys. Rev. Lett. 105, (2010) 252502
[6] H. Makii et al. Phys. Rev. C 100, (2019) 044610
[7] J. Randrup, Phys. Rev. C 106, (2022) L051601