Speaker
Description
Atomic masses are indispensable in nuclear structure and astrophysics research, and Penning-traps enable to determine atomic masses with exceptional precision and accuracy [1]. TRIGA-Trap is a high-precision, double Penning-trap mass spectrometer located in the reactor hall of the TRIGA research reactor in Mainz, Germany, where mass measurements of heavy radioactive nuclides -- particularly actinides -- are performed with the PI-ICR (Phase-Imaging Ion-Cyclotron Resonance) technique [2,3]. Latest mass measurements of nuclides in the vicinity of the deformed sub-shell closure at neutron number N=152 -- namely Pu-244, Am-241, Am-243, Cm-248, and Cf-249 -- have achieved uncertainties at the parts-per-billion (ppb) level and will be included in the upcoming AME (Atomic Mass Evaluation) dataset [4]. These precise mass measurements have been used to explore nuclear structure through mass filters, such as S_2n (two-neutron separation energies) and delta V_(p,n) (average p-n interaction of the most loosely-bound two nucleons), as well as their differentials [4]. Recently, mass measurements in the Pu isotopic chain -- including Pu-238, Pu-239, Pu-240, and Pu-242 -- have been performed. These will enhance the current dataset and contribute to ongoing nuclear structure studies. In particular, the shell evolution with increase in neutron number N towards the N=152 sub-shell closure for proton number Z=94 can be investigated, and the predictive capabilities of various nuclear shell models for heavy and deformed nuclei can be assessed. Lastly, preparations for mass measurement of Bk-249 are also underway. This presentation will provide an overview of the current status of the TRIGA-Trap experiment, discuss recent results along with their application in nuclear structure evaluation, and outline future prospects. References: [1] J. Dilling, K. Blaum, M. Brodeur et al. Annu. Rev. Nucl. Part. Sci. 68(1) (2018). [2] S. Eliseev, K. Blaum, M. Block et al. Phys. Rev. Lett.110(8), 082501 (2013). [3] S. Chenmarev, S. Nagy, J.J.W. van de Laar et al. Eur. Phys. J. A 59(2), 29 (2023). [4] S. Chenmarev, K. Blaum, M. Block et al. Eur. Phys. J. A 60, 204 (2024)
