Investigating Shell Structure: Mass Measurements of Sc, Ti, and V Isotopes at new magic N = 32 and N = 34

In this study, we present our findings on the precise mass measurements of ⁵⁵Sc, ^55-58Ti, and ^55-59V isotopes. These measurements were obtained during the initial commissioning campaign of the ZD-MRTOF system at the RIBF/RIKEN. Our focus is to examine the implications of these masses on the shell structure at N=32 and N=34, specifically in relation to the deformation towards N=40. The experimental setup, newly installed downstream of the ZeroDegree (ZD) spectrometer at the BigRIPS facility (RIBF/RIKEN), consists of a radiofrequency (RF) carpet-type helium gas cell combined with a multi-reflection time-of-flight (MRTOF) mass spectrograph. In the first low-energy experiment conducted at BigRIPS, high-energy products were decelerated and captured in helium gas. Subsequently, they were extracted through an aperture via RF microstructure into a Paul trap ion guide structure. The cooled and thermalized ions were then injected into the MRTOF system, forming a high-quality beam for conducting high-precision mass measurements. We provide a detailed account of the new cryogenic gas cell and the mass analysis methods employed in this experiment. Additionally, we outline our future plans for mass measurements, particularly focusing on the N=126 region. This region is of significant interest as it is proximate to waiting point nuclei relevant to the third peak of the r-process.