In May 2022, the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) made significant strides by launching its precision measurement program. This program is facilitated by the Low Energy Beam and Ion Trap (LEBIT) facility staff at FRIB, who are responsible for taking high-energy, rare-isotope beams and cooling them to a lower energy state to conduct precise mass measurements of specific particles.
Led by Ryan Ringle and Georg Bollen, the LEBIT team recently published a research paper in which they verified the mass of aluminum-22, an exotic isotope known for its unique halo structure. This structure, characterized by protons loosely orbiting the nucleus, presents distinctive physical properties that pose interesting challenges for researchers. The successful measurement of aluminum-22’s mass represents a crucial milestone in FRIB’s scientific endeavors.
Understanding Halo Structures in Atoms
While most atoms exhibit electrons tightly orbiting the nucleus, the presence of halos composed of charged particles orbiting beyond the nucleus’s pull is a rare but fascinating occurrence. Protons and neutrons within the nucleus interact under specific conditions to form these halos, disrupting the conventional nuclear forces that hold them together. The rarity of halo structures, particularly those formed by protons, underscores the significance of FRIB’s research efforts.
The Experimental Process at FRIB
To explore the proton halo hypothesis surrounding aluminum-22, researchers at FRIB utilized a technique called “projectile fragmentation” to generate a high-energy isotope beam of the target element. By accelerating this beam to half the speed of light and directing it towards a target, the researchers created short-lived isotopes that were subsequently analyzed in precision mass measurements. This rigorous experimental process enabled the team to verify the existence of a proton halo in aluminum-22.
Moving forward, FRIB’s Beam Cooler and Laser Spectroscopy (BECOLA) facility is poised to continue the investigation by measuring the charge radius and nuclear deformation of aluminum-22. These additional measurements will provide further insights into the proton halo structure and solidify the research findings. Collaboration between theoretical physicists and experimentalists at FRIB remains crucial in advancing our understanding of rare isotopes and halo structures.
Impact of Student Involvement at FRIB
Notably, graduate students like Scott Campbell have played pivotal roles in the research conducted at FRIB. Campbell’s active participation in the aluminum-22 mass measurement project as part of his dissertation exemplifies the valuable contributions made by students at the facility. The unique opportunity for students to engage in cutting-edge research while balancing their academic commitments highlights the exceptional learning environment fostered at FRIB.
The precision measurement program at FRIB represents a groundbreaking initiative in the field of rare isotope research. By unraveling the mysteries of exotic isotopes like aluminum-22 and probing their halo structures, FRIB continues to push the boundaries of scientific exploration. The collaborative efforts of researchers, supported by state-of-the-art facilities, offer new perspectives on the fundamental properties of matter and open doors to exciting discoveries in nuclear physics.
Leave a Reply