Scientists accelerate uranium beam with record power

Scientists and engineers at the Rare Isotope Beam Facility (FRIB) have taken the next step in isotope studies. They accelerated a high-power uranium ion beam and delivered a record continuous beam power of 10.4 kilowatts to a target. The work is published in the journal Accelerators and Physical Examination Beams.

Uranium is the most difficult element to accelerate. Yet it is extremely important for scientific research. Of the more than 17 high-priority science programs using rare isotope beams identified by the National Academy of Sciences and the Nuclear Science Advisory Committee, more than half require a uranium primary beam.

Researchers like uranium because it can produce a wide variety of isotopes after fragmentation or fission.

The implementation of the acceleration of a uranium beam of unprecedented power constitutes a crucial step for FRIB. This achievement opens a new avenue of research on rare isotopes. During the first eight hours of operation, the high-power uranium beam allowed FRIB scientists to produce and identify three new isotopes: gallium-88, arsenic-93 and selenium-96 .

The high-power uranium beam required the stable operation of all accelerator devices at the highest acceleration gradients. This achievement creates a basis for delivering the heaviest ion beams to create rare isotopes. It extends scientific reach to unexplored regions of the nuclear landscape.

According to the study, the FRIB accelerator was capable of producing the highest power accelerated continuous wave uranium beam ever seen, leading to the separation and identification of three previously unknown isotopes.

This achievement was possible thanks to the successful exploitation of the FRIB, including a new superconducting linear accelerator consisting of 324 resonators in 46 cryomodules, a new liquid lithium etchant and new technologies such as the production of uranium in the ion of electron cyclotron resonance (ECR). source, the single heavy ion radio frequency quadrupole (RFQ), the high power target and the beam escape.

Researchers have developed new techniques to implement the simultaneous acceleration of three charge states of uranium after stripping with a film of liquid lithium.

This approach made it possible to achieve record power for uranium. The three previously unobserved isotopes – gallium-88, arsenic-83 and selenium-96 – were produced in a 1.2 mm graphite target, separated and identified for the first time in the advanced separator of rare isotopes of FRIB. This work was carried out in collaboration with scientists from the United States, Japan and South Korea.