Production of rare isotope beams with aligned nuclear spins opens up new possibilities for high-energy physics research

March 1, 2013
The RIBF facility. Spin-aligned beams of aluminum-32 (32Al) are produced in two stages by first bombarding a beryllium (Be) target with a calcium-48 (48Ca) beam generated by the superconducting ring cyclotron (SRC) to produce an aluminum-33 (33Al) beam, and then bombarding a secondary aluminum target and selecting a narrow band of momentum to produce a 32Al beam with high degree of spin alignment. Credit: 2012 Y. Ichikawa et al.

Particle physicists routinely and incrementally test the boundaries of what is possible in physics research. Occasionally however, they achieve a breakthrough that reveals an entirely new, uncharted field of study. Researchers at RIKEN's Radioactive Isotope Beam Factory (RIBF), part of the RIKEN Nishina Center for Accelerator-Based Science, have recently made such a breakthrough with their production of a beam of spin-aligned rare isotopes.

The nucleus of an atom consists of protons and neutrons, the numbers of which determine the element and the isotopic variant. Every element has a range of possible isotopes, but the vast majority of isotopes do not occur in nature—they can only be produced experimentally by bombarding materials such as thin metallic foils with a beam of ions using a

Researchers at the RIBF have been producing beams of rare and heavy isotopes to explore the unknown 'nuclear chart' for many years. The beam of isotopes produced by the RIBF has a random alignment of spins, a quantum of the isotope related to its . By passing the isotope beam through a slit, the beam can be pared down to a narrow range of momentum to afford a beam with enhanced spin alignment. This technique has been applied in the past as a system consisting of two target–slit stages, but the degree of spin alignment achieved had been marginal. In their latest work, the RIKEN researchers were able to improve the spin alignment effect by a factor of 50 by replacing the first slit with a much more effective momentum dispersion matching stage that relies on the divergent spread of isotope due to their differences in momentum.

"Our method expands research into radioisotope beams and offers new possibilities to conduct microscopic investigations into physical and that take advantage of nuclear properties such as spin," says Yuichi Ichikawa from the research team.

Not only does the new system produce a beam with a spin alignment of up to 8%, the ability of the momentum-dispersion matching stage to harvest a larger fraction of the initial isotope beam also greatly enhances the beam's overall intensity. The system can also be applied for a wide range of isotopes. "The RIBF is expected to produce 4,000 species of radioisotope beams," says Ichikawa. The production of such spin-aligned isotope beams is anticipated to open up new opportunities for research on unusual nuclear structures and the quantum dynamics of condensed matter.

Explore further: Argonne aiming for isotope lab

More information: Ichikawa, Y., et al. Production of spin-controlled rare isotope beams. Nature Physics 8, 918–922 (2012).

Related Stories

Argonne aiming for isotope lab

June 21, 2007

Argonne National Laboratory near Chicago and Michigan State University are top contenders for one of the world's most advanced science labs.

New type of nuclear fission discovered

December 6, 2010

( -- Nuclear fission, or the splitting of a heavy nucleus, usually results in symmetrical fragments of the same mass. Physicists attribute the few known examples of fission that is asymmetric to the formation ...

The importance of fundamental measurements

May 4, 2011

At the Radioactive Isotope Beam Facility (RIBF) of the RIKEN Nishina Center for Accelerator Science in Wako, a research team has measured the time it takes for 38 extremely rare isotopes to decay by half. This is the first ...

Emerging from the vortex

February 17, 2012

Whether a car or a ball, the forces acting on a body moving in a straight line are very different to those acting on one moving in tight curves. This maxim also holds true at microscopic scales. As such, a beam of electrons ...

Recommended for you

CERN collides heavy nuclei at new record high energy

November 25, 2015

The world's most powerful accelerator, the 27 km long Large Hadron Collider (LHC) operating at CERN in Geneva established collisions between lead nuclei, this morning, at the highest energies ever. The LHC has been colliding ...

'Material universe' yields surprising new particle

November 25, 2015

An international team of researchers has predicted the existence of a new type of particle called the type-II Weyl fermion in metallic materials. When subjected to a magnetic field, the materials containing the particle act ...

Exploring the physics of a chocolate fountain

November 24, 2015

A mathematics student has worked out the secrets of how chocolate behaves in a chocolate fountain, answering the age-old question of why the falling 'curtain' of chocolate surprisingly pulls inwards rather than going straight ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.