Levitating particles could lift nuclear detective work

November 7, 2018, Los Alamos National Laboratory
Los Alamos scientists Alexander Malyzhenkov and Alonso Castro demonstrate levitating uranium particles with laser beams. Credit: Los Alamos National Laboratory

Laser-based 'optical tweezers' could levitate uranium and plutonium particles, thus allowing the measurement of nuclear recoil during radioactive decay. This technique, proposed by scientists at Los Alamos National Laboratory, provides a new method for conducting the radioactive particle analysis essential to nuclear forensics.

"Our idea relies on trapping a particle using 'optical tweezers,' a technique which is the subject of this year's Nobel prize in Physics," said Alonso Castro of the Lab's Actinide Analytical Chemistry group, one of the authors of a new paper in the journal Physical Review A. "It is only fitting that [Nobel prize winner] Arthur Ashkin's invention is still yielding novel science even after 30 years."

The team's work shows that, for micrometer and sub-micrometer , the kinetic energy of the emitted nuclear particle, or daughter particle, can be determined very accurately by measuring the recoil of the sample particle levitated in a laser-powered optical trap. The sample particle fully absorbs the recoil momentum of the daughter atom resulting in a well-defined oscillation in the harmonic potential of the trap.

"For applications such as nuclear forensic analysis, this technique could have significant value. Thus far, we have been able to hold uranium particles in optical traps, and we find that holding them in place, with their oscillation energy 'cooled,' gives us the opportunity to see the recoil when the daughter atom's motion causes displacement of the sample," said Castro.

"The next step would be to measure those displacements and then calculate the energy of the recoil. The impact of our approach is that it can very quickly determine the isotopic composition of the types of nanometer and micrometer-sized particles found in nuclear forensic scenarios," he said.

Nuclear forensics is the examination of nuclear and other radioactive materials to determine the origin and history of the materials in the context of law enforcement investigations or the assessment of nuclear security vulnerabilities. Los Alamos conducts a wide range of nuclear forensic science in support of the Laboratory's national security mission.

Explore further: Is nature exclusively left handed? Researchers study chilled atoms to find out

More information: Alexander Malyzhenkov et al, Nuclear recoil spectroscopy of levitated particles, Physical Review A (2018). DOI: 10.1103/PhysRevA.98.052103

Related Stories

Recommended for you

Scientists explain how wombats drop cubed poop

November 18, 2018

Wombats, the chubby and beloved, short-legged marsupials native to Australia, are central to a biological mystery in the animal kingdom: How do they produce cube-shaped poop? Patricia Yang, a postdoctoral fellow in mechanical ...

Helping Marvel superheroes to breathe

November 18, 2018

Marvel comics superheroes Ant-Man and the Wasp—nom de guerre stars of the eponymous 2018 film—possess the ability to temporarily shrink down to the size of insects, while retaining the mass and strength of their normal ...

Explaining a fastball's unexpected twist

November 18, 2018

An unexpected twist from a four-seam or a two-seam fastball can make the difference in a baseball team winning or losing the World Series. However, "some explanations regarding the different pitches are flat-out wrong," said ...

Scientists produce 3-D chemical maps of single bacteria

November 16, 2018

Scientists at the National Synchrotron Light Source II (NSLS-II)—a U.S. Department of Energy (DOE) Office of Science User Facility at DOE's Brookhaven National Laboratory—have used ultrabright x-rays to image single bacteria ...

Quantum science turns social

November 15, 2018

Researchers in a lab at Aarhus University have developed a versatile remote gaming interface that allowed external experts as well as hundreds of citizen scientists all over the world to optimize a quantum gas experiment ...

0 comments

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.