The prototype for a scaled-down miniature particle accelerator successfully powered a free-electron laser, opening up avenues for new methods to analyze atoms, molecules, and condensed matter.
When people talk about particle accelerators, most of them usually refer to the Large Hadron Collider - a particle accelerator that runs for a total of 16.5 miles (27 kilometers) near Geneva, Switzerland. However, in the new study, the miniature particle accelerator is a lot smaller. Formally known as a plasma wakefield accelerator, the miniaturized equipment generates short and intense electron bursts, which is then used to power a free-electron laser (FEL). An FEL device generates synchrotron radiation, behaves like a laser in most cases, and observes elementary particles.
The new miniature particle accelerator is described in detail in the Nature article "Free-electron lasing at 27 nanometres based on a laser wakefield accelerator," published last July 21.
Opening New Possibilities in Particle Accelerator Design and Development
While there have been previous attempts at developing a miniature particle accelerator, the resulting laser pulses are not enough to be useful at smaller scales. In the new study, researchers from the Chinese Academy of Sciences (CAS) created a robust setup positioned in normal rooms while amplifying the resulting free-electron laser beam up to 100 times in the final stage.
"We proved the feasibility of the new technical route with the laser electron accelerator with ultra-high acceleration capability, and it downsized the facility size from kilometer level to 12 meters," says Leng Yuxin, a member of the research team also from CAS, in a news release from the academy.
They also noted that scaling down particle accelerator technology while keeping it useful posed a couple of challenges for the team. First, they had to narrow down the variation in the electron energy to just 0.5 percent - a task that required a series of optimization strategies that restricted electron acceleration to acceptable values and its smooth travel along with the prototype.
In a free-electron laser beam, electrons are first shot through a vacuum pipe, passing through a series of magnetized undulators - insertion devices with an alternating magnetic field. These magnetic fields "shake" the electrons to produce light. The generated light pushes the electrons back, creating small groups that then generate the final laser beam.
Allowing Particle Accelerator Technology in Smaller Locations
One key technology that allowed the researchers to create their miniature particle accelerator compact is increasing the electric field passing through the three undulators while keeping it stable. With the new design, researchers show that most benefits of particle accelerator technology can now be used in studies in a single room.
Not only is the miniature particle accelerator physically smaller compared to existing accelerators and FEL setups, but it also costs significantly less - opening up new applications, especially those that don't necessarily require the full power of the larger accelerators.
Describing the new technology, accelerator physicist Agostino Marinelli from the SLAC National Accelerator Laboratory calls it a "huge step forward" in an article from Science Magazine.
Check out more news and information on Particle Accelerators in Science Times.