Lab successfully demonstrates new technique to improve particle beams

Physicists love to smash particles together and study the resulting chaos. Therein lies the discovery of new particles and strange physics, generated for tiny fractions of a second and recreating conditions often not seen ...

Researchers at the U.S. Department of Energy's Fermi National Accelerator Laboratory have announced the first successful demonstration of a new technique that improves particle beams. This demonstration could be used in future particle accelerators to potentially use the method to create better, denser particle beams , increasing the number of collisions and giving researchers a better chance to explore rare physics phenomena that help us understand our universe. The team published its findings in a recent edition of Nature .

Particle beams are made of billions of particles traveling together in groups called bunches. Condensing the particles in each beam so they are packed closely together makes it more likely that particles in colliding bunches will interact—the same way multiple people trying to get through a doorway at the same time are more likely to jostle one another than when walking through a wide-open room. Packing particles together in a beam requires something similar to what happens when you put an inflated balloon in a freezer. Cooling the gas in the balloon reduces the random motion of the molecules and causes the balloon to shrink. "Cooling" a beam reduces the random motion of the particles and makes the beam narrower and denser.

The beam particles each emit ultrafast light pulses as they pass through a special magnet called a pickup undulator (bottom right). Information about each particle's energy or trajectory error is encoded in its light pulse. The light pulses are captured, focused and tuned by various light optics. The particles then interact with their own pulses inside an identical kicker undulator (center). The interaction can be used to cool the particles or even control them, depending on the configuration of the system. Credit: Jonathan Jarvis, Fermilab Read more

The optical stochastic cooling apparatus occupies the entire 6-meter length of IOTA's long experimental straight. Designed and built by the IOTA/FAST team and industry partners, the system was recently used to achieve the world's first demonstration of OSC. Credit: Jonathan Jarvis, Fermilab Read more

A view looking downstream through the beam pipe of the IOTA ring. The optical stochastic cooling experiment occupies one of the straight sections of the IOTA ring and cools the stored beam, similar to the way radio-frequency stochastic cooling cooled antiprotons in the Recycler during the Tevatron era. Credit: Jamie Santucci, Fermilab Read more