The new electron storage ring at the center of the Advanced Photon Source (APS) has achieved another milestone: electrons are now circulating at a beam current of 25 milliamps (mA). This milestone marks the point when beamlines can begin to be verified and commissioned.

Commissioning of the storage ring continues. With beam consistently circumnavigating the 1.1 km ring at over 270,000 times per second, the process is one of gradually amping up the current. This increases the power of the X-ray beams, which will be up to 500 times brighter than before the APS Upgrade once the current is at the full 200mA.

All of the milestones reached thus far, from first turns of electrons to first stored beam to the world’s first multi-bunch swap-out injection, are indicators that the new storage ring is operating as designed. These successes are a testament to the hundreds of people who built the accelerator, several of whom were part of the construction of the original APS more than 25 years ago.

“Achieving 25mA in this new storage ring is tremendous,” said Glenn Decker, Argonne Distinguished Fellow and the associate project manager leading the realization of the new storage ring of the APS Upgrade project. “Contributing to a world-leading synchrotron facility not once, but twice has been a thrill, and I can’t heap enough praise on the team that brought this new APS to life.”

In the coming months, the APS is expected to deliver photons to the first scientific beamlines, returning them to operation. As beamlines come online over the next year, the ASD team will continue to ramp up the current until full current of 200mA is achieved.