The throttle takes a cross-country trip to enable the laser upgrade

Today, the US Department of Energy’s Thomas Jefferson National Accelerator Facility shipped the latest new section of the accelerator it built for an upgrade of the Linac Coherent Light Source (LCLS). The accelerator section, called the cryomodule, has begun a cross-country road trip to DOE’s SLAC National Accelerator Laboratory, where it will be installed in LCLS-II, the world’s brightest X-ray laser.

“This is the culmination of seven years of work,” said Naeem Huque, the head of cost accounting who led the cryo-module efforts at Jefferson Lab. “Most of the staff from Jefferson Lab’s Superconducting Radiofrequency Institute have arrived since the start of the project, and I’m still here to say hello. We are happy to see this project come to a successful conclusion. “

LCLS-II is a project to upgrade the current Linac Coherent Light Source (LCLS), the world’s first free electron X-ray laser. The machine-generated X-ray pulses act like a powerful microscope, allowing researchers to observe chemical reactions in real time, probe materials, and more. Once completed, LCLS-II will begin its reign as the largest and brightest free-electron X-ray laser in the world.

LCLS-II will provide even better resolution than the original LCLS, which accelerated electrons to room temperature and generated 120 X-ray laser pulses per second. The upgraded machine will accelerate electrons to superconducting temperatures to generate 1 million X-ray laser pulses per second. Jefferson Lab is a key contributor to the upgrade project, providing a total of 21 cryomodules for the new superconducting portion of LCLS-II since construction began in 2013.

The superconducting accelerator that will power the upgraded machine is made up of cryomodules. The electrons whiz through the cryomodules, where they are charged with extra energy. Hence, the magnets zigzag electrons to emit their energy as X-rays. The upgraded LCLS will boast 37 cryomodules in total. Of these, 18 are from Jefferson Lab (plus three spare parts), and the rest will come from Fermilab, another key contributor.

“LCLS-II cryomodules are the highest performing cryomodules anyone has ever built,” said Joe Preble, senior team leader for the LCLS-II project at Jefferson Lab. “We have pushed the performance frontier with this type of technology and we have transformed it into a normal turnkey process “.

Jefferson Lab is a world leader in superconducting radiofrequency accelerator technologies and is home to the first large-scale SRF accelerator. While the Jefferson Lab team helped design, build, test, and ship these record-breaking cryomodules for LCLS-II, they encountered unprecedented challenges in pushing the performance of cryo-module technology.

“These ultra-high-performance cryomodules are sensitive to things we’ve never had to worry about before, like our assembly procedures, the way we handle materials, the way we build things,” Preble said.

Jefferson Lab modified its structures to accommodate cryomodules, which had a different shape and size than previous ones. Jefferson Lab staff members even devised a new way to ship the finished cryomodules, after some had broken during shipping.

“We explored a lot of different options, from renting a NASA plane to take it there, to trying to send it by train or ship,” Huque explained.

Eventually, they managed to improve safety without moving the cryo modules out of the way. Sitting on a bed of springs to avoid shock damage, Jefferson Lab’s newly shipped cryomodule will travel nearly 3,000 miles to his home in the LCLS-II linear accelerator in Menlo Park, California over the course of 72 hours.

However, Jefferson Lab’s work to improve LCLS is probably not over yet. Another upgrade to this accelerator may be on the horizon: LCLS-II HE (High Energy). If the project goes green, Jefferson Lab will build between 10 and 13 more cryomodules with a more recent procedure. Those cryomodules are expected to perform even better than the 21 they just finished.

“I think it’s one of the biggest signs that we have done really well, is that something that was already ambitious is now going even further,” said Huque. The HE upgrade, which is the culmination of the work of both the Jefferson Lab and Fermilab staff, will greatly enhance the performance capabilities of LCLS-II. “

For now, this important final delivery closes the book on Jefferson Lab’s part in providing new cryomodules for LCLS-II while research and development and prototyping for HE are already underway. Its conclusion comes thanks to the help of many.

“From purchasing staff to engineers, scientists, technicians and administrators, everyone needs to work together in the labs to accomplish this,” Preble said. “It is a great success and a demonstration of how the DOE must continue to work in building these new major projects.”