Putting it all together: Fermilab assembles first cryomodule for LCLS-II

In February, a Fermilab team came together to witness a moment they’d looked forward to for over a year. Crew members parted the plastic sheeting at one end of a cleanroom and rolled out on narrow tracks a long string of eight accelerating cavities. It was the first cavity string for LCLS-II, which will greatly increase the power and capacity of SLAC’s Linac Coherent Light Source.

Accelerating cavities are structures that impart energy to a particle beam, and they’re the heart of the cryomodule — a major accelerator section — that Fermilab has designed and is building for LCLS-II.

“It’s a big deal. The cavity string’s all bolted up — it’s beautiful,” said SLAC scientist Marc Ross, LCLS-II cryogenics systems manager. “It’s a concrete step toward LCLS-II’s realization.”

SLAC’s LCLS-II is a powerful X-ray laser that will allow scientists to glimpse nature’s fundamental processes on an atomic level and ultrafast time scales. Today SLAC announced DOE approval of the start of construction for LCLS-II.

Since the rollout, the Fermilab team has been outfitting the cavity string with cooling equipment, instrumentation and structural support to form the cryomodule. By summer, they will have completed their first one.

“To me this is a major milestone because it shows that we can do it,” said Camille Ginsburg, the cryomodule team lead for the Fermilab LCLS-II effort. “It represents having tested all of those cavities successfully, finalized the design and put together all the assembly infrastructure that was required.”

The cryomodule is destined for LCLS-II’s new superconducting linear accelerator. Electrons speeding down the accelerator will generate an almost continuous X-ray laser beam with pulses of up to a million times per second — thousands of times faster than the current LCLS puts out. To be superconducting, the cryomodule’s cavities, made of niobium, must operate at minus 456 degrees Fahrenheit.

The linear accelerator backbone of LCLS-II comprises 37 cryomodules. Thomas Jefferson National Accelerator Facility in Virginia, another LCLS-II collaborating institution, will build 18 cryomodules of this type. Fermilab is building 17 of these cryomodules plus two that will operate at a higher frequency.

The boost from a pulsed beam to a continuous one means that the new accelerator will require much more power to operate. And with great power comes the need for great efficiency.

That’s why Fermilab scientists have, for the better part of a decade, been working on methods for building and treating cavities to be as efficient as they can be. By imparting maximum energy to the beam with minimal energy loss, efficient cavities help drive down the cost.

Last year, the Fermilab team reported a world-record quality factor, an indicator of the cavity’s efficiency in minimizing thermal losses.

“The performance of the individually tested cavities that were put into the string was far beyond anything that has been put into such a cryomodule before,” Ross said.

Fermilab also designed the cryomodule’s instrumentation to be able to handle the high power and its plumbing system to carry away heat.

“With continuous-wave operation, there’s a much higher heat load than there is with pulsed-beam acceleration, so everything has to be more robust,” said Fermilab’s Elvin Harms, who leads cryomodule testing for LCLS-II at Fermilab.

Scientists and engineers specially designed the couplers that transfer the radio-frequency power to the cavities with thicker, high-conductivity plating, for example, to carry away the high heat load.

The assembly process to this point has been painstaking, said Fermilab scientist Anna Grassellino, who is responsible for cavity preparation and testing for LCLS-II. And it promises to remain that way until the cryomodule is finally delivered to SLAC.

“Everything that’s happening now with the cryomodule assembly — every step is critical,” Grassellino said. “How you handle the parts can affect performance.”

Technicians who successfully assembled the first cavity string in the cleanroom spent two weeks carefully putting the components together. Following a protocol established at DESY in Germany and Saclay in France and borne out in tests at the Fermilab Accelerator Science and Technology facility, they moved in slow motion, since too-rapid movements would create particulates that could make their way into the cavity, degrading its operation in an accelerator.

“These techniques that seem ancillary are actually quite sophisticated,” Grassellino said. “When the cavity string was finished, it was, ‘Phew! Now it’s sealed, now it rolls out.’”

Crews are carefully installing shielding to protect the cavities from Earth’s magnetic field, which would ruin their performance; welding the cavity string to the plumbing for the super-cooled helium that will keep the cavities cold; and connecting everything structurally inside the vacuum vessel.

Cryomodule tests will begin early this summer. Fermilab and Jefferson Lab plan to move the completed cryomodules to SLAC toward the end of 2016.

“Congratulations to the entire cryomodule team here, at Jefferson Lab and at SLAC,” said Rich Stanek, Fermilab LCLS-II senior team leader. “We’re working hard to deliver cryomodules that meet or exceed specifications within the project cost and schedule.”

LCLS-II, like its predecessor LCLS, will be a DOE Office of Science User Facility.

Today Italian Prime Minister Matteo Renzi visited Fermi National Accelerator Laboratory to celebrate nearly four decades of collaboration between Fermilab and Italy. Renzi met with Fermilab Director Nigel Lockyer and Italian researchers to discuss the many contributions Italy — and Italian scientists, engineers and students — have made and continue to make to Fermilab and to particle physics research.

While at Fermilab, Renzi toured an operations center that serves as a hub for Fermilab’s neutrino experiments and a technical area where high-tech, Italian-made particle accelerator components are assembled.

“The world of research is now global and interconnected,” Renzi said, addressing a group of about 50 Italian scientists, engineers and students gathered to welcome him to the lab.

As a significant contingent on Fermilab’s CDF experiment, Italian scientists were among those who discovered the top quark in 1995. It was a major success of the relationship with the Italian National Institute of Nuclear Physics, or INFN, that started in the early 1980s.

“Our involvement is not only at the level of the physics, but also at technology, and also our industry,” said INFN Vice President for Research Antonio Masiero. “We think that, working together, we can have a mutual benefit from both institutions.”

Fermilab scientist Luciano Ristori noted that one of Italy’s — and the world’s — great physicists made an important contribution to the laboratory in nothing less than its very name.

“We are all extremely proud of the fact that this important American research laboratory is named after the great Italian Enrico Fermi,” Ristori said, addressing Prime Minister Renzi.

Prime Minister Renzi was accompanied by Italian officials including Ambassador Armando Varricchio, Deputy Minister of Economic Development Ivan Scalfarotto, and Consul General of Italy in Chicago Adriano Monti. Prominent scientists from Italy traveled to Fermilab to celebrate the occasion, including Carlo Rubbia, a Nobel Prize-winning physicist, senator-for-life of the Italian Republic and former director general of the European laboratory CERN; Antonio Masiero, INFN vice president for research; and Sergio Bertolucci, INFN coordinator for the future Deep Underground Neutrino Experiment, or DUNE, to be hosted by Fermilab.

Italian contributions to Fermilab are felt throughout the laboratory’s R&D programs. Rubbia developed the revolutionary liquid-argon detector technology behind several Fermilab neutrino experiments, including the flagship experiment DUNE, enabling researchers to study neutrino interactions in a new way.

“Fermilab helps CERN bring forward its flagship program, the LHC,” Bertolucci said. “CERN helps Fermilab to bring forward its flagship program, DUNE. And all the funding agencies, like INFN in Italy, they are working on both projects. It’s a nice synergy.”

Italian institutions have strong, ongoing partnerships with DUNE, its supporting Long-Baseline Neutrino Facility and Fermilab’s Short-Baseline Neutrino Program. Fermilab will reuse the detector for Rubbia’s ICARUS neutrino experiment, being upgraded at European laboratory CERN, which ran at the Italian Gran Sasso Laboratory from 2010-14.

“Italy is the beginning of a story, which is becoming a major American story, with neutrinos,” Rubbia said. “So I’m very happy to see how things are developing.”

Italy also plays a major role in Fermilab’s accelerator R&D. The Italian company Ettore Zanon is one of the few in the world capable of manufacturing the superconducting cavities — structures that impart energy to particle beams — designed at Fermilab for next-generation accelerators.

The superconducting magnets that will be used in Fermilab’s Mu2e experiment were designed in a fruitful collaboration between Fermilab and INFN Genoa. The partnership has yielded prototypes that can produce a magnetic field 20 times stronger than their current counterparts.

Young Italian scientists and engineers have had a major positive impact on Fermilab research, including advances made by interns who come to Fermilab through the Italian Graduate Students summer program, which has seen 400 students study at Fermilab over its 30-year history.

“You find at Fermilab that of 2,000 people, 130 are Italians,” Renzi said. “Research teams here are headed by Italians, and they are doing a great job. The important thing for us is to give Italians the opportunity not only to show the value of ‘made in Italy’ technology, but also to show the skills Italians learn in Italy. Most of these people graduated from Italian universities.”

Before departing Fermilab, Renzi met many members of Fermilab’s Italian community, including scientists, engineers, technicians and students, who will continue to strengthen the bonds between the laboratory and Italy into the future.

“There’s a special relationship between Italy and the U.S., and in particular between the science that’s taking place in Europe, at CERN, at Gran Sasso and also at Fermilab,” Lockyer said. “The Prime Minister said he could feel the passion for our science here. The future is looking great.”

View photos of the visit on Fermilab’s flickr.

View a four-minute video of highlights from the visit.

“Art of Darkness,” a new show featuring images from the Dark Energy Camera, runs through April 29, with an artists’ reception planned for March 18 from 5-7 p.m.

Imagine being able to see 8 billion light-years into space. Imagine feeling like you are near enough to another galaxy to count its spiral arms or close enough to a comet to reach out and touch it. Imagine being given a window onto the vast magnificence of the universe, without leaving Earth.

With the Dark Energy Camera, a stunning scientific instrument built and tested at the U.S. Department of Energy’s Fermilab, we can. Even better, we can capture images of the cosmos in digital quality. For the past three years, scientists have been using the camera, mounted on a telescope in the Andes Mountains in Chile, to learn more about dark energy, the mysterious force scientists think is pushing the universe apart faster and faster.

In order to do that, scientists using the camera are taking some of the most breathtaking pictures of galaxies, nebulae and other objects ever seen. And now you can see them too, as the Fermilab Art Gallery presents “Art of Darkness – Images from the Dark Energy Survey,” a new show featuring images taken with the Dark Energy Camera. The exhibit features more than a dozen dazzling photos of stars, galaxies and celestial objects (including one comet that snuck its way into frame), alongside pictures of the Cerro Tololo Inter-American Observatory, where the camera lives.

“The Dark Energy Camera is one of the best scientific instruments of its kind,” said Brian Nord, one of the Fermilab particle astrophysicists who processed many of the images that make up the show. “It not only takes amazing images of the cosmos, but it gives us valuable data to learn more about that cosmos and crack one of the main mysteries of the universe.”

The universe has been expanding since the Big Bang nearly 14 billion years ago, and that expansion is accelerating. Scientists on the Dark Energy Survey, a five-year experiment using the Dark Energy Camera, will be using these images (and millions like them) to learn more about just what is causing that expansion.

The images that make up “Art of Darkness” are the end result of a collaborative process that begins with observers and telescope operators in Chile, pointing the camera at specific parts of the night sky. Those images are digitally transferred to the National Center for Supercomputing Applications at the University of Illinois for processing. Each image taken with the camera contains about a gigabyte of information, and each picture you see on display is actually five of those images combined, each taken using a different color filter.

“It takes a lot to combine those five images into something that pops off the screen,” said Fermilab’s Martin Murphy, who collaborated on processing many of the photos in the exhibit. “But looking at the complete picture is always worth it. I’m blown away each time.”

The final result is a full-color panorama of beauty. Most of the images in “Art of Darkness” feature a particular galaxy, but look closely and you’ll see thousands of other objects. Many of the light sources in these images aren’t single stars but distant galaxies made of billions of stars each.

“I’m proud and happy to have these images from the Dark Energy Camera on display here,” said Georgia Schwender, curator of the Fermilab Art Gallery. “We often feature art inspired by science, but this is a rare example of science that already is art, and gorgeous art at that.”

“Art of Darkness” is open now and runs through April 29. The Fermilab Art Gallery is open Monday through Friday from 8 a.m. to 4:30 p.m. An artists’ reception for “Art of Darkness,” featuring scientists from the Dark Energy Survey talking about the selected images, will be held on Friday, March 18, from 5-7 p.m. The exhibit and the reception are free of charge.

The Dark Energy Survey is a collaboration of more than 400 scientists from more than 30 institutions in seven countries. Its primary instrument, the 570-megapixel Dark Energy Camera, is mounted on the 4-meter Blanco telescope at the National Optical Astronomy Observatory’s Cerro Tololo Inter-American Observatory in Chile, and its data is processed at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign.

Fermilab is America’s premier national laboratory for particle physics research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and is operated under contract by the Fermi Research Alliance LLC. Visit Fermilab’s website at www.fnal.gov, and follow Fermilab on Facebook at www.facebook.com/fermilab and on Twitter @Fermilab.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.