November 2, 2024

A Chilling Feat: Superconducting X-Ray Laser Reaches Operating Temperature Colder Than Outer Space

Considering that the Department of Energys SLAC National Accelerator Laboratory powered up its “linac” half a century ago, the 2-mile-long particle accelerator has driven a big number of effective research study programs in particle physics, accelerator advancement, and X-ray science. For that to happen, teams got rid of part of the old copper accelerator and installed a series of 37 cryogenic accelerator modules, which house pearl-like strings of niobium metal cavities.” Unlike the copper accelerator powering LCLS, which runs at ambient temperature level, the LCLS-II superconducting accelerator runs at 2 kelvins, just about 4 degrees Fahrenheit above outright no, the lowest possible temperature,” stated Eric Fauve, director of the Cryogenic Division at SLAC. The SLAC Cryogenics team has actually worked on website throughout the pandemic to set up and cool and commission the cryogenic system down the accelerator in record time.”
In addition to a new accelerator and a cryoplant, the project required other innovative parts, including a new electron source and two new strings of undulator magnets that can produce both “difficult” and “soft” X-rays.

SLACs linac at daybreak, looking east. Given that the Department of Energys SLAC National Accelerator Laboratory powered up its “linac” half a century back, the 2-mile-long particle accelerator has actually driven a big number of successful research programs in particle physics, accelerator advancement, and X-ray science. Now, the historical particle highway brand-new remodeling will pave the method for more groundbreaking research study. Credit: Olivier Bonin/SLAC National Accelerator Laboratory.
” In simply a few hours, LCLS-II will produce more X-ray pulses than the existing laser has actually produced in its entire lifetime,” says Mike Dunne, director of LCLS. “Data that as soon as might have taken months to collect could be produced in minutes. It will take X-ray science to the next level, paving the method for an entire new series of research studies and advancing our capability to establish advanced technologies to attend to some of the most profound challenges facing our society.”
With these sophisticated new abilities, scientists can take a look at the information of complicated materials with unmatched resolution to drive new types of computing and communications; reveal unusual and short lived chemical events to teach us how to develop more sustainable markets and clean energy technologies; examine how biological molecules perform lifes functions to establish new types of pharmaceuticals; and peer into the strange world of quantum mechanics by straight measuring the movements of private atoms.
A chilling task
LCLS, the worlds very first hard X-ray free-electron laser (XFEL), produced its very first light in April 2009, creating X-ray pulses a billion times brighter than anything that had come in the past. It speeds up electrons through a copper pipe at room temperature, which limits its rate to 120 X-ray pulses per second.

In 2013, SLAC launched the LCLS-II upgrade project to boost that rate to a million pulses and make the X-ray laser countless times more powerful. For that to happen, crews removed part of the old copper accelerator and set up a series of 37 cryogenic accelerator modules, which house pearl-like strings of niobium metal cavities. These are surrounded by three nested layers of cooling devices, and each succeeding layer lowers the temperature level up until it reaches almost outright no– a condition at which the niobium cavities end up being superconducting.
” Unlike the copper accelerator powering LCLS, which operates at ambient temperature, the LCLS-II superconducting accelerator runs at 2 kelvins, just about 4 degrees Fahrenheit above absolute no, the least expensive possible temperature,” said Eric Fauve, director of the Cryogenic Division at SLAC. “To reach this temperature, the linac is geared up with two world-class helium cryoplants, making SLAC among the substantial cryogenic landmarks in the U.S. and on the world. The SLAC Cryogenics team has actually dealt with website throughout the pandemic to install and cool and commission the cryogenic system down the accelerator in record time.”
Cutaway picture of a cryomodule. Each big metal cylinder contains layers of insulation and cooling equipment, in addition to the cavities that will speed up electrons. The cryomodules are fed liquid helium from an aboveground cooling plant. Microwaves reach the cryomodules through waveguides linked to a system of solid-state amplifiers. Credit: Greg Stewart/SLAC National Accelerator Laboratory
One of these cryoplants, built particularly for LCLS-II, cools helium gas from room temperature all the way to its liquid stage at simply a couple of degrees above absolute zero, offering the coolant for the accelerator.
On April 15, the brand-new accelerator reached its last temperature level of 2 K for the very first time and today, May 10, the accelerator is all set for initial operations.
” The cooldown was a critical procedure and had to be done very carefully to avoid damaging the cryomodules,” said Andrew Burrill, director of SLACs Accelerator Directorate. “Were thrilled that weve reached this milestone and can now focus on switching on the X-ray laser.”
The linac is equipped with 2 world-class helium cryoplants. Among these cryoplants, developed particularly for LCLS-II, cools helium gas from space temperature all the way to its liquid stage at just a couple of degrees above outright zero, providing the coolant for the accelerator. Credit: Greg Stewart/SLAC National Accelerator Laboratory
Bringing it to life
In addition to a brand-new accelerator and a cryoplant, the job needed other cutting-edge parts, consisting of a brand-new electron source and two new strings of undulator magnets that can generate both “tough” and “soft” X-rays. Soft X-rays can catch how energy streams between atoms and particles, tracking chemistry in action and offering insights into brand-new energy innovations.
Jefferson Lab, Fermilab and SLAC pooled their know-how for research study and advancement on cryomodules. After building the cryomodules, Fermilab and Jefferson Lab checked each one thoroughly prior to the vessels were packed and delivered to SLAC by truck. The Jefferson Lab team also created and helped obtain the aspects of the cryoplants.
Fermilab cryomodule F3.9-02, installed inside of LCLS-II. Credit: Jacqueline Orrell/SLAC National Accelerator Laboratory
” The LCLS-II project required years of effort from big teams of service technicians, engineers, and researchers from five different DOE laboratories throughout the U.S. and numerous coworkers from around the globe,” says Norbert Holtkamp, SLAC deputy director and the task director for LCLS-II. “We couldnt have made it to where we are now without these continuous collaborations and the competence and commitment of our collaborators.”
Toward first X-rays
Now that the cavities have actually been cooled, the next step is to pump them with more than a megawatt of microwave power to speed up the electron beam from the brand-new source. If whatever is aligned just right– to within a portion of the width of a human hair– the electrons will produce the worlds most powerful bursts of X-rays.
This is the very same procedure that LCLS uses to generate X-rays. Nevertheless, since LCLS-II uses superconducting cavities instead of warm copper cavities based upon 60-year-old technology, it can deliver up to a million pulses per second, 10,000 times the number of X-ray pulses for the very same power bill.
Now that the cavities have actually been cooled, the next step is to pump them with more than a megawatt of microwave power to accelerate the electron beam from the brand-new source. Electrons going through the cavities will draw energy from the microwaves so that by the time the electrons have actually travelled through all 37 cryomodules, theyll be moving close to the speed of light. Credit: Greg Stewart/SLAC National Accelerator Laboratory
Once LCLS-II produces its very first X-rays, which is expected to occur later on this year, both X-ray lasers will operate in parallel, allowing scientists to perform experiments over a larger energy range, capture in-depth pictures of ultrafast processes, probe delicate samples and collect more data in less time, increasing the variety of experiments that can be performed. It will greatly broaden the clinical reach of the facility, enabling scientists from across the country and all over the world to pursue the most compelling research concepts.
This task is supported by DOEs Office of Science. LCLS is a DOE Office of Science user facility.

Credit: SLAC National Accelerator Laboratory
The new facility, LCLS-II, will quickly hone our view of how nature deals with ultrasmall, ultrafast scales, affecting everything from quantum devices to clean energy.
Nestled 30 feet underground in Menlo Park, California, a half-mile-long stretch of tunnel is now cooler than the majority of deep space. It houses a new superconducting particle accelerator, part of an upgrade job to the Linac Coherent Light Source (LCLS) X-ray free-electron laser at the Department of Energy (DOE)s SLAC National Accelerator Laboratory
Teams effectively cooled the accelerator to minus 456 degrees Fahrenheit– or 2 kelvins– a temperature at which it ends up being superconducting and can improve electrons to high energies with almost zero energy lost while doing so. It is among the last milestones before LCLS-II will produce X-ray pulses that are 10,000 times brighter, usually, than those of LCLS and that get here as much as a million times per 2nd– a world record for todays most effective X-ray lights.