Has the black hole information paradox evaporated?

Editor’s note: This press release was originally issued by the University of Chicago on March 22, 2021.

The Midwest is leading the nation as a hub for water innovation with state-of-the-art research facilities and world-renowned researchers at the University of Chicago, Argonne National Laboratory, and Fermi National Accelerator Laboratory (Fermilab).

On World Water Day 2021, people and organizations come together to celebrate water and raise awareness of the global water crisis – focusing on how to support achievement of Sustainable Development Goal (SDG) 6: water and sanitation for all by 2030.

“To overcome the daunting challenges we face this century in providing sufficient supplies of clean water, we will need to shift from our current once-through use of water to a paradigm of water reuse and recycling. Chicagoland research institutions are leaders in developing innovative materials and technologies to enable this new approach to water (re)use,” said Seth Darling, director of the Center for Molecular Engineering at Argonne National Laboratory and Senior Scientist at the University of Chicago’s Pritzker School of Molecular Engineering (PME).

The PME integrates science and engineering to address global challenges from the molecular level up – and is the first school in the nation dedicated to the emerging field of molecular engineering.

“This region is emerging as a nexus for water innovation both nationally and globally, from the popular Third Coast Water Seminar Series to vibrant collaborative research centers like the Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center and the Israel-US Collaborative Water-Energy Research Center (CoWERC),” added Darling, who also is the director of AMEWS.

Increasing its leadership in this space, Argonne is pioneering research, discoveries, and innovations in several areas. This includes materials discovery, synthesis, characterization, and scale-up, in addition to new process technologies for systems that sense, treat, and handle water. Argonne’s mission is to pursue water science and engineering empowered by artificial intelligence (AI).

“Argonne’s ‘Water + AI’ strategy will potentially transform the water industry by offering cost-effective and socially responsible solutions to the many challenges,” said Junhong Chen, lead water strategist at Argonne and a professor of molecular engineering at the University of Chicago’s PME.

“We will accomplish this vision through partnerships with our stakeholders, including local, state and federal government, academic and national lab collaborators, industrial partners, nonprofit organizations, and regional economic development hubs,” said Chen.

Both Argonne and Fermilab, which are U.S. Department of Energy national laboratories managed by the University of Chicago, frequently work with federal agencies, other universities, and corporations on research collaborations.

Fermilab currently is working with the Metropolitan Wastewater Reclamation District of Greater Chicago, but the progress could have benefits far beyond the local area. “Fermilab is known around the world for basic research,” said Mauricio Suarez, head of the Illinois Accelerator Research Center (IARC) at Fermilab, “And now we are using the same machines that have probed the smallest constituents of matter to help create a greener planet.”

Drawing on its decades of designing and building particle accelerators for discovery, Fermilab is developing a compact, skid-mounted accelerator that can clean polluted water. The portable machine is small enough to fit in the back of a truck and works by sending a beam of electrons through the volume of water to be treated, destroying multiple contaminants simultaneously, including dyes, pathogens, pharmaceuticals, and perfluorinated compounds, which are found in the tap water of more than 15 million Americans.

A multi-tool for treating contamination, Fermilab’s compact electron accelerator will be able to treat 200,000 gallons per day – five times more than conventional technologies – and is expected to require half the power of currently available treatment options.

“By using a particle beam to clean water, we will be able to annihilate many different types of contaminants cleanly, efficiently, and cost-effectively. Water treatment is one of the many ways that particle accelerators can have a positive impact on our health and environment,” said Suarez. “We at Fermilab are proud to be able to use our particle accelerator expertise, facilities and capabilities to help solve the problem of water contamination.”

The Polsky Center for Entrepreneurship and Innovation manages the IP portfolio for all University of Chicago innovations and technologies and works to foster collaboration between laboratory scientists, engineers, students, researchers by connecting them with one another as well as with industry partners.

Today, the Department of Energy’s Fermilab shipped its final superconducting component for the new particle accelerator for the Linac Coherent Light Source II, or LCLS-II, at DOE’s SLAC National Accelerator Laboratory.

The cryomodule — the major component of the linear accelerator — is the final one required for the LCLS-II project, which will be the world’s brightest X-ray laser when complete.

“This is what we’ve been working toward for six years. Since 2014, our team has been designing, building, testing and delivering the high-performance superconducting cryomodules that will make up this forefront discovery machine,” said Rich Stanek, LCLS-II Fermilab senior team lead. “Sending it off today is the tying of the bow on our contribution effort. We are honored to be a part of LCLS-II, leveraging our expertise in superconducting acceleration technology to power the particle beam for a world-class X-ray laser. Everyone connected to the LCLS-II project should be very proud of their accomplishments.”

An upgrade of SLAC’s LCLS, which was the world’s first hard X-ray free-electron laser, LCLS-II will provide a giant leap in capability. It will fire a staggering 1 million X-ray pulses per second, up from LCLS’s 120 pulses per second. Armed with these rapid-fire rays of light, scientists using LCLS-II will be able to examine microscopic biological and chemical processes in real time and extreme detail.

The particle accelerator that provides the high-energy electrons for the LCLS-II laser will be made of 37 cryomodules, the longest of which is 12 meters (40 feet) in length. Lined up end to end like cars in a train, they form a kind of runway for the electron beam as it ramps up in energy. Eighteen of the cryomodules come from Fermilab, and 19 come from the Department of Energy’s Jefferson Lab. Both labs provided additional spares.

Once the electron beam exits the cryomodules, it is made to move rapidly from side to side through a series of undulators, emitting X-rays as it zigzags. The new undulators were designed and built by DOE’s Lawrence Berkeley National Laboratory and Argonne National Laboratory. Cornell University is also contributing components for LCLS-II.

The LCLS-II cryomodule installation is expected to be complete this spring, and LCLS-II will begin commissioning in 2022 as soon as the LCLS-II cryoplant is commissioned. LCLS-II is supported by the Department of Energy Office of Science.

“The design and construction of the LCLS-II cryomodules has been an example of true cross-institutional collaboration, bringing together three national laboratories’ expertise and capabilities in particle acceleration, superconductivity science and photon science,” said SLAC Deputy Director and LCLS-II Project Director Norbert Holtkamp. “We look forward to welcoming the final cryomodule to SLAC.”

Each cryomodule contains eight superconducting accelerator cavities, hollow structures that look like giant metallic strands of pearls. As the particle beam shoots through one cavity after the other, it picks up energy. The cryomodules, about a meter in diameter, house the cavities and allow them to be cooled to about 2 kelvins, maintaining the necessary temperatures that enable the cavities’ superconductivity.

For the last two decades, Fermilab has developed its superconducting radio-frequency, or SRF, program, which has allowed Fermilab to participate in the design, construction and testing of LCLS-II’s cutting-edge accelerator components.

“We are proud to be a key partner in the construction of this groundbreaking new light source,” said Fermilab Chief Technology Officer Alex Romanenko. “For the last two decades, DOE investment in high-energy physics has allowed Fermilab to dramatically advance R&D and develop its SRF program, leading to important breakthroughs in SRF cavities’ efficiency, thanks to discoveries such as nitrogen doping and fast cooling methods for reducing trapped magnetic fields. These improvements contributed to LCLS-II’s world-leading cryomodules.”

The LCLS-II SRF cryomodule design is a modification of a type developed at the DESY laboratory in Germany. Fermilab’s further R&D in the area of the preparation of superconducting surfaces drew record-setting performance from the accelerator cavities, making them highly energy-efficient while accelerating beam. Work is already underway on the next generation of cryomodules for a future high-energy upgrade to LCLS-II.

“Fermilab and Jefferson Lab’s leadership in SRF made them the perfect partners to engage in the design and construction of the LCLS-II accelerator,” said the DOE Bay Area Site Office Deputy Manager Hanley Lee, the Federal Project Director for the effort. “SLAC’s new X-ray laser would not be the advanced machine we expect it to be without these cutting-edge cryomodules. LCLS-II will be an unprecedented tool for discovery, shining a bright light on hidden processes in nature that could hold keys for improving our health, environment and security. We could not build it without the diverse expertise of researchers from the broad range of fields that came together as part of this extraordinary project.”

Fermilab Director Nigel Lockyer agrees that, in the success of LCLS-II cryomodules, collaboration was key.

“The LCLS-II project is a wonderful partnership of the DOE labs’ strengths,” Lockyer said. “Capitalizing on the accelerator science and technology developed at Fermilab for investigating the basic building blocks of matter, we now apply it to LCLS-II so we can explore new scientific territory. LCLS-II is a testament to the cooperative scientific endeavor.”

Learn more about the LCLS-II cryomodules and project.

Fermilab is America’s premier national laboratory for particle physics and accelerator research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance LLC, a joint partnership between the University of Chicago and the Universities Research Association, Inc. Visit Fermilab’s website at www.fnal.gov and follow us on Twitter at @Fermilab.

Fermilab is supported by the Office of Science of the U.S. Department of Energy. The 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 energy.gov/science.

The detected intensity from two coherent point-like light sources depends on their relative positions. It is a well-known phenomenon called optical interference. In general, the intensity can range from zero (destructive interference) to some maximum value (constructive interference).

Consider two high-energy electrons circulating in a particle storage ring, such as the Integrable Optics Test Accelerator at Fermilab. As it was discovered in 1947, when high-energy electrons are forced to travel in a curved path, they emit light, known as synchrotron radiation. If we record the detected synchrotron light intensity at every revolution in a storage ring, we will observe slight fluctuations of its magnitude from turn to turn because the relative positions of the two electrons change.

The IOTA storage ring, hosted by the Department of Energy’s Fermilab, can store a billion electrons. Just as in the two-electron case, the turn-to-turn fluctuations of the billion electrons’ radiation intensity still exist, and for the same reasons. The fluctuations are very small, below 0.1% (root-mean-square). Still, our research group was able to measure them, and we showed that this information can be used to gain insights into the electron beam’s properties, such as its dimensions and divergence — a measure of spread in directions of motion of the electrons in the beam.

The proof-of-principle measurements in IOTA were performed in the near-infrared synchrotron light spectrum range. The sensitivity of this noninvasive method for determining the electron beam properties improves when synchrotron light of shorter wavelength and higher brightness is used. This means it may particularly benefit existing state-of-the-art and next-generation low-emittance high-brightness ultraviolet and X-ray synchrotron light sources, where noninvasive electron beam characterization is difficult.

For instance, we think this method could measure transverse beam sizes on the order of 10 microns in the Advanced Photon Source Upgrade at Argonne National Laboratory, by using the turn-to-turn fluctuations in the X-ray synchrotron light. This is an important step in making tighter electron beams, which in turn generate brighter X-rays. With brighter X-rays, researchers will be able to accelerate research in chemistry, materials science and medicine, including COVID-19 research.

A paper on this result will be published in Physical Review Letters. An expanded companion paper will be published in Physical Review Accelerators and Beams. Corresponding papers “Transverse beam emittance measurement by undulator radiation power noise” and “Measurements of undulator radiation power noise and comparison with ab initio calculations” were published on arXiv.

Research at IOTA is supported by the DOE Office of Science.

The 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, visit science.energy.gov.

Ihar Lobach is a physics graduate student at the University of Chicago conducting research at Fermilab’s Integrable Optics Test Accelerator. His academic advisor is Fermilab scientist and University of Chicago Professor Sergei Nagaitsev, and his Fermilab research supervisor is Fermilab scientist Giulio Stancari.