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Stem cell growth, required for kernel development, is controlled in corn by a set of genes called CLEs. But how these genes change the corn is complicated. Using CRISPR genome editing, CSHL researchers found they could change kernel yield and ear size by fine-tuning the activity of one of the CLE genes, ZmCLE7. In the image: an unmodified corn cob with normal ZmCLE7 gene activity (1) is packed with regular rows of kernels. Shutting off ZmCLE7 (2) shortened the cob, disrupted row patterns, and lowered kernel yield. However, decreasing the same gene’s activity (3) led to an increase in kernel yield, while increasing the gene’s activity (4) decreased the kernel yield. Jackson Lab/CSHL 2021

By Daniel Dunaief

The current signal works, but not as well as it might. No signal makes everything worse. Something in the middle, with a weak signal, is just right.

By using the gene-editing tool CRISPR, Cold Spring Harbor Laboratory Professor Dave Jackson has fine-tuned a developmental signal for maize, or corn, producing ears that have 15 to 26 percent more kernels. 

Dave Jackson. Photo from CSHL

Working with postdoctoral fellow Lei Liu in his lab, and Madelaine Bartlett, who is an Associate Professor at the University of Massachusetts Amherst, Jackson and his collaborators published their work earlier this week in the prestigious journal Nature Plants.

Jackson calls the ideal weakening of the CLE7 gene in the maize genome the “Goldilocks spot.” He also created a null allele (a nonfunctional variant of a gene caused by a genetic mutation) of a newly identified, partially redundant compensating CLE gene.

Indeed, the CLE7 gene is involved in a process that slows the growth of stem cells, which, in development, are cells that can become any type of cell. Jackson also mutated another CLE gene, CLE1E5.

Several members of the plant community praised the work, suggesting that it could lead to important advances with corn and other crops and might provide the kind of agricultural and technological tools that, down the road, reduce food shortages, particularly in developing nations.

“This paper provides the first example of using CRISPR to alter promoters in cereal crops,” Cristobal Uauy, Professor and Group Leader at the John Innes Centre in the United Kingdom, explained in an email. “The research is really fascinating and will be very impactful.”

While using CRISPR (whose co-creators won the Nobel Prize in Chemistry in October) has worked with tomatoes, the fact that it is possible and successful in cereal “means that it opens a new approach for the crops that provide over 60% of the world’s calories,” Uauy continued.

Uauy said he is following a similar approach in wheat, although for different target genes.

Recognizing the need to provide a subtle tweaking of the genes involved in the growth of corn that enabled this result, Uauy explained that the variation in these crops does not come from an on/off switch or a black and white trait, but rather from a gradient.

In Jackson’s research, turning off the CLE7 gene reduced the size of the cob and the overall amount of corn. Similarly, increasing the activity of that gene also reduced the yield. By lowering the gene’s activity, Jackson and his colleagues generated more kernels that were less rounded, narrower and deeper.

Uauy said that the plant genetics community will likely be intrigued by the methods, the biology uncovered and the possibility to use this approach to improve yield in cereals.

“I expect many researchers and breeders will be excited to read this paper,” he wrote.

In potentially extending this approach to other desirable characteristics, Uauy cautioned that multiple genes control traits such as drought, flood or disease resistance, which would mean that changes in the promoter of a few genes would likely improve these other traits.

“This approach will definitely have a huge role to play going forward, but it is important to state that some traits will still remain difficult to improve,” Uauy explained.

Jackson believes gene editing has considerable agricultural potential.

“The prospect of using CRISPR to improve agriculture will be a revolution,” Jackson said.

Other scientists recognized the benefits of fine-tuning gene expression.

“The most used type/ thought of mutation is deletion and therefore applied for gene knockout,” Kate Creasey Krainer, president and founder of Grow More Foundation, explained in an email. “Gene modulation is not what you expect.”

While Jackson said he was pleased with the results this time, he plans to continue to refine this technique, looking for smaller regions in the promoters of this gene as well as in other genes.

“The approach we used so far is a little like a hammer,” Jackson said. “We hope to go in with more of a scalpel to mutate specific regions of the promoters.”

Creasey Krainer, whose foundation hopes to develop capacity-building scientific resources in developing countries, believes this approach could save decades in creating viable crops to enhance food yield.

She wrote that this is “amazing and could be the green revolution for orphan staple crops.”

In the United States, the Food and Drug Administration is currently debating whether to classify food as a genetically modified organism, or GMO, if a food producer used CRISPR to alter one or more of its ingredients, rather than using genes from other species to enhance a particular trait.

To be sure, the corn Jackson used as a part of his research isn’t the same line as the elite breeding stock that the major agricultural businesses use to produce food and feedstock. In fact, the varieties they used were a part of breeding programs 20 or more years ago. It’s unclear what effect, if any, such gene editing changes might have on those crops, which companies have maximized for yield.

Nonetheless, as a proof of concept, the research Jackson’s team conducted will open the door to additional scientific efforts and, down the road, to agricultural opportunities.

“There will undoubtedly be equivalent regions which can be engineered in a whole set of crops,” Uauy wrote. “We are pursuing other genes using this methodology and are very excited by the prospect it holds to improve crop yields across diverse environments.”

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Photo from BNL

COVID-19 needs no introduction. Scientists fighting it do.

John Hill leads the COVID-19 Science and Technology Working Group at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. He also represents Brookhaven in a DOE consortium—the National Virtual Biotechnology Laboratory—which includes all 17 national laboratories working to address key challenges in responding to COVID-19.

The COVID-19 working group Hill leads at Brookhaven comprises experts in biology, nanoscience, computation, and other areas of science. They and their collaborators are leveraging world-class capabilities to study the structure of viral components, narrow the search for drugs, track research efforts, model the disease’s spread, and more.

Hill will give a virtual talk about the impacts of Brookhaven’s multifaceted COVID-19 research on Thursday, Feb. 25. The event, held from 6:30 to 7:30 p.m., will also include an interactive Q&A session, when audience members can submit questions for Hill and two of his colleagues:

How to join the event—and ask a question

This event will stream live on Twitter, Facebook, and YouTube. During the Q&A session, audience members can ask questions, using those streaming platforms’ chat functions.

You don’t need an account with Twitter, Facebook, or Google to watch the talk. You do need an account to ask questions via chat. Or you can email questions to [email protected] before the talk.

About the speakers

John Hill is the Deputy Associate Laboratory Director for Energy and Photon Sciences, and Director of the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science User Facility at Brookhaven Lab. He previously served as leader for the X-ray Scattering group in the Lab’s Condensed Matter Physics and Materials Science Department. He is recognized as a world leader in x-ray scattering techniques for studying condensed matter systems.

Hill joined Brookhaven Lab as a postdoc in 1992, after earning a Ph.D. in physics from the Massachusetts Institute of Technology. He earned a bachelor’s degree in physics from Imperial College in London in 1986.

Kerstin Kleese van Dam is Director of the Computational Science Initiative (CSI) at Brookhaven Lab. CSI leverages computational science expertise and investments across multiple programs to tackle big-data challenges at the frontiers of scientific discovery. Kleese van Dam and collaborators at Brookhaven and Stony Brook University have applied simulations, machine learning, and other artificial intelligence tools in the fight against COVID-19.

Sean McSweeney is the Director of the Laboratory for BioMolecular Structure (LBMS) at Brookhaven. LBMS is home to state-of-the-art cryo-electron microscopes and other equipment for researchers to study the building blocks of all living organisms. Most of the data McSweeney and his group collected for COVID-19 research was done at NSLS-II.

Brookhaven National Laboratory is supported by the U.S. Department of Energy’s 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 https://energy.gov/science.

Follow @BrookhavenLab on Twitter or find us on Facebook.

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The cover of the book depicts split images of a 13th century window at Notre Dame de Paris, and the Compacy Moon Solenoid of the Large Hedron Collider, 2004

Reviewed by Elizabeth Kahn Kaplan

St. James resident Philip Palmedo’s latest book, Deep Affinities: Art and Science, skillfully develops the premise that close observation and representation of the natural world, driven by “careful curiosity,” was the starting point of both art and science in the far distant past, and that their deep relationship — affinity — continues to the present.  

Ironstone hand ax, 600,000 BP

A fascinating early chapter includes a reference to a work of sculpture dating from at least 50,000 BP (Before the Present), before Homo sapiens came to Europe. “A small stone that resembled a bird was collected by a Neanderthal and then modified to be more realistic. A hole was drilled for the eye, and the shape of the beak and tail was smoothed.”  Palmedo offers evidence that this object and other stone carvings, as well as cave drawings created by our earliest ancestors, indicate that the origins of science and the starting point of art began with careful curiosity leading to observation of the natural world — the same influences that inspire the work of scientists and artists today. 

As far back as 600,000 BP an aesthetic sensibility and a scientific instinct appeared in an ironstone hand ax found in South Africa; the early human who shaped it was concerned with form as well as function — with symmetry and balance, fundamental to both art and science. 

Palmedo expands upon symmetry and balance as essential qualities in nature and in art. He calls attention to nature’s fractals — similar patterns that recur at progressively smaller scales. An example in nature is the branch of a fern with same-shaped pairs of leaves becoming progressively smaller as they progress up the stem. An example in art is a Japanese woodblock print known as The Great Wave, in which the artist, Katsushika Hokosai, incorporated the concept of fractals, painting smaller yet otherwise identical waves with identical yet smaller and smaller boats upon them. “Fractal patterns are broadly appealing” in their balance and symmetry. 

The mathematically defined geometric shapes of Pablo Picasso’s Les Demoiselles d’Avignon (1907) abound in nature as well as art. A cutaway of a nautilus shell reveals a logarithmic spiral; Robert Smithson’s Spiral Jetty (1970) in Utah echoes the Whirlpool Galaxy in outer space. 

‘The Great Wave’ by Katsushika Hokosai, 1830-32

The commonality of the circle in science and its aesthetic significance is spotlighted in the book’s cover art: a split image of the 13th century circular window in the north transept of Notre Dame de Paris is juxtaposed with a split image of the 21st century circular particle detector at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN), near Geneva — the largest, most costly machine in the world, the most powerful particle accelerator, consisting of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. 

Pairing images of the stained-glass window and this powerful machine is a brilliant visible support of Palmedo’s theme. Scientist and mathematician Albert Einstein was developing his breakthrough theory of the relativity of space and time during the same decades that Picasso and Georges Braque were developing their major breakthrough in art — Cubism — while Marcel Duchamp was illustrating movement through space in his Nude Descending A Staircase (1912). 

Einstein said, “The greatest scientists are artists as well:” one might well say that “The greatest artists are scientists as well,” and cite only two of many:  Leonardo da Vinci’s studies of anatomy, or Johannes Vermeer’s experiments with the camera obscura. 

The cover of the book depicts split images of a 13th century window at Notre Dame de Paris, and the Compacy Moon Solenoid of the Large Hedron Collider, 2004

In recent decades, two New York art museums spotlighted works of art linked directly to science. In 2004, The Museum of Modern Art displayed the world’s largest jet-engine fan blade, manufactured by General Electric, “rising from a narrow black base, twisting and expanding into a fan shape while undulating slightly into a lean S-curve. In its clear abstraction it could have been inspired by Constantin Brancusi, connecting mathematics, efficiency, and art.” 

Then, in 2019, The Metropolitan Museum of Art’s exhibit, “Making Marvels: Science and Splendor at the Courts of Europe,” spotlighted, among many other magnificent objects, a rotating mechanical celestial globe of partially gilded silver perched atop a silver horse, created by Gerhard Emmoser for the Holy Roman Emperor Rudolf II in 1579. Writes Palmedo, “The intersection of art, technology, outpouring of creativity and learning, gave rise to exquisite objects that were at once beautiful works of art and technological wonders.” 

Palmedo’s undergraduate studies of Art History and Physics and a Ph.D. in Nuclear Engineering, followed by a lifetime of professional and personal activism in both fields, support this current work — a logical progression following the author’s beautifully written and illustrated earlier books. 

The Experience of Modern Sculpture: A Guide to Enjoying Works of the Past 100 Years (2015) followed four books about the lives and work of noted contemporary American sculptors — Richard McDermott Miller (1998); Bill Barrett (2003); Joel Perlman (2006) and Lin Emery (2012.) In Deep Affinities: Art and Science, Palmedo has expanded his range, from the contemporary art scene back to the distant past.  

Like Palmedo’s previous books, Deep Affinities is printed on thick glossy stock enriched by more than 100 color illustrations. Palmedo leaps into his subject, proves his thesis with definitive clarity, and expands our thinking about artists and scientists as equal partners in their achievements. It is also, with its carefully chosen and extensive bibliography, a worthy addition to the bookshelves of both. 

The book is available at Amazon.com and from the publisher, Abbeville Press.  

 

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Feinstein Institutes’ Drs. Kevin Tracey and Christina Brennan break down the current COVID-19 clinical trials and treatments. Photo courtesy of The Feinstein Institutes for Medical Research

By Daniel Dunaief

In a collaboration between Cold Spring Harbor Laboratory and Northwell Health’s Feinstein Institutes for Medical Research, doctors and researchers are seeking patients with mild to moderate symptoms of COVID-19 for an at-home, over-the-counter treatment.

The two-week trial, which will include 84 people who are 18 years old and older, will use a high, but safe dose of Famotidine, or PEPCID, in a double-blind study. That means that some of the participants will receive a placebo while others will get the Famotidine.

Volunteers will receive the dosage of the medicine or the placebo at home and will also get equipment such as pulse oximeters, which measure the oxygen in their blood, and spirometers, which measure the amount of air in their lungs. They will also receive a scale, a thermometer, a fitness tracker and an iPad.

Dr. Christina Brennan. Photo courtesy of The Feinstein Institutes for Medical Research

Northwell Health will send a certified phlebotomist — someone licensed to draw blood — to the participants’ homes to collect blood samples on the first, 7th, 14th, and 28th day of the study.

The study is the first time CSHL and Northwell Health have designed a virtual clinical trial that connects these two institutions.

“What is very powerful with our work with Cold Spring Harbor Laboratory is the ability to do a virtual trial and utilize patient-recorded outcome measures,” said Christina Brennan, a co-investigator on the study and Vice President for Clinical Research for Northwell Health. “I’m thrilled that we’re doing this type of virtual trial. It’s very patient-centric.”

While reports about the potential benefits of Famotidine have circulated around the country over the last year, this study will provide a data-driven analysis.

“If we study this in the outpatient population, then we might have an opportunity to see if [Famotidine] really does play a role in the reduction of the immune overreaction,” Brennan said.

At this point, researchers believe the drug may help reduce the so-called cytokine storm, in which the immune system becomes so active that it starts attacking healthy cells, potentially causing damage to organs and systems.

In an email, Principal Investigator Tobias Janowitz, Assistant Professor and Cancer Center Member at Cold Spring Harbor Laboratory, wrote that “there are some retrospective cohort studies” that suggest this treatment might work, although “not all studies agree on this point.”

In the event that a trial participant developed more severe symptoms, Janowitz said the collaborators would escalate the care plan appropriately, which could include interrupting the use of the medication.

In addition to Janowitz, the medical team includes Sandeep Nadella, gastroenterologist at Northwell, and Joseph Conigliaro, Professor of the Feinstein Institutes for Medical Research.

Janowitz said he does not know how any changes in the virus could affect the response to famotidine.

In the trial, volunteers will receive 80 milligrams of famotidine three times a day.

The dosage of famotidine that people typically take for gastric difficulties is about 20 milligrams. The larger amount per day meant that the researchers had to get Food and Drug Administration approval for an Investigational New Drug.

“This has gone through the eyes of the highest regulatory review,” Brennan said. “We were given the green light to begin recruitment, which we did on January 13th.”

Volunteers are eligible to join the study if they have symptoms for one to seven days prior to entering the trial and have tested positive for the virus within 72 hours.

Potential volunteers will not be allowed in the trial if they have had other medications targeting COVID-19, if they have already used Famotidine in the past 30 days for any reason, if they have severe COVID that requires hospitalization, have a history of Stage 3 severe chronic disease, or if they are immunocompromised by the treatment of other conditions.

Brennan said Northwell has been actively engaged in treatment trials since the surge of thousands of patients throughout 2020.

Northwell participated in trials for remdesivir and also provided the steroid dexamethasone to some of its patients. The hospital system transfused over 650 patients with convalescent plasma. Northwell is also infusing up to 80 patients a day with monoclonal antibodies. The hospital system has an outpatient remdesivir trial.

“Based on all our experience we’ve had for almost a year, we are continuously meeting and deciding what’s the best treatment we have available today for patients,” Brennan said.

Janowitz hopes this trial serves as a model for other virtual clinical trials and is already exploring several potential follow up studies.

Brennan said the best way to recruit patients is to have the support of local physicians and providers. 

People interested in participating in the trial can send an email to [email protected] or call 516-881-7067.

When the study concludes, the researchers will analyze the data and are “aware that information on potential treatments for COVID-19, no matter if the data show that a drug works or does not work, should be made available to the community swiftly,” Janowitz wrote in an email.

The decision to test this medicine as a potential treatment for COVID-19 arose out of a conversation between Director of the Cold Spring Harbor Laboratory Cancer Center Dave Tuveson and CEO of the Feinstein Institute Kevin Tracey.

“I got involved because I proposed and developed the quantitative symptom tracking,” Janowitz explained.

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Weisen Shen. Photo by John Griffen/SBU

By Daniel Dunaief

Like so many others during the pandemic, Weisen Shen has had to pivot in his job.

An Assistant Professor in the Department of Geosciences at Stony Brook University, Shen has historically focused his efforts on understanding the geothermal heat flux, or the movement of heat from the core of the Earth, in Antarctica.

Constrained by travel restrictions created by the COVID-19 pandemic, Shen has decided to put his 180 seismometers to good use on Long Island.

“We have seismometers that stay in the basement of our building,” Shen said. “We can’t use them in Antarctica because of the travel ban and other complexities, and we want to make use of them in our community to understand the geology of Long Island.”

Shen is looking for students who might be interested in geology and who might like to plant a seismometer in their backyard, gathering information about how the flow of seismic waves deep beneath their homes and backyards reveals details about the structure, temperature and composition of the land miles below the surface.

Shen, who lives in Syosset, installed a seismometer in his own backyard, which has allowed him to see the signal from the local train station in Sayville. “We seek help from [the local community] to allow us to deploy a seismometer in their back or front yard for a month or so,” Shen said.

Planting a seismometer would involve digging a 15 centimeter by 15 centimeter hole that is 5 inches deep. Shen and his team would cover it. The seismometer wouldn’t need local electricity because it has a lithium battery. 

After about a month, the scientists would dig it out, put dirt back in, and return the backyard to the way it looked prior to taking these measurements.

The machine doesn’t make any noise and does not pick up any sounds from inside people’s homes.

The signal will contribute “to our understanding of the Earth,” Shen explained, including details about the crustal and mantle structure, seismic activities, and the Earth’s vibrations due to civil activities such as the rumbling of trains.

Shen is “more than happy to share data” with the people who host his seismometers. He also expects to produce a research paper based on his studies from Long Island.

He is charging the batteries and testing the instruments and plans to plant them in the field as early as the end of February.

People who would like to participate can reach out to Shen by sending him an email at [email protected]. Please include “Volunteer Long Island Imager” in the subject line.

Recent Antarctica Studies

While Shen is focusing his geothermal expertise on Long Island, he hasn’t abandoned or ignored Antarctica, a region he has focused research efforts on because of the vulnerability of the ice sheet amid climate change. He is also interested in the geothermal structure in the area, which reveals information about its geology and tectonics, which remain mysteries residing below the ice. 

Grounded during the pandemic, Shen spent several months gathering and analyzing considerable available data, hoping to understand what happens deep below the frozen surface.

“We are trying to analyze so-called ‘legacy data’ that has been collected over the past two decades,” he said.

On a fundamental level, Shen is trying to quantify how much heat is coming out through the crust, which includes heat coming from the deeper earth in the mantle and the core as well as within the crust.

Traveling beneath the oceans towards the center of the Earth, which would be considerably hotter and more difficult than 19th century author Jules Verne’s fantastic fictional voyages, would expose people to temperatures that increase, on average, about 10 to 30 degrees celsius per kilometer.

Some of the heat comes from the way the planet formed. In addition, unstable isotopes of potassium, uranium and thorium release heat as they decay, which mostly happens within the Earth’s crust. 

In areas with large ice sheets sitting on top of the land, the geothermal heat can melt some of that ice, creating a layer of water that accelerates the ice sheet movement. Indeed, pulling an ice cube across dry ground takes more energy than dragging that same cube across a wet surface.

Moving ice more rapidly towards the periphery will increase melting which, coupled with climate change, could increase the amount of water in Antarctica, particularly in the western region.

Comparing the two ice melting effects, Shen believes global warming, which is more rapid and has shorter term outcomes, plays a more important role in changing the liquid characteristics of Antarctica than geothermal heating, which is longer term.

In collecting available legacy data, Shen analyzed information from the entire western part of Antarctica, as well as parts of the central and eastern regions.

Using a measure of the geothermal heat flux, Shen found some unexpected results, particularly on Thwaites Glacier, beneath which he found a large area with elevated geothermal heat flux. 

Studying geomagnetic data, he compared their results with the results from geomagnetically derived results. In the future, he will combine the two different methods to improve the assessment. 

In a publication last summer in Geophysical Research Letters, Shen presented a new map of the geothermal heat flux for Antarctica with a new resolution of 100 kilometers by 100 kilometers, which is a much higher resolution than earlier studies, which are typically done at 600 kilometer by 600 kilometer ranges.

In West Antarctica, he found a more modest heat flux, despite the area being more tectonically active.

Finally, a major take of the paper, Shen said, is that the Thwaites glacier has a high geothermal heat flux, which could explain why the ice moves more rapidly and readily.

As for his future work, in addition to exploring the seismology of Long Island, Shen said he would pursue his National Science Foundation grant to look for additional water in the boundary between the ice sheet and the mantle.

He is working on “using high frequency seismic records to look for data,” he said.

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The first place Great Neck South High School team members, pictured from left, Matthew Tsui, David Wang, Anthony Zhan (team captain), Jansen Wong, Bradley He, and coach James Tuglio pose for a photo after winning first place in 2020.

Great Neck South High School earned the top spot in the Long Island Regional High School Science Bowl hosted by the U.S. Department of Energy’s Brookhaven National Laboratory on Saturday, Jan. 30.  

The winning team faced off virtually against 23 other teams from a total of 18 high schools in the regional competition, part of the DOE National Science Bowl® (NSB). The students tested their knowledge in areas including biology, chemistry, earth and space science, energy, mathematics and physics in the fast-paced question-and-answer tournament.  

The win marks the second consecutive year team members Anthony Zhan, Bradley He, Matthew Tsui, David Wang, and Jansen Wong secured first place for their school. 

“By having the same team for both years, you grow a lot as a team,” said team captain Zhan. “I think a big factor in our success was our team chemistry. We play really well as a team and as a group of friends.” 

For the first time since its establishment in 1991, the competition had to pivot to a virtual format. Teams competed remotely via video chat rooms ran by volunteer moderators, judges, and scorekeepers. After three preliminary rounds, 16 teams advanced to elimination rounds, in which Great Neck South outlasted the rest.

Mary Alexis Pace, coach to second place team The Wheatley School, acknowledged Brookhaven’s Office of Educational Programs (OEP) and volunteers for their hard work in organizing the regional competition.

“I am thankful Brookhaven Lab was able to make this competition work in such a strange year,” Pace said. “I know I speak for all of my students when I say that we truly appreciate the efforts that go into making this event happen.” 

Great Neck South will join the top teams from regional science bowls around the country in the National Science Bowl®, which will be held virtually throughout April and May 2021.  

Second place: Wheatley School–Viraj Jayan, Freddy Lin, Victor Li, and Avinash Reddy 

Third place: Ward Melville High School (team one)–Neal Carpino, Gabriel Choi, Matthew Chen, Ivan Ge, and Prisha Singhal 

Fourth place: Plainegde Senior High School–Aidan Andersen, Luke Andersen, Joseph Devlin, Matthew Garcia, and Tyler Ruvolo 

This year’s event also featured a Cybersecurity Challenge open to all Science Bowl students who did not compete in the final elimination rounds. Students worked individually to solve a cybersecurity-related puzzle and learn about Brookhaven’s cybersecurity efforts. Jacob Leshnower from Half Hollow Hills East took first place, Anant Srinivasan of Commack High School took second place, and Ishnaan Singh of Commack High School took third place.  

More about the Science Bowl  

In the 2021 Long Island Regional Science Bowl organized by Brookhaven Lab, all participating students received a Science Bowl t-shirt. Winning teams also received trophies and medals, and the top four high school teams received cash awards. Prizes were courtesy of Teachers Federal Credit Union and Brookhaven Science Associates (BSA), the event’s sponsors. BSA is the company that manages and operates Brookhaven Lab for DOE. 

The Long Island Regional Science Bowl is one of many educational opportunities organized by Brookhaven’s OEP. Every year, OEP holds science workshops, contests, internships, field trips, and more for students in kindergarten through graduate school. For more information on ways to participate in science education programs at Brookhaven Lab, visit the OEP website. 

More than 315,000 students have participated in NSB since it was established in 1991, and it is one of the nation’s largest science competitions. The U.S. Department of Energy’s Office of Science manages the NSB Finals competition. More information is available on the NSB website. 

Brookhaven National Laboratory is supported by the U.S. Department of Energy’s 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 https://energy.gov/science.

Follow @BrookhavenLab on Twitter or find us on Facebook.

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Valentina Bisogni. Photo from BNL

By Daniel Dunaief

Nature plays a wonderful game of hide-and-seek with its secrets.

One day, Joan might be searching for, say, an apple tree in the forest. Joan might consider all the elements that appeal to an apple tree. She might expect the journey to take two hours but, to her surprise, discovers a tree on the way.

That’s what happened to Valentina Bisogni, a physicist at Brookhaven National Laboratory. Bisogni, who works at the National Synchrotron Lightsource II, wanted to figure out how the thickness in a magnetic film affected traveling modes involving the spin property of electrons, known as spin waves. Specifically, she wanted to control the energy of the spin wave.

This might be important in future devices that involve passing along information through an electron’s spin rather than through charge, which is the current method. Controlling the spin wave could be another way to optimize the performance or improve the efficiency of future devices.

Transmitting charge creates unwanted heat, which can damage the components of an electronic device and limit its usefulness. Heat also creates energy inefficiencies.

Valentina Bisogni with a collection of tomatoes in a garden in Bellport Village. Photo by Claudio Mazoli.

Bisogni, who arrived at BNL in 2014, has been working on a beamline called Soft Inelastic X-ray Scattering, or SIX. Each of the new beamlines at the nearly billion-dollar facility has its own acronym and number that corresponds to their location in the accelerator ring.

Before she planned to apply an electric field that might control the spin wave, however, Bisogni figured she’d explore the way thinner iron materials affected the spin.

That’s when the metaphorical apple tree appeared, as the thickness of iron films, that were as thin as one to 10 nanometers, helped control the spin wave before applying any electric field.

“This result was not expected,” Bisogni said. This was preparatory work to a more detailed, dedicated study. 

“Not having had any benchmark of iron crystals in general with the technique I am using, it was logical to study this system from a bulk/ thin form to a very thin film,” she explained in an email.

Bisogni and a team from Yale University recently published the results of this work in the journal Nature Materials.

While this unexpected result is encouraging and could eventually contribute to the manufacture of electronic devices, Bisogni said this type of discovery helps build a fundamental understanding of the materials and their properties at this size.

“For people assembling or designing devices or wave guides, I think this is an ingredient that has to be considered in the future,” Bisogni said.

This kind of result could enable the optimization of device performance. When manufacturers propagate a signal based on spin dynamics, they would likely want to keep the same frequency, matching the signal along a medium from point A to point B.

The effect of the thickness on the spin was like a power log, which is not quite exponential as the experimenters tested thinner material, she said.

Bisogni plans to continue with this collaboration, as the group is “excellent in preparing and characterizing this kind of system.”

In the bigger picture, Bisogni is focused on quantum materials and altering their spin.

She is also overseeing the development of a system called Opera, which copies the working conditions of electronic devices. Opera is the new sample environment available at SIX and is developed within the research project to copy device-working conditions in the beamline’s measurement chamber.

Bisogni ultimately hopes her work may improve the energy efficiency of electronics.

A resident of Bellport Village, Bisogni lives with her partner Claudio Mazoli, who is the lead scientist for another beamline at the NSLS II, called the Coherent Soft X-ray Scattering, or CSX.

Bisogni said the couple frequently enjoy exchanging ideas and have an ongoing active collaboration, as they share several scientific passions.

The couple met at the European Synchrotron Radiation Facility in Grenoble, France when they were working in the same lab.

Bisogni was born and raised in Spoleto, which is in the province of Perugia in the center of Italy. Bisogni speaks Italian and English as well as French and German after her work experience in France, Germany and Switzerland.

Bisogni said she and Mazoli are “very food-centric” and can find numerous epicurean opportunities in the area of Long Island and New York City. The weather is also similar to home, although they miss their family and friends from Italy.

The couple purchased a house together during the pandemic and have been doing some work to shape the house to their needs. They remodeled the bathrooms in an Italian/ European style, purchased a German washing machine and dryer and painted some walls.

In the summer, Bisogni, who likes to eat, cook and grow vegetables, enjoys spinach, tomatoes and light-green zucchini.

As for her work, Bisogni is currently pleased with the state of her beamline, although she said its development took considerable team effort and time during the development, construction and commissioning.

At this point, her research team includes two and a half permanent scientists and two post-doctoral scientists. Within the team, they have two post-doc researcher positions looking to fill, one for her research project and another dedicated to her colleague’s research project.

Ultimately, Bisogni is excited with the opportunities to make fundamental discoveries at work.

“It is, in general, very exciting, as most likely you are doing something for the first time,” Bisogni explained in an email. “It is true that you may fail, since nobody is going to tell you if what you are doing is going to work or not, but if you get it right, then it is extremely rewarding.”

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Qiang Li. Photo courtesy of BNL

By Daniel Dunaief

Decades ago, most people could only tune to shows like The Jetsons to imagine interactive televisions in which people could see each other during conversations.

Qiang Li. Photo courtesy of BNL

In modern times, hand held devices and laptop computers have turned those science fiction ideas into everyday realities, as people can tell their phones to call their mom, to provide the outdoor temperature or to help them recall the name of a movie they saw decades ago.

These helpful technological devices, however, may some day go the way of the clunky desktop computers of yesteryear, as scientists around the world work to turn the vision of a quantum computer into a reality.

Scientists hope to develop a next generation of quantum computer that is faster, smarter, more flexible and more energy-efficient than current technological devices. They hope these devices could be the key to future technological breakthroughs, inspiring them to figure out how to bring the theory to life.

Collaborating with scientists at Ames Laboratory in Iowa, Qiang Li, SUNY Empire Innovation Professor in the Department of Physics and Astronomy at Stony Brook University and Leader of the Advanced Energy Materials Group at Brookhaven National Laboratory, recently published a study in the journal Nature Materials that provided fundamental information that might contribute to the field of quantum computers.

The group of scientists, which included Li’s PhD student Pedro Lozano, discovered a light-induced switch that twists the crystal lattice of a semimetal, turning on an electron current that the team believes is nearly dissipationless.

When currents move through wires between utilities and people’s homes and offices, that current encounters resistance, losing energy along the way, as if the movement towards the home created a tax on the journey. Similarly, dissipation inside an electronic device can sap some of the energy needed to transmit information or a signal, reducing the effectiveness of the process.

Li and BNL physicist Genda Gu synthesized, patterned and characterized the material at BNL, while Jigang Wang, a senior scientist at Ames Laboratory, performed the light-induced lattice twisting. The team helped create the light-induced switch.

Li described the effort as “fundamental research” and cautioned that any such advancement is more of a principal study, rather than a step closer to making any new qubit (the basic unit of quantum information) device.

“This is an experimental study to show that this is possible,” Li said. “It’s a demonstration of feasibility that you can harness chirality for building quantum information systems.”

With chirality, electrons have a handedness based on whether their spin and momentum are aligning in the same or opposite direction.

Once electrons have chirality, they can travel much easier, enabling a more direct and predictable route from one place to another.

Scientists like Li would like to create physical systems that enable them to control the chirality, preventing the spin from switching from one direction to the other.

Numerous factors can disrupt the chirality of an electron, including imperfections in the material.

A pulse-triggered light-induced switch can change the topology of a Weyl semimetal, making it possible to enable the movement of electrons that are nearly dissipationless. “For pure electronics, even computer chips, electrons consume a lot of energy because of electrical resistance,” Li said. “A chiral current [however] will travel without resistance, in ideal cases without chirality flipping.”

Chiral electrons travel through the semimetal at a speed as high as 1/300th of the speed of light and can travel considerably further before a collision that alters its direction, speed, or other particle properties. The mean free path, which is the average distance a particle will travel between such disruptive events, for a typical metal is nanometers. By contrast the chiral electrons can move micrometers, which is thousands of times longer.

An unperturbed chiral electron could travel further distances over shorter intervals, carrying preserved coded information without losing much energy during movement. 

Scientists have sought ways to create a path through which electrons travel with this predictable spin. They can break chiral symmetry by applying a magnetic field, which led to the discovery of the chiral magnetic effect by a team of scientists from BNL and Stony Brook University, including Dmitri Kharzeev, in 2014.  

For this work, Li received the Brookhaven Science and Technology Award in 2019.

“Using a magnetic field is problematic for some computations,” he said. Besides, people don’t want a “big magnet around your computers.”

Another way is to send in the laser pulse, creating left-handed or right-handed polarization.

To determine the ideal pulse to change the material, Li and Wang partnered with several theorists from Ames Lab and Ilias Perakis, Professor and Chair of Physics at the University of Alabama — Birmingham.

The theorists conducted detailed analysis of the lattice vibrations and the ideal pulse energy needed to break symmetry in the Weyl semimetal. “There is a very strong collaboration between the theorists and the experimentalists,” Li said.

While the research remains fundamental and is unlikely to generate a specific product any time soon, Li said it has “attracted a lot of attention” from other scientists and is a significant step forward in establishing the basic principles for topology-enabled quantum logic and information systems.

Li and Wang have been collaborating on this project for about two years as scientists around the world are in a “horse race” to produce results in the arena of quantum computing.

A resident of Setauket, Li and his wife Meiling Shih, have two children. Shih, who worked in the Stony Brook Pharmacological Science Department and later at Morgan Stanley, is retired and is now a volunteer instructor of a Tai Chi class for local seniors, 

Li enjoys jogging and runs a few miles every other day.

Down the road, Li hopes to address how to make the two quantum bits talk to each other.

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Results from a study of clouds and aerosols conducted in the Azores revealed that new particles can seed the formation of clouds in the marine boundary layer—the atmosphere up to about a kilometer above Earth's surface—even over the open ocean, where the concentration of precursor gases was expected to be low. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

Understanding previously undocumented source of new particle formation will improve models of aerosols, clouds, and their impact on Earth’s climate

New results from an atmospheric study over the Eastern North Atlantic reveal that tiny aerosol particles that seed the formation of clouds can form out of next to nothingness over the open ocean. This “new particle formation” occurs when sunlight reacts with molecules of trace gases in the marine boundary layer, the atmosphere within about the first kilometer above Earth’s surface. The findings, published in the journal Nature Communications, will improve how aerosols and clouds are represented in models that describe Earth’s climate so scientists can understand how the particles—and the processes that control them—might have affected the planet’s past and present, and make better predictions about the future.

“When we say ‘new particle formation,’ we’re talking about individual gas molecules, sometimes just a few atoms in size, reacting with sunlight,” said study co-author Chongai Kuang, a member of the Environmental and Climate Sciences Department at the U.S. Department of Energy’s Brookhaven National Laboratory. “It’s interesting to think about how something of that scale can have such an impact on our climate—on how much energy gets reflected or trapped in our atmosphere,” he said.

Using an aircraft outfitted with 55 atmospheric instrument systems, scientists traversed horizontal tracks above and through clouds and spiraled down through atmospheric layers to provide detailed measurements of aerosols and cloud properties. The aircraft data were supplemented by measurements made by ground-based radars and other instruments. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

But modeling the details of how aerosol particles form and grow, and how water molecules condense on them to become cloud droplets and clouds, while taking into consideration how different aerosol properties (e.g., their size, number, and spatial distribution) affect those processes is extremely complex—especially if you don’t know where all the aerosols are coming from. So a team of scientists from Brookhaven and collaborators in atmospheric research around the world set out to collect data in a relatively pristine ocean environment. In that setting, they expected the concentration of trace gases to be low and the formation of clouds to be particularly sensitive to aerosol properties—an ideal “laboratory” for disentangling the complex interactions.

“This was an experiment that really leveraged broad and collaborative expertise at Brookhaven in aerosol observations and cloud observations,” Kuang said. Three of the lead researchers—lead authors Guangjie Zheng and Yang Wang, and Jian Wang, principal investigator of the Aerosol and Cloud Experiments in the Eastern North Atlantic [https://www.arm.gov/publications/backgrounders/docs/doe-sc-arm-16-020.pdf] (ACE-ENA) campaign—began their involvement with the project while working at Brookhaven and have remained close collaborators with the Lab since moving to Washington University in St. Louis in 2018.

Land and sea

Brookhaven Lab atmospheric scientist Chongai Kuang (center) with Art Sedlacek (left) and Stephen Springston (right) aboard ARM’s Gulfstream-159 (G-1) aircraft during a 2010 atmospheric sampling mission that was not part of this study. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

The study made use of a long-term ground-based sampling station on Graciosa Island in the Azores (an archipelago 850 miles west of continental Portugal) and a Gulfstream-1 aircraft outfitted with 55 atmospheric instrument systems to take measurements at different altitudes over the island and out at sea. Both the ground station and aircraft belong to the DOE Office of Science’s Atmospheric Radiation Measurement (ARM) user facility [https://www.arm.gov/], managed and operated by a consortium of nine DOE national laboratories.

The team flew the aircraft on “porpoise flights,” ascending and descending through the boundary layer to get vertical profiles of the particles and precursor gas molecules present at different altitudes. And they coordinated these flights with measurements taken from the ground station.

The scientists hadn’t expected new particle formation to be happening in the boundary layer in this environment because they expected the concentration of the critical precursor trace gases would be too low.

“But there were particles that we measured at the surface that were larger than newly formed particles, and we just didn’t know where they came from,” Kuang said.

The aircraft measurements gave them their answer.

Many of the choreographed flight paths for this study traversed the open ocean and also crossed within the ranges of the ground-based scanning radars at DOE’s Atmospheric Radiation Measurement (ARM) Climate Research Facility on Graciosa Island in the Azores. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

“This aircraft had very specific flight patterns during the measurement campaign,” Kuang said. “They saw evidence that new particle formation was happening aloft—not at the surface but in the upper boundary layer.” The evidence included a combination of elevated concentrations of small particles, low concentrations of pre-existing aerosol surface area, and clear signs that reactive trace gases such as dimethyl sulfide were being transported vertically—along with atmospheric conditions favorable for those gases to react with sunlight.

“Then, once these aerosol particles form, they attract additional gas molecules, which condense and cause the particles to grow to around 80-90 nanometers in diameter. These larger particles then get transported downward—and that’s what we’re measuring at the surface,” Kuang said.

“The surface measurements plus the aircraft measurements give us a really good spatial sense of the aerosol processes that are happening,” he noted.

At a certain size, the particles grow large enough to attract water vapor, which condenses to form cloud droplets, and eventually clouds.

Both the individual aerosol particles suspended in the atmosphere and the clouds they ultimately form can reflect and/or absorb sunlight and affect Earth’s temperature, Kuang explained.

Study implications

Framed by a brilliant rainbow, ARM’s Gulfstream-159 (G-1) research aircraft sits on the tarmac on Terceira Island during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) winter 2018 intensive operation period in the Azores. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

So now that the scientists know new aerosol particles are forming over the open ocean, what can they do with that information?

“We’ll take this knowledge of what is happening and make sure this process is captured in simulations of Earth’s climate system,” Kuang said.

Another important question: “If this is such a clean environment, then where are all these precursor gases coming from?” Kuang asked. “There are some important precursor gases generated by biological activity in the ocean (e.g., dimethyl sulfide) that may also lead to new particle formation. That can be a nice follow-on study to this one—exploring those sources.”

Understanding the fate of biogenic gases such as dimethyl sulfide, which is a very important source of sulfur in the atmosphere, is key to improving scientists’ ability to predict how changes in ocean productivity will affect aerosol formation and, by extension, climate.

The research was funded by the DOE Office of Science, DOE’s Atmospheric System Research, and by NASA. In addition to the researchers from Brookhaven Lab and Washington University, the collaboration included scientists from Pacific Northwest National Laboratory; Missouri University of Science and Technology; the University of Washington, Seattle; NASA Langley Research Center; Science Systems and Applications Inc. in Hampton, Virginia; the Max Planck Institute for Chemistry in Mainz, Germany; and the Scripps Institution of Oceanography, University of California, San Diego.

Brookhaven National Laboratory 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 science.energy.gov [https://www.energy.gov/science/office-science].

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Accelerator physicist Chuyu Liu, the run coordinator for this year's experiments at the Relativistic Heavy Ion Collider (RHIC), in the Main Control Room of the collider-accelerator complex at Brookhaven National Laboratory.

Final stage of Beam Energy Scan II will collect low-energy collision data needed to understand the transition of ordinary nuclear matter into a soup of free quarks and gluons

Accelerator physicists are preparing the Relativistic Heavy Ion Collider (RHIC), a DOE Office of Science user facility for nuclear physics research at DOE’s Brookhaven National Laboratory, for its 21st year of experiments, set to begin on or about February 3. Instead of producing high-energy particle smashups, the goal for this run is to maximize collision rates at the lowest energy ever achieved at RHIC.

STAR co-spokesperson Lijuan Ruan noted that this year’s run is the third and final leg of Beam Energy Scan II, a systematic study of RHIC collisions at low energies.

“Run 21 is the final step of Beam Energy Scan II (BES-II), a three-year systematic study of what happens when gold ions—gold atoms stripped of their electrons—collide at various low energies,” said Brookhaven physicist Lijuan Ruan, co-spokesperson for RHIC’s STAR experiment collaboration.

Nuclear physicists will examine the BES-II data, along with data from RHIC’s high-energy collisions, to map out how these collisions transform ordinary protons and neutrons into an extraordinary soup of free quarks and gluons—a substance that mimics what the early universe was like some 14 billion years ago. By turning the collision energy down, RHIC physicists can change the temperature and other variables to study how these conditions affect the transition from ordinary matter to early-universe hot quark-and-gluon soup.

“Out of the five energies of BES-II—9.8, 7.3, 5.75, 4.6, and 3.85 billion electron volts, or GeV—this year’s run at 3.85 GeV is the most difficult one,” said Brookhaven Lab accelerator physicist Chuyu Liu, the run coordinator. That’s because “RHIC’s beams of gold ions are really difficult to hold together at the lowest energy,” he explained.

In Run 21, the accelerator team will use a variety of innovative components and schemes to maintain the lifetime and intensity of the colliding ion beams under challenging conditions. Read on to learn more about RHIC’s Run 21 science goals and the accelerator features that will make the science possible.

Scanning the transition

Mapping nuclear phase changes is like studying how water changes under different conditions of temperature and pressure (net baryon density for nuclear matter). RHIC’s collisions “melt” protons and neutrons to create quark-gluon plasma (QGP). STAR physicists are exploring collisions at different energies, turning the “knobs” of temperature and baryon density, to look for signs of a “critical point.” That’s a set of conditions where the type of transition between ordinary nuclear matter and QGP changes from a smooth crossover observed at RHIC’s highest energies (gradual melting) to an abrupt “first order” phase change that’s more like water boiling in a pot.

As Ruan explained, the quest to map out the phases of nuclear matter and the transitions between them is somewhat similar to studying how water molecules transform from solid ice to liquid water and gaseous steam at different temperatures and pressures. But nuclear matter is trickier to study.

“We need a powerful particle collider and sophisticated detector systems to create and study the most extreme forms of nuclear matter,” she said. “Thanks to the incredible versatility of RHIC, we can use the ‘knob’ of collision energy and the intricate particle-tracking capabilities of the STAR detector to conduct this systematic study.”

RHIC’s highest collision energies (up to 200 GeV) produce temperatures more than 250,000 times hotter than the center of the Sun. Those collisions “melt” the protons and neutrons that make up gold atoms’ nuclei, creating an exotic phase of nuclear matter called a quark-gluon plasma (QGP). In QGP, quarks and gluons are “free” from their ordinary confinement within protons and neutrons, and they flow with virtually no resistance—like a nearly perfect liquid.

But QGP lasts a mere fraction of a second before “freezing out” to form new particles. RHIC physicists piece together details of how the melting and refreezing happen by taking “snapshots” of the particles that stream out of these collisions.

By systematically lowering the collision energy, the physicists are looking for signs of a so-called “critical point.” This would be a set of conditions where the type of transition between ordinary nuclear matter and QGP changes from the smooth crossover observed at RHIC’s highest energies (picture butter melting gradually on a counter), to an abrupt “first order” phase change (think of how water boils suddenly at a certain temperature and holds that temperature until all the molecules evaporate).

As physicists turn RHIC’s collision energy down, they expect to see large event-by-event fluctuations in certain measurements—similar to the turbulence an airplane experiences when entering a bank of clouds—as conditions approach a “critical point” in the nuclear phase transition. This year’s run at the lowest collision energy will contribute to this search.

“Theorists have predicted that certain key measurements at RHIC will exhibit dramatic event-by-event fluctuations when we approach this critical point,” Ruan said.

Some RHIC physicists liken these fluctuations to the turbulence an airplane experiences when it moves from smooth air into a bank of clouds and then back out again. Measurements from phase I of RHIC’s Beam Energy Scan (BES-I, with data collected between 2010 and 2017) revealed tantalizing hints of such turbulence. But because collisions are hard to achieve at low energies, the data from BES-I aren’t strong enough to draw definitive conclusions.

Now, in BES-II, a host of accelerator improvements have been implemented to maximize low-energy collision rates.

Cooling the ions

One of the innovations that Chuyu Liu and the other Collider-Accelerator Department (C-AD) physicists managing RHIC operations will take advantage of in Run 21 is a first-of-its-kind beam-cooling system. This Low Energy RHIC electron Cooling  (LEReC) system operated at full capacity for the first time in last year’s RHIC run, making it the world’s first implementation of electron cooling in a collider. But it will be even more important for the lowest-of-low collision energies this year.

“The longer the beam stays at low energy, the more ‘intra-beam scattering’ and ‘space charge’ effects degrade the beam quality, reducing the number of circulating ions,” said Liu. Simplistic translation: The positively charged ions tend to repel one another. (Remember: The ions are atoms of gold stripped of their electrons, leaving a lot of net positive charge from the 79 protons in the nucleus.) The scattering and the repulsive space charge cause the ions to spread out, essentially heating up the beam as it makes its way around the 2.4-mile-circumference RHIC accelerator. And spread-out ions are less likely to collide.

A host of accelerator improvements have been implemented to maximize RHIC’s low-energy collision rates. These include a series of components that inject a stream of cool electron bunches into the ion beams in these cooling sections of the two RHIC rings. The cool electrons extract heat to counteract the tendency of RHIC’s ions to spread out, thereby maximizing the chances the ions will collide when the beams cross at the center of RHIC’s STAR detector.

“The LEReC system operates somewhat similar to the way the liquid running through your home refrigerator extracts heat to keep your food cool,” said Wolfram Fischer, Associate Chair for Accelerators in C-AD, “but the technology needed to achieve this beam cooling is quite a bit more complicated.”

A series of components (special lasers and a photocathode gun) produces bunches of relatively cool electrons, which are accelerated to match the bunching and near-light-speed pace of RHIC’s ions. Transfer lines inject the cool electrons into the stream of ion bunches—first in one RHIC ring, then, after making a 180-degree turn, into the other. As the particles mix, the electrons extract heat, effectively squeezing the spread-out ion bunches back together. The warmed-up electron bunches then get dumped and replaced with a new cool batch.

“To add more flexibility for cooling optimization during this year’s run at RHIC’s lowest energy, where the space-charge effects and beam lifetime degradation are concerns for both the electrons and the ions, we installed a new ‘second harmonic’ radiofrequency (RF) cavity in the electron accelerator,” said Alexei Fedotov, the accelerator physicist who led the LEReC project.

These cavities generate the radio waves that push the electrons along their path, with the higher (second harmonic) frequency helping to flatten out the longitudinal profile of the electron bunches. “This should help to reduce the space charge effect in the electron beams to achieve better cooling performance at low energy,” Fedotov said.

“We plan to commission the new electron beam transport line in late January and start cooling ions with the new electron beam setup in early February,” he added.

More accelerator advances

Similarly, third-harmonic RF cavities installed in the ion accelerator rings will help to flatten the longitudinal profile of the ion bunches, reducing their peak intensity and space charges, Liu explained. “With that, more bunch intensity can be injected into RHIC to produce higher luminosity—a measure closely tied to collision rates,” he said.

The accelerator team will also be commissioning a new bunch-by-bunch feedback system to help stabilize the beam for a better lifetime. “This system measures how each ion bunch deviates from the center of the beam pipe, and then applies a proportional correction signal through a component called a kicker to nudge each bunch back to where it should be,” Liu said.

All this cooling and nudging will counteract the ions’ tendency to spread, which maximizes chances of collisions happening when the two beams cross at the center of STAR.

“This run will bring together many of the advances we’ve been working on at RHIC to meet the challenging conditions of low-energy collisions,” said Fischer. “STAR would have preferred to test the lowest energy first, but we needed to learn everything possible (and develop the electron cooling system) before we could embark on operation at the most difficult energy.”

RHIC operations are funded by the DOE Office of Science.

Brookhaven National Laboratory is supported by the U.S. Department of Energy’s 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 https://www.energy.gov/science/ [https://www.energy.gov/science/].

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