Nigel Lockyer appointed to second term as director of Fermilab

Nigel Lockyer has been reappointed as the director of the U.S. Department of Energy’s Fermi National Accelerator Laboratory. During his first four years as leader of the world-renowned laboratory he helped enhance its international scientific leadership, including the launch of a pioneering international particle physics project hosted by Fermilab.

Lockyer’s second five-year term, which begins Sept. 3, 2018, comes as Fermilab begins building its flagship project that will send neutrino particles underground from Illinois to South Dakota to unlock new insights into the origins of the universe. The lab is also a leader in the Large Hadron Collider at CERN in Switzerland while serving as the home of groundbreaking experiments conducted by scientists from around the world.

“For decades, scientists working at Fermilab have made major discoveries that have greatly illuminated the nature of matter and the universe. Under Nigel’s outstanding leadership, Fermilab is not only continuing many of its important ongoing projects, but has embarked upon a new ambitious research agenda for the coming years that will enable further profound discoveries,” said Robert J. Zimmer, president of the University of Chicago and chair of the Board of Directors of Fermi Research Alliance LLC.

The Fermi Research Alliance, which was formed in 2006, is a joint partnership of the University of Chicago and the Universities Research Association Inc. Together they manage Fermilab under a contract with the Department of Energy. Fermilab’s operations include a powerful complex of particle accelerators and sophisticated experiments to study the nature of matter, energy, space and time, with more than 4,500 scientists from 50 countries using the research facilities annually.

“On behalf of the Universities Research Association, Nigel has been an extraordinary leader, and we join the University of Chicago in enthusiastically supporting this reappointment,” said Lou Anna K. Simon, chair of the Universities Research Association and vice chair of Fermi Research Alliance LLC.

During his first term, Lockyer positioned Fermilab as a world leader in research of neutrinos, spearheading the successful launch of the Long-Baseline Neutrino Facility with locations in Illinois and South Dakota. The facility will house the Deep Underground Neutrino Experiment, a massive research project that brings together more than 1,000 scientists from 31 countries in a quest to understand the hard-to-detect particles and usher in a new era of international particle physics research.

“DOE is committed to supporting world-leading science at its national laboratories,” said Steve Binkley, acting director of the DOE Office of Science. “LBNF/DUNE exemplifies America’s strong partnerships with the international community in pioneering scientific discoveries.”

Lockyer has forged new international partnerships dedicated to advancing experiments at the laboratory while retaining Fermilab’s leadership in the Large Hadron Collider and Compact Muon Solenoid experiment at CERN. Fermilab has contributed major components for the collider’s accelerator and Compact Muon Solenoid experiment upgrades.

As Fermilab director, Lockyer has continued Fermilab’s trailblazing program in particle astrophysics that seeks to understand the nature of dark energy and discover particles of dark matter. He has led efforts to revitalize the laboratory’s infrastructure, accelerated the laboratory’s efforts to translate scientific discoveries to applications for society and kicked off new initiatives such as Fermilab’s participation in the Chicago Quantum Exchange.

Lockyer earned a bachelor’s degree in physics from York University and a doctorate in physics from the Ohio State University. He served for more than two decades as a physics faculty member at the University of Pennsylvania.

Before arriving at Fermilab, Lockyer was director of Canada’s TRIUMF laboratory for particle and nuclear physics and a professor of physics and astronomy at the University of British Columbia. He is the 2006 recipient of the American Physical Society’s Panofsky Prize for his leading research on the bottom quark.

Fermilab is America’s particle physics and accelerator laboratory. 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 us on Twitter at @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.

Fermi Research Alliance LLC operates Fermilab under contract with the U.S. Department of Energy’s Office of Science. FRA is a partnership of the University of Chicago and Universities Research Association Inc., a consortium of 90 research universities.

What does it take to throw the biggest Fermilab Open House in decades?

Months of planning, 80 buses, 900 eager workers, four Mr. Freeze shows, 15,000 brochures, 28 bison, two muon experiments, 25 neutrino trading cards, 50 years of incredible science—and 10,000 friends of Fermilab.

Sept. 23 felt more like summer than the second day of fall, but Fermilab fans, new friends and future scientists were undeterred by the heat and enjoyed a full day of scientific discovery. The Fermilab Community Open House commemorating the laboratory’s 50^th anniversary provided visitors the unique opportunity to see parts of the lab rarely open to the public, like the 350-foot-deep shaft leading to Fermilab’s neutrino experiment cavern or the lab’s state-of-the art factory for particle detectors.

For most visitors, there was too much to see and do in one day, but every part of the Fermilab campus seemed full of enthusiastic faces, soaking up science, and equally exuberant lab staff and collaborators sharing what they do at Fermilab.

“It’s high-level physics geeks talking about high-level physics — what’s not to love?” said one upbeat visitor.

Among the more popular attractions were the Muon g-2 experiment, with its famous magnet, which arrived at Fermilab in 2013 from Long Island, New York; Mr. Freeze and his cool cryogenic shows, wowing crowds with liquid nitrogen; and the Chicagoland STEM Fair, where visitors had the chance to engage with science through demonstrations from Chicagoland’s STEM community.

The Lederman Science Education Center was also a hot spot for hands-on family fun, with easy-to-understand demonstrations of the science that drives Fermilab experiments.

“I enjoyed the tour of Fermilab’s linear accelerator, but at first my kids didn’t quite understand the science,” said Feng, a Naperville resident. “As soon as we came to the accelerator table at the science center, it clicked and now they understand how it works too.”

Many visitors checked out parts of the laboratory’s linear accelerator, as well as the Main Control Room, where lab employee monitor the passage of particle beams through the accelerator complex.

“Your 50th Anniversary was very educational and totally cool,” said another guest. “The buildings, experiments all very educational. I must say that Fermilab itself is a United Nations of great people who as we saw were happy, friendly, full of smiles and very grateful to show us the behind the scenes of their workplaces.”

Other attractions included the Technical Campus, which offered a chance to visit the bison and those who care for them, learn about how Fermilab makes superconducting magnets, and to chat live with scientists from CERN in Switzerland. From there, visitors could take buses to see facilities such as the Cryomodule Test Facility where new, state-of-the-art particle accelerator technologies are developed. They could also visit the Silicon Detector Facility, where visitors could learn all about Fermilab’s study of dark matter and dark energy; the development of next-generation particle detector components and quantum sensors; and Fermilab’s contribution to the South Pole Telescope — not to mention the historic, otherworldly-looking Bubble Chamber.

“Thank you so much for your fantastic Open House. The employees were so informative, welcoming and positive even in the crazy heat,” said one visitor. “It was wonderful to be able to show our young boys such tremendous science right here in the Chicagoland area.  Our whole family enjoyed learning together! In the words of our seven-year-old, “It was amazing!'”

The muon and neutrino experiments were a big hit too with adults and kids alike.

“We got to see all the muon experiments and then we got to see ICARUS. It was super cool!” said Jack, a nine-year-old Chicago resident. ICARUS is a 760-ton neutrino detector that was delivered to Fermilab from CERN in July. “My favorite part was going down into the tunnel to see the Muon Delivery Ring,” he said.

Jack plans to be a future Fermilab scientist, but he’ll be back before then.

“We’ve already marked the Family Open House in February on our calendar!” added his mom.

Wilson Hall was a hub of science, art, history and advanced computing. Guests also got to learn about some of Fermilab’s partners, such as the Department of Energy, Sanford Lab and IBM, who hosted an exhibit on quantum computers.

Fermilab’s Open House was a big hit, and there’s no better way to celebrate 50 years of science than to share the excitement with the laboratory’s friends and neighbors. If you missed the Open House or didn’t get a chance to see everything you wanted to, the Fermilab site is open every day of the year. The lab hosts events, tours and plenty of other opportunities to learn about Fermilab’s mission to discover more about our universe. We hope you’ll be part of our next 50 years!

Read more about the Fermilab Community Open House in The Beacon-News, The Daily Herald and Naperville Community Television.

To see Fermilab’s full calendar of science, nature, education and cultural events for adults and kids, visit events.fnal.gov.

UK minister Jo Johnson traveled to the United States this week to sign the first ever umbrella science and technology agreement between the two nations and to announce approximately $88 million in funding for the international Long-Baseline Neutrino Facility and Deep Underground Neutrino Experiment.

On Thursday, he visited the host laboratory for LBNF/DUNE, the U.S. Department of Energy’s Fermi National Accelerator Laboratory, emphasizing the importance of the project and the strong scientific partnership between the two countries.

Johnson, the UK minister of state for universities, science, research and innovation, signed the agreement on Wednesday in Washington, D.C. Signing for the United States was Judith G. Garber, acting assistant secretary of state for oceans and international environmental and scientific affairs.

This new agreement lays the groundwork for additional collaboration between the U.S. DOE, its national laboratories (including Fermilab) and the UK Science and Technology Facilities Council. STFC funds research in particle physics, nuclear physics, space science and astronomy in the United Kingdom. The U.S. DOE is the largest supporter of basic research in the physical sciences in the United States.

“Our continued collaboration with the U.S. on science and innovation benefits both nations,” said Johnson, “and this agreement will enable us to share our expertise to enhance our understanding of many important topics that have the potential to be world changing.”

LBNF/DUNE will be a world-leading international neutrino experiment based in the United States. Fermilab’s powerful particle accelerators will create the world’s most intense beam of neutrinos and send it 800 miles through Earth to massive particle detectors, which will be built a mile underground at the Sanford Underground Research Facility in South Dakota.

The UK research community is already a major contributor to the DUNE collaboration, providing expertise and components to the facility and the experiment. UK contributions range from the high-power neutrino production target to the data acquisition systems to the software that reconstructs particle interactions into visible 3-D readouts.

DUNE will be the first large-scale experiment hosted in the United States that runs as a truly international project, with more than 1,000 scientists and engineers from 31 countries building and operating the facility. Its goal is to learn more about ghostly particles called neutrinos, which may provide insight into why we live in a matter-dominated universe that survived the Big Bang.

In addition to Johnson, the UK delegation to Fermilab included Brian Bowsher, chief executive of STFC; Andrew Price of the UK Science and Innovation Network; and Martin Whalley, deputy consul general from the Great Britain Consulate in Chicago.

They toured several areas of the lab, including the underground cavern that houses the NOvA neutrino detector, and the Cryomodule Test Facility, where components of the accelerator that will power DUNE are being tested. The UK will contribute world-leading expertise in particle accelerators to the upgrade of Fermilab’s neutrino beam and accelerator complex.

“This investment is part of a long history of UK research collaboration with the U.S.,” said Bowsher. “International partnerships are the key to building these world-leading experiments, and I am looking forward to seeing our scientists work with our colleagues in the U.S. in developing this experiment and the exciting science that will happen as a result.”

UK institutions have been a vital part of Fermilab’s 50-year history, from the earliest days of the laboratory. UK labs and universities were important partners in the main Tevatron experiments, CDF and DZero, in the 1980s and 1990s. UK institutions have been involved with accelerator research and development, are partners in Fermilab’s muon experiments and are at the forefront of Fermilab’s focus on neutrino physics.

Sixteen UK institutions (14 universities and two STFC-funded labs) are contributors to the DUNE collaboration, the U.S.-hosted centerpiece for a world-class neutrino experiment. The collaboration is led by Mark Thomson, professor of experimental particle physics at the University of Cambridge, and Ed Blucher, professor and chair of the Department of Physics at the University of Chicago.

“Our colleagues in the United Kingdom have been critical partners for Fermilab, for LBNF/DUNE and for the advancement of particle physics around the world,” said Fermilab Director Nigel Lockyer. “We look forward to the discoveries that these projects will bring.”

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.

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.

Particle accelerators are the engines of particle physics research at Fermilab. They generate nearly light-speed, subatomic particles that scientists study to get to the bottom of what makes our universe tick. Fermilab experiments rely on a number of different accelerators, including a powerful, 500-foot-long linear accelerator that kick-starts the process of sending particle beams to various destinations.

But if you’re not doing physics research, what’s an accelerator good for?

It turns out, quite a lot: Electron beams generated by linear accelerators have all kinds of practical uses, such as making the wires used in cars melt-resistant or purifying water.

A project called Accelerator Application Development and Demonstration (A2D2) at Fermilab’s Illinois Accelerator Research Center will assist Fermilab and its partners to explore new applications for compact linear accelerators, which are only a few feet long rather than a few hundred. These compact accelerators are of special interest because of their small size — they’re cheaper and more practical to build in an industrial setting than particle physics research accelerators — and they can be more powerful than ever.

“A2D2 has two aspects: One is to investigate new applications of how electron beams might be used to change, modify or process different materials,” said Fermilab’s Tom Kroc, an A2D2 physicist. “The second is to contribute a little more to the understanding of how these processes happen.”

To develop these aspects of accelerator applications, A2D2 will employ a compact linear accelerator that was once used in a hospital to treat tumors with electron beams. With a few upgrades to increase its power, the A2D2 accelerator will be ready to embark on a new venture: exploring and benchmarking other possible uses of electron beams, which will help specify the design of a new, industrial-grade, high-power machine under development by IARC and its partners.

It won’t be just Fermilab scientists using the A2D2 accelerator: As part of IARC, the accelerator will be available for use (typically through a formal CRADA or SPP agreement) by anyone who has a novel idea for electron beam applications. IARC’s purpose is to partner with industry to explore ways to translate basic research and tools, including accelerator research, into commercial applications.

“I already have a lot of people from industry asking me, ‘When can I use A2D2?’” said Charlie Cooper, general manager of IARC. “A2D2 will allow us to directly contribute to industrial applications — it’s something concrete that IARC now offers.”

Speaking of concrete, one of the first applications in mind for compact linear accelerators is creating durable pavement for roads that won’t crack in the cold or spread out in the heat. This could be achieved by replacing traditional asphalt with a material that could be strengthened using an accelerator. The extra strength would come from crosslinking, a process that creates bonds between layers of material, almost like applying glue between sheets of paper. A single sheet of paper tears easily, but when two or more layers are linked by glue, the paper becomes stronger.

“Using accelerators, you could have pavement that lasts longer, is tougher and has a bigger temperature range,” said Bob Kephart, director of IARC. Kephart holds two patents for technologies related to cross-linking pavement materials. “Basically, you’d put the road down like you do right now, and you’d pass an accelerator over it, and suddenly you’d turn it into really tough stuff — like the bed liner in the back of your pickup truck.”

This process has already caught the eye of the U.S. Army Corps of Engineers, which will be one of A2D2’s first partners. Another partner will be the Chicago Metropolitan Water Reclamation District, which will test the utility of compact accelerators for water purification. Many other potential customers are lining up to use the A2D2 technology platform.

“You can basically drive chemical reactions with electron beams — and in many cases those can be more efficient than conventional technology, so there are a variety of applications,” Kephart said. “Usually what you have to do is make a batch of something and heat it up in order for a reaction to occur. An electron beam can make a reaction happen by breaking a bond with a single electron.”

In other words, instead of having to cook a material for a long time to reach a specific heat that would induce a chemical reaction, you could zap it with an electron beam to get the same effect in a fraction of the time.

In addition to exploring the new electron-beam applications with the A2D2 accelerator, scientists and engineers at IARC are using cutting-edge accelerator technology to design and build a new kind of portable, compact accelerator, one that will take applications uncovered with A2D2 out of the lab and into the field. The A2D2 accelerator is already small compared to most accelerators, but the latest R&D allows IARC experts to shrink the size while increasing the power of their proposed accelerator even further.

“The new, compact accelerator that we’re developing will be high power and high energy for industry,” Cooper said. “This will enable some things that weren’t possible in the past. For something such as environmental cleanup, you could take the accelerator directly to the site.”

While the IARC team develops this portable accelerator, which should be able to fit on a standard trailer, the A2D2 accelerator will continue to be a place to experiment with how to use electron beams — and study what happens when you do.

“The point of this facility is more development than research, however there will be some research on irradiated samples,” said Fermilab’s Mike Geelhoed, one of the A2D2 project leads. “We’re all excited — at least I am. We and our partners have been anticipating this machine for some time now. We all want to see how well it can perform.”

Editor’s note: Today in Washington, D.C., UK Minister of State for Universities, Science, Research and Innovation Jo Johnson signed the first ever Science and Technology Agreement between the United Kingdom and the United States and announced a commitment of approximately $88 million for the international LBNF/DUNE project. We are pleased to distribute this press release on behalf of the British Embassy in Washington, D.C., and the U.S. State Department.

The U.S. Department of Energy’s Fermi National Accelerator Laboratory is the host laboratory for the LBNF/DUNE project, which will use Fermilab’s world-leading accelerator complex to send a beam of ghostly particles called neutrinos 800 miles through Earth to a massive detector that will be built a mile below the surface at the Sanford Underground Research Facility in South Dakota.

More than a thousand scientists from institutions in more than 30 countries around the world contribute to the LBNF/DUNE project. The UK has been an essential partner in the experiment since its inception, and the collaboration includes scientists from 16 UK institutions. The U.S. contribution to LBNF/DUNE is supported by the U.S. Department of Energy.  

“The United Kingdom has long been a leader in this area of science, starting with Ernest Rutherford in the early 20th century,” said Fermilab Director Nigel Lockyer. “This agreement ensures that LBNF/DUNE will have great scientific and technical strength on the team as we chart the bright future for neutrino research.”

Joint statement by the governments of the United States of America and United Kingdom of Great Britain and Northern Ireland on the U.S.-U.K. Science and Technology Agreement

U.S. Acting Assistant Secretary of State for Oceans and International Environmental and Scientific Affairs Judith G. Garber and UK Minister of State for Universities, Science, Research and Innovation Jo Johnson signed the U.S.-UK Science and Technology Agreement on Sept. 20 in Washington, D.C. The signing ceremony marks the first ever umbrella agreement between the United States and United Kingdom outlining a commitment to collaborate on world-class science and innovation.  Accompanying Jo Johnson on the visit to the United States was Chief Executive Designate at U.K. Research and Innovation Sir Mark Walport.

Expanding the frontiers of physics

The first major project of the agreement is UK investment in the Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE), for which the UK government has confirmed approximately $88 million in funding. Construction for LBNF/DUNE is expected to create an estimated 4,000 jobs in the United States, about 2,000 in South Dakota and 2,000 in Illinois. The $88 million in funding makes the UK the largest country investor in the project outside of the United States.

The LBNF/DUNE project aims to answer some of the most important questions in science and advance our understanding of the origin and structure of the universe. One aspect of study is the behavior of neutrinos and their antimatter counterparts, antineutrinos. The project could provide insight as to why we live in a matter-dominated universe and inform the debate on why the universe survived the Big Bang.

The UK is a major scientific contributor to the DUNE collaboration, with 14 UK universities and two Science and Technology Facilities Council laboratories providing essential expertise and components to the experiment and facility. UK involvement in the project will also provide opportunities for UK industry to build capability in new and developing technologies, for example, in precision engineering, cryogenics and accelerator-based applications.

Improving digital research skills

Building on the U.S.-UK partnership, the U.S. Smithsonian Institution and the UK Arts Humanities Research Council are extending a successful history of partnerships by developing a new collaboration, based at the Smithsonian’s National Museum of American History, focused on increasing the use of digital research skills in museums. Enhancing these skills will benefit areas such as data analysis, curating, and accessibility of collections, and will also further audience engagement. This work will help achieve new best practices in digital scholarship and the application of digital technologies at research-led museums.

Breaking new ground together

The U.S.-UK scientific partnership is one of the world’s strongest, with bilateral collaborations resulting in 26 Nobel Prizes in science and economics. The investment in LBNF/DUNE is the most recent example from a long history of collaboration in industries ranging from aerospace to robotics to agriculture. U.S.-UK cooperation on science and innovation benefits both nations by sharing expertise to enhance our understanding of many important topics that have the potential to be world-changing, helping maintain our position as global leaders in research for years to come.

For further information, please contact Yoon Nam at namys@state.gov.

Read more from STFC: http://www.stfc.ac.uk/news/uk-signs-65m-science-partnership-agreement-with-us

 

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.

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.

 

Technology proposed 30 years ago to search for dark matter is finally seeing the light.

Scientists are using innovative sensors, called skipper CCDs (short for charge-coupled devices) in a new type of dark matter detection project. Scientists will use the project, known as SENSEI, to find the lightest dark matter particles anyone has ever looked for.

Dark matter — so named because it doesn’t absorb, reflect or emit light — constitutes 27 percent of the universe, but the jury is still out on what it’s made of. The primary theoretical suspect for the main component of dark matter is a particle scientists have descriptively named the weakly interactive massive particle, or WIMP.

But since none of these heavy particles, which are expected to have a mass 100 times that of a proton, have shown up in experiments, it might be time for researchers to think small.

“There is a growing interest in looking for different kinds of dark matter that are additives to the standard WIMP model,” said Fermilab scientist Javier Tiffenberg, a leader of the SENSEI collaboration. “Lightweight, or low-mass, dark matter is a very compelling possibility, and for the first time, the technology is there to explore these candidates.”

Low-mass dark matter would leave a tiny, difficult-to-see signature when it collides with material inside a detector. Catching these elusive particles requires a dark-matter-detecting master: SENSEI.

Sensing the unseen

In traditional dark matter experiments, scientists look for a transfer of energy that would occur if dark matter particles collided with an ordinary nucleus, but SENSEI is different. It looks for direct interactions of dark matter particles colliding with electrons.

“That is a big difference — you get a lot more energy transferred in this case because an electron is so light compared to a nucleus,” Tiffenberg said.

If dark matter has low mass — much smaller than the WIMP model suggests — then it would be many times lighter than an atomic nucleus. So if it were to collide with a nucleus, the resulting energy transfer would be far too small tell us anything. It would be like throwing a ping pong ball at a boulder: the heavy object isn’t going anywhere, and there would be no sign the two had come into contact.

An electron is nowhere near as heavy as an atomic nucleus. In fact, a single proton has about 1,836 times more mass than an electron. So the collision of a low-mass dark matter particle with an electron has a much better chance of leaving a mark — more bowling ball than the nucleus’s boulder.

Even so, the electron is still a bowling ball compared to the low-mass dark matter particle. An energy transfer between the two would leave only a blip of energy, one either too small for most detectors to pick up or easily overshadowed by noise in the data. There is a small exchange of energy, but, if the detector isn’t sensitive enough, it could appear as though nothing happens.

“The bowling ball will move a very tiny amount,” said Fermilab scientist Juan Estrada, a SENSEI collaborator. “You need a very precise detector to see this interaction of lightweight particles with something that is much heavier.”

That’s where SENSEI’s sensitive skipper CCDs come in: They will pick up on that tiny transfer of energy.

CCDs have been used for other dark matter detection experiments, such as the Dark Matter in CCDs (or DAMIC) experiment operating at SNOLAB in Canada. These CCDs were a spinoff from sensors developed for use in the Dark Energy Camera in Chile and other dark energy search projects.

CCDs are typically made of silicon divided into pixels. When a dark matter particle passes through the CCD, it collides with silicon’s electrons, knocking them free, leaving a net electric charge in each pixel the particle passes through. The electrons then flow through adjacent pixels and are ultimately read as a current in a device that measures the number of electrons freed from each CCD pixel. That measurement tells scientists about the mass and energy of the particle — in this case the dark matter particle — that got the chain reaction going. A massive particle, like a WIMP, would free a gusher of electrons, but a low-mass particle might free only one or two.

Typical CCDs can measure the charge left behind only once, which makes it difficult to decide if a tiny energy signal from one or two electrons is real or an error.

Skipper CCDs are a new generation of the technology that helps eliminate the “iffiness” of a measurement that has a one- or two-electron margin of error. That allows for much higher precision thanks to a unique design.

“In the past, detectors could measure the amount of charge of the energy deposited in each pixel only once,” Tiffenberg said. “The big step forward for the skipper CCD is that we are able to measure this charge as many times as we want.”

The charge left behind in the skipper CCD by dark matter knocking electrons free can be sampled multiple times and then averaged, a method that yields a more precise measurement of the charge deposited in each pixel than the measure-one-and-done technique. That’s the rule of statistics: With more data, you get closer to a property’s true value.

SENSEI scientists take advantage of the skipper CCD architecture, measuring the number of electrons in a single pixel a whopping 4,000 times and then averaging them. That minimizes the measurement’s error — or noise — and clarifies the signal.

“This is a simple idea, but it took us 30 years to get it to work,” Estrada said.

From idea, to reality, to beyond

A small SENSEI prototype is currently running at Fermilab in a detector hall 385 feet below ground, and it has demonstrated that this detector design will work in the hunt for dark matter.

After a few decades existing as only an idea, skipper CCD technology and SENSEI were brought to life by Laboratory Directed Research and Development (LDRD) funds at Fermilab and Lawrence Berkeley National Laboratory (Berkeley Lab). The Fermilab LDRDs were awarded only recently — less than two years ago — but close collaboration between the two laboratories has already yielded SENSEI’s promising design, partially thanks to Berkeley lab’s previous work in skipper CCD design.

Fermilab LDRD funds allow researchers to test the sensors and develop detectors based on the science, and the Berkeley Lab LDRD funds support the sensor design, which was originally proposed by Berkeley Lab scientist Steve Holland.

“It is the combination of the two LDRDs that really make SENSEI possible,” Estrada said.

LDRD programs are intended to provide funding for development of novel, cutting-edge ideas for scientific discovery, and SENSEI technology certainly fits the bill — even beyond its search for dark matter.

Future SENSEI research will also receive a boost thanks to a recent grant from the Heising-Simons Foundation.

“SENSEI is very cool, but what’s really impressive is that the skipper CCD will allow the SENSEI science and a lot of other applications,” Estrada said. “Astronomical studies are limited by the sensitivity of their experimental measurements, and having sensors without noise is the equivalent of making your telescope bigger — more sensitive.”

SENSEI technology may also be critical in the hunt for a fourth type of neutrino, called the sterile neutrino, which seems to be even more shy than its three notoriously elusive neutrino family members.

A larger SENSEI detector equipped with more skipper CCDs will be deployed within the year. It’s possible it might not detect anything, sending researchers back to the drawing board in the hunt for dark matter. Or SENSEI might finally make contact with dark matter — and that would be SENSEI-tional.