From JHU HUB and University of Maryland (US) : “What’s in a name? MARCC becomes ARCH turbocharging Hopkins high-performance computing”

From JHU HUB

and

University of Maryland (US)

8.2.21

Lisa Ercolano

The computing center gets a new name and expanded mission that will enhance resource sharing to drive data-intensive computational discoveries.

Rockfish computing cluster. Credit: Getty Images.

When Johns Hopkins and the University of Maryland (US) launched the Maryland Advanced Research Computing Center or MARCC, in 2015, it was hailed as one of the nation’s largest academic high-performance computing centers. Located on the Johns Hopkins Bayview Medical Center campus in East Baltimore and supported by $30 million in state funding, MARCC’s swift fiber-optic cable connection lets investigators conduct research on everything from deadly diseases to distant galaxies without having to leave their laboratories or offices. In addition, all participants shared the costs of networking and running a single entity, rather than spending time, money, and space to create their own high-performance computing centers.

“MARCC set Maryland on the map for high-performance computing,” said Jaime Combariza, a Johns Hopkins computational chemist and MARCC’s director. “In fact, its success sparked a renaissance of interest in high-performance computing at Hopkins.”

This remarkable progress has led to a new name and expanded mission for the center. MARCC has become ARCH, short for Advanced Research Computing at Hopkins. The reimagined and expanded facility is designed to sustain advanced and data-intensive computing growth with a goal of enabling innovative, dynamic, and life-improving.

“ARCH’s basic philosophy is to create and sustain a welcoming place for high-performance computing that will provide resources to foster a collaborative community of researchers in computational science and engineering. Rather than being a siloed collection of clusters for individual PIs, the genius of ARCH is that we pool our resources,” says Paulette Clancy, head of the Department of Chemical and Biomolecular Engineering and chair of the Hopkins Research Computing Committee, the faculty oversight group for ARCH.

An innovative feature of the expanded and reimagined facility is this “fair-share” approach which Clancy says allows ARCH to balance the load and need for computing resources at any given time.

“This rather egalitarian philosophy allows you to use my computing cluster when I don’t need it, and vice versa, maximizing job throughput,” Clancy says, pointing out that this method offers improved economies of scale. “Cooling, power, and system administration are all co-located into one resource.”

ARCH’s business model is configured so that the funds necessary to provide ongoing hardware support for facility will be provided in perpetuity by participating schools and researchers, ensuring that the facility can offer reliable high-quality service and maintains a “future-ready” stance. In fact, the hardware that forms the computing heart of the facility will need to change roughly every five years.

ARCH’s current computing cluster, named “Rockfish,” was the result of a large National Science Foundation Major Research Instrumentation (MRI) (US) program grant that was used to refresh MARCC’s computational hardware, ramping up its capabilities. That award also let MARCC (the nascent ARCH) become a member of NSF’s Extreme Science and Engineering Discovery Experiment network, through which scientists across the nation interactively share expertise, data, and computing resources.

Like MARCC, ARCH is structured on a model called “condo computing,” in which users buy their own nodes and have them installed in a central cluster. Researchers then not only have priority access to the resources they purchased, but also to those of other researchers in the cluster, if those are not being used.

“Envision Rockfish as a leasing office connected to any number of smaller nearby buildings—condos—that all interact together,” explains Combariza, director of ARCH. “Any PI can purchase hardware compatible with Rockfish which will be integrated into the overall ARCH ‘resort.'”

Those condos, like their real-life real estate counterparts, rely on the infrastructure provided by MARCC and ARCH, but the PIs do not “own” them. They are available for high priority use by the researcher who purchased them. All condos become part of the shared pool of resources, providing better efficiency of use for all the ARCH user community, organizers say.

The result is something unique, according to Clancy.

“It is a community where the hardware and software that we share allows us to be greater than the sum of our PI parts,” she says.

ARCH management has plans to partner closely with Hopkins Institute for Data Intensive Engineering and Science, or IDIES, to facilitate a seamless process of data-sharing in a shared and shareable resource. For example, they envision that data, methods, and insights created in individual labs connected to ARCH to someday be shared with physicians in clinics and medical centers to improve patient care.

“We see ARCH becoming a critical resource to initiatives here at Hopkins that are developing and applying AI and machine learning to improve the lives of people on our fragile planet,” Clancy says.

The advent of ARCH also brings with it the first annual High Performance Computing symposium, to be held in the late fall. Details will be forthcoming once the semester begins, but organizers envision that this will grow into an annual, high-profile event attracting top talent in high-performance computing.

“We envision the HPC symposium becoming a visible and acclaimed annual event that allows students, staff, faculty, visitors, industry representatives, non-profits, etc., to see what’s new and exciting in the world of HPC,” Clancy says.

See the full article here.

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

Driven by the pursuit of excellence, the University of Maryland (US) has enjoyed a remarkable rise in accomplishment and reputation over the past two decades. By any measure, Maryland is now one of the nation’s preeminent public research universities and on a path to become one of the world’s best. To fulfill this promise, we must capitalize on our momentum, fully exploit our competitive advantages, and pursue ambitious goals with great discipline and entrepreneurial spirit. This promise is within reach. This strategic plan is our working agenda.

The plan is comprehensive, bold, and action oriented. It sets forth a vision of the University as an institution unmatched in its capacity to attract talent, address the most important issues of our time, and produce the leaders of tomorrow. The plan will guide the investment of our human and material resources as we strengthen our undergraduate and graduate programs and expand research, outreach and partnerships, become a truly international center, and enhance our surrounding community.

Our success will benefit Maryland in the near and long term, strengthen the State’s competitive capacity in a challenging and changing environment and enrich the economic, social and cultural life of the region. We will be a catalyst for progress, the State’s most valuable asset, and an indispensable contributor to the nation’s well-being. Achieving the goals of Transforming Maryland requires broad-based and sustained support from our extended community. We ask our stakeholders to join with us to make the University an institution of world-class quality with world-wide reach and unparalleled impact as it serves the people and the state of Maryland.

About the Hub
We’ve been doing some thinking — quite a bit, actually — about all the things that go on at Johns Hopkins. Discovering the glue that holds the universe together, for example. Or unraveling the mysteries of Alzheimer’s disease. Or studying butterflies in flight to fine-tune the construction of aerial surveillance robots. Heady stuff, and a lot of it.

In fact, Johns Hopkins does so much, in so many places, that it’s hard to wrap your brain around it all. It’s too big, too disparate, too far-flung.

We created the Hub to be the news center for all this diverse, decentralized activity, a place where you can see what’s new, what’s important, what Johns Hopkins is up to that’s worth sharing. It’s where smart people (like you) can learn about all the smart stuff going on here.

At the Hub, you might read about cutting-edge cancer research or deep-trench diving vehicles or bionic arms. About the psychology of hoarders or the delicate work of restoring ancient manuscripts or the mad motor-skills brilliance of a guy who can solve a Rubik’s Cube in under eight seconds.

There’s no telling what you’ll find here because there’s no way of knowing what Johns Hopkins will do next. But when it happens, this is where you’ll find it.

Johns Hopkins University campus

The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

The Johns Hopkins University (US) is a private research university in Baltimore, Maryland. Founded in 1876, the university was named for its first benefactor, the American entrepreneur and philanthropist Johns Hopkins. His $7 million bequest (approximately $147.5 million in today’s currency)—of which half financed the establishment of the Johns Hopkins Hospital—was the largest philanthropic gift in the history of the United States up to that time. Daniel Coit Gilman, who was inaugurated as the institution’s first president on February 22, 1876, led the university to revolutionize higher education in the U.S. by integrating teaching and research. Adopting the concept of a graduate school from Germany’s historic Ruprecht Karl University of Heidelberg, [Ruprecht-Karls-Universität Heidelberg] (DE), Johns Hopkins University is considered the first research university in the United States. Over the course of several decades, the university has led all U.S. universities in annual research and development expenditures. In fiscal year 2016, Johns Hopkins spent nearly $2.5 billion on research. The university has graduate campuses in Italy, China, and Washington, D.C., in addition to its main campus in Baltimore.

Johns Hopkins is organized into 10 divisions on campuses in Maryland and Washington, D.C., with international centers in Italy and China. The two undergraduate divisions, the Zanvyl Krieger School of Arts and Sciences and the Whiting School of Engineering, are located on the Homewood campus in Baltimore’s Charles Village neighborhood. The medical school, nursing school, and Bloomberg School of Public Health, and Johns Hopkins Children’s Center are located on the Medical Institutions campus in East Baltimore. The university also consists of the Peabody Institute, Applied Physics Laboratory, Paul H. Nitze School of Advanced International Studies, School of Education, Carey Business School, and various other facilities.

Johns Hopkins was a founding member of the American Association of Universities (US). As of October 2019, 39 Nobel laureates and 1 Fields Medalist have been affiliated with Johns Hopkins. Founded in 1883, the Blue Jays men’s lacrosse team has captured 44 national titles and plays in the Big Ten Conference as an affiliate member as of 2014.

Research

The opportunity to participate in important research is one of the distinguishing characteristics of Hopkins’ undergraduate education. About 80 percent of undergraduates perform independent research, often alongside top researchers. In FY 2013, Johns Hopkins received $2.2 billion in federal research grants—more than any other U.S. university for the 35th consecutive year. Johns Hopkins has had seventy-seven members of the Institute of Medicine, forty-three Howard Hughes Medical Institute Investigators, seventeen members of the National Academy of Engineering, and sixty-two members of the National Academy of Sciences. As of October 2019, 39 Nobel Prize winners have been affiliated with the university as alumni, faculty members or researchers, with the most recent winners being Gregg Semenza and William G. Kaelin.

Between 1999 and 2009, Johns Hopkins was among the most cited institutions in the world. It attracted nearly 1,222,166 citations and produced 54,022 papers under its name, ranking No. 3 globally [after Harvard University (US) and the Max Planck Society (DE)] in the number of total citations published in Thomson Reuters-indexed journals over 22 fields in America.

In FY 2000, Johns Hopkins received $95.4 million in research grants from the National Aeronautics and Space Administration (US), making it the leading recipient of NASA research and development funding. In FY 2002, Hopkins became the first university to cross the $1 billion threshold on either list, recording $1.14 billion in total research and $1.023 billion in federally sponsored research. In FY 2008, Johns Hopkins University performed $1.68 billion in science, medical and engineering research, making it the leading U.S. academic institution in total R&D spending for the 30th year in a row, according to a National Science Foundation (US) ranking. These totals include grants and expenditures of JHU’s Applied Physics Laboratory in Laurel, Maryland.

The Johns Hopkins University also offers the “Center for Talented Youth” program—a nonprofit organization dedicated to identifying and developing the talents of the most promising K-12 grade students worldwide. As part of the Johns Hopkins University, the “Center for Talented Youth” or CTY helps fulfill the university’s mission of preparing students to make significant future contributions to the world. The Johns Hopkins Digital Media Center (DMC) is a multimedia lab space as well as an equipment, technology and knowledge resource for students interested in exploring creative uses of emerging media and use of technology.

In 2013, the Bloomberg Distinguished Professorships program was established by a $250 million gift from Michael Bloomberg. This program enables the university to recruit fifty researchers from around the world to joint appointments throughout the nine divisions and research centers. Each professor must be a leader in interdisciplinary research and be active in undergraduate education. Directed by Vice Provost for Research Denis Wirtz, there are currently thirty two Bloomberg Distinguished Professors at the university, including three Nobel Laureates, eight fellows of the American Association for the Advancement of Science (US), ten members of the American Academy of Arts and Sciences, and thirteen members of the National Academies.

From University of Maryland (US) : “Unconventional Superconductor Acts the Part of a Promising Quantum Computing Platform”

From University of Maryland (US)

July 15 2021

Scientists on the hunt for an unconventional kind of superconductor have produced the most compelling evidence to date that they’ve found one. In a pair of papers, researchers at the University of Maryland’s (UMD) Quantum Materials Center (QMC) and colleagues have shown that uranium ditelluride (or UTe2 for short) displays many of the hallmarks of a topological superconductor—a material that may unlock new ways to build quantum computers and other futuristic devices.

“Nature can be wicked,” says Johnpierre Paglione, a professor of physics at UMD, the director of QMC and senior author on one of the papers. “There could be other reasons we’re seeing all this wacky stuff, but honestly, in my career, I’ve never seen anything like it.”

All superconductors carry electrical currents without any resistance. It’s kind of their thing. The wiring behind your walls can’t rival this feat, which is one of many reasons that large coils of superconducting wires and not normal copper wires have been used in MRI machines and other scientific equipment for decades.

Crystals of a promising topological superconductor grown by researchers at the University of Maryland’s Quantum Materials Center. (Credit: Sheng Ran/NIST).

But superconductors achieve their super-conductance in different ways. Since the early 2000s scientists have been looking for a special kind of superconductor-one that relies on an intricate choreography of the subatomic particles that actually carry its current.

This choreography has a surprising director: a branch of mathematics called topology. Topology is a way of grouping together shapes that can be gently transformed into one another through pushing and pulling. For example, a ball of dough can be shaped into a loaf of bread or a pizza pie, but you can’t make it into a donut without poking a hole in it. The upshot is that, topologically speaking, a loaf and a pie are identical, while a donut is different. In a topological superconductor, electrons perform a dance around each other while circling something akin to the hole in the center of a donut.

Unfortunately, there’s no good way to slice a superconductor open and zoom in on these electronic dance moves. At the moment, the best way to tell whether or not electrons are boogieing on an abstract donut is to observe how a material behaves in experiments. Until now, no superconductor has been conclusively shown to be topological, but the new papers show that UTe2 looks, swims and quacks like the right kind of topological duck.

One study, by Paglione’s team in collaboration with the group of Aharon Kapitulnik at Stanford University (US), reveals that not one but two kinds of superconductivity exist simultaneously in UTe2. Using this result, as well as the way light is altered when it bounces off the material (in addition to previously published experimental evidence), they were able to narrow down the types of superconductivity that are present to two options, both of which theorists believe are topological. They published their findings on July 15, 2021, in the journal Science.

In another study, a team led by Steven Anlage, a professor of physics at UMD and a member of QMC, revealed unusual behavior on the surface of the same material. Their findings are consistent with the long-sought-after phenomenon of topologically protected Majorana modes. Majorana modes-exotic particles that behave a bit like half of an electron-are predicted to arise on the surface of topological superconductors. These particles particularly excite scientists because they might be a foundation for robust quantum computers. Anlage and his team reported their results in a paper published May 21, 2021 in the journal Nature Communications.

Superconductors only reveal their special characteristics below a certain temperature, much like water only freezes below zero Celsius. In normal superconductors, electrons pair up into a two-person conga line, following each other through the metal. But in some rare cases, the electron couples perform a circular dance around each other, more akin to a waltz. The topological case is even more special—the circular dance of the electrons contains a vortex, like the eye amidst the swirling winds of a hurricane. Once electrons pair up in this way, the vortex is hard to get rid of, which is what makes a topological superconductor distinct from one with a simple, fair-weather electron dance.

Back in 2018, Paglione’s team, in collaboration with the team of Nicholas Butch, an adjunct associate professor of physics at UMD and a physicist at the National Institute of Standards and Technology (NIST) (US), unexpectedly discovered that UTe2 was a superconductor. Right away, it was clear that it wasn’t your average superconductor. Most notably, it seemed unphased by large magnetic fields, which normally destroy superconductivity by splitting up the electron dance couples. This was the first clue that the electron pairs in UTe2 hold onto each other more tightly than usual, likely because their paired dance is circular. This garnered a lot of interest and further research from others in the field.

“It’s kind of like a perfect storm superconductor,” says Anlage. “It’s combining a lot of different things that no one’s ever seen combined before.”

In the new Science paper, Paglione and his collaborators reported two new measurements that reveal the internal structure of UTe2. The UMD team measured the material’s specific heat, which characterizes how much energy it takes to heat it up by one degree. They measured the specific heat at different starting temperatures and watched it change as the sample became superconducting.

“Normally there’s a big jump in specific heat at the superconducting transition,” says Paglione. “But we see that there’s actually two jumps. So that’s evidence of actually two superconducting transitions, not just one. And that’s highly unusual.”

The two jumps suggested that electrons in UTe2 can pair up to perform either of two distinct dance patterns.

In a second measurement, the Stanford team shone laser light onto a piece of UTe2 and noticed that the light reflecting back was a bit twisted. If they sent in light bobbing up and down, the reflected light bobbed mostly up and down but also a bit left and right. This meant something inside the superconductor was twisting up the light and not untwisting it on its way out.

Kapitulnik’s team at Stanford also found that a magnetic field could coerce UTe2 into twisting light one way or the other. If they applied a magnetic field pointing up as the sample became superconducting, the light coming out would be tilted to the left. If they pointed the magnetic field down, the light tilted to the right. This told that researchers that, for the electrons dancing inside the sample, there was something special about the up and down directions of the crystal.

To sort out what all this meant for the electrons dancing in the superconductor, the researchers enlisted the help of Daniel F. Agterberg, a theorist and professor of physics at the University of Wisconsin-Milwaukee (US) and a co-author of the Science paper. According to the theory, the way uranium and tellurium atoms are arranged inside the UTe2 crystal allows electron couples to team up in eight different dance configurations. Since the specific heat measurement shows that two dances are going on at the same time, Agterberg enumerated all the different ways to pair these eight dances together. The twisted nature of the reflected light and the coercive power of a magnetic field along the up-down axis cut the possibilities down to four. Previous results showing the robustness of UTe2’s superconductivity under large magnetic fields further constrained it to only two of those dance pairs, both of which form a vortex and indicate a stormy, topological dance.

“What’s interesting is that given the constraints of what we’ve seen experimentally, our best theory points to a certainty that the superconducting state is topological,” says Paglione.

If the nature of superconductivity in a material is topological, the resistance will still go to zero in the bulk of the material, but on the surface something unique will happen: Particles, known as Majorana modes, will appear and form a fluid that is not a superconductor. These particles also remain on the surface despite defects in the material or small disruptions from the environment. Researchers have proposed that, thanks to the unique properties of these particles, they might be a good foundation for quantum computers. Encoding a piece of quantum information into several Majoranas that are far apart makes the information virtually immune to local disturbances that, so far, have been the bane of quantum computers.

Anlage’s team wanted to probe the surface of UTe2 more directly to see if they could spot signatures of this Majorana sea. To do that, they sent microwaves towards a chunk UTe2, and measured the microwaves that came out on the other side. They compared the output with and without the sample, which allowed them to test properties of the bulk and the surface simultaneously.

The surface leaves an imprint on the strength of the microwaves, leading to an output that bobs up and down in sync with the input, but slightly subdued. But since the bulk is a superconductor, it offers no resistance to the microwaves and doesn’t change their strength. Instead, it slows them down, causing delays that make the output bob up and down out of sync with the input. By looking at the out-of-sync parts of the response, the researchers determined how many of the electrons inside the material participate in the paired dance at various temperatures. They found that the behavior agreed with the circular dances suggested by Paglione’s team.

­­­Perhaps more importantly, the in-sync part of the microwave response showed that the surface of UTe2 isn’t superconducting. This is unusual, since superconductivity is usually contagious: Putting a regular metal close to a superconductor spreads superconductivity to the metal. But the surface of UTe2 didn’t seem to catch superconductivity from the bulk—just as expected for a topological superconductor—and instead responded to the microwaves in a way that hasn’t been seen before.

“The surface behaves differently from any superconductor we’ve ever looked at,” Anlage says. “And then the question is ‘What’s the interpretation of that anomalous result?’ And one of the interpretations, which would be consistent with all the other data, is that we have this topologically protected surface state that is kind of like a wrapper around the superconductor that you can’t get rid of.”

It might be tempting to conclude that the surface of UTe2 is covered with a sea of Majorana modes and declare victory. However, extraordinary claims require extraordinary evidence. Anlage and his group have tried to come up with every possible alternative explanation for what they were observing and systematically ruled them out, from oxidization on the surface to light hitting the edges of the sample. Still, it is possible a surprising alternative explanation is yet to be discovered.

“In the back of your head you’re always thinking ‘Oh, maybe it was cosmic rays’, or ‘Maybe it was something else,’” says Anlage. “You can never 100% eliminate every other possibility.”

For Paglione’s part, he says the smoking gun will be nothing short of using surface Majorana modes to perform a quantum computation. However, even if the surface of UTe2 truly has a bunch of Majorana modes, there’s currently no straightforward way to isolate and manipulate them. Doing so might be more practical with a thin film of UTe2 instead of the (easier to produce) crystals that were used in these recent experiments.

“We have some proposals to try to make thin films,” Paglione says. “Because it’s uranium and it’s radioactive, it requires some new equipment. The next task would be to actually try to see if we can grow films. And then the next task would be to try to make devices. So that would require several years, but it’s not crazy.”

Whether UTe2 proves to be the long-awaited topological superconductor or just a pigeon that learned to swim and quack like a duck, both Paglione and Anlage are excited to keep finding out what the material has in store.

“It’s pretty clear though that there’s a lot of cool physics in the material,” Anlage says. “Whether or not it’s Majoranas on the surface is certainly a consequential issue, but it’s exploring novel physics which is the most exciting stuff.”

See the full article here.

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

Driven by the pursuit of excellence, the University of Maryland (US) has enjoyed a remarkable rise in accomplishment and reputation over the past two decades. By any measure, Maryland is now one of the nation’s preeminent public research universities and on a path to become one of the world’s best. To fulfill this promise, we must capitalize on our momentum, fully exploit our competitive advantages, and pursue ambitious goals with great discipline and entrepreneurial spirit. This promise is within reach. This strategic plan is our working agenda.

The plan is comprehensive, bold, and action oriented. It sets forth a vision of the University as an institution unmatched in its capacity to attract talent, address the most important issues of our time, and produce the leaders of tomorrow. The plan will guide the investment of our human and material resources as we strengthen our undergraduate and graduate programs and expand research, outreach and partnerships, become a truly international center, and enhance our surrounding community.

Our success will benefit Maryland in the near and long term, strengthen the State’s competitive capacity in a challenging and changing environment and enrich the economic, social and cultural life of the region. We will be a catalyst for progress, the State’s most valuable asset, and an indispensable contributor to the nation’s well-being. Achieving the goals of Transforming Maryland requires broad-based and sustained support from our extended community. We ask our stakeholders to join with us to make the University an institution of world-class quality with world-wide reach and unparalleled impact as it serves the people and the state of Maryland.

From University of Maryland (US) via phys.org : “New research adds a wrinkle to our understanding of the origins of matter in the Milky Way”

From University of Maryland (US)

via

phys.org

NASA JPL-Caltech(US) Milky Way R. Hurt. The bar is visible in this image.

New findings published this week in Physical Review Letters suggest that carbon, oxygen, and hydrogen cosmic rays travel through the galaxy toward Earth in a similar way, but, surprisingly, that iron arrives at Earth differently. Learning more about how cosmic rays move through the galaxy helps address a fundamental, lingering question in astrophysics: How is matter generated and distributed across the universe?

“So what does this finding mean?” asks John Krizmanic, a senior scientist with UMBC’s Center for Space Science and Technology (CSST). “These are indicators of something interesting happening. And what that something interesting is we’re going to have to see.”

Cosmic rays are atomic nuclei—atoms stripped of their electrons—that are constantly whizzing through space at nearly the speed of light. They enter Earth’s atmosphere at extremely high energies. Information about these cosmic rays can give scientists clues about where they came from in the galaxy and what kind of event generated them.

Cosmic rays produced by high-energy astrophysics sources ASPERA collaboration AStroParticle ERAnet

An instrument on the International Space Station (ISS) called the Calorimetric Electron Telescope (CALET) has been collecting data about cosmic rays since 2015.

CALET Overview CALorimetric Electron Telescope (CALET) is an astrophysics mission that searches for signatures of dark matter and provides the highest energy direct measurements of the cosmic ray electron spectrum in order to observe discrete sources of high energy particle acceleration in our local region of the Galaxy. Credit: National Aeronautics Space Agency (US), Japan Aerospace Exploration Agency [ (国立研究開発法人宇宙航空研究開発機構] (JP) JAXA, Italian Space Agency A.S.I. – [Agenzia Spaziale Italiana] (IT).

The data include details such as how many and what kinds of atoms are arriving, and how much energy they’re arriving with. The American, Italian, and Japanese teams that manage CALET, including UMBC’s Krizmanic and postdoc Nick Cannady, collaborated on the new research.

Iron on the move

Cosmic rays arrive at Earth from elsewhere in the galaxy at a huge range of energies—anywhere from 1 billion volts to 100 billion billion volts. The CALET instrument is one of extremely few in space that is able to deliver fine detail about the cosmic rays it detects. A graph called a cosmic ray spectrum shows how many cosmic rays are arriving at the detector at each energy level. The spectra for carbon, oxygen, and hydrogen cosmic rays are very similar, but the key finding from the new paper is that the spectrum for iron is significantly different.

There are several possibilities to explain the differences between iron and the three lighter elements. The cosmic rays could accelerate and travel through the galaxy differently, although scientists generally believe they understand the latter, Krizmanic says.

“Something that needs to be emphasized is that the way the elements get from the sources to us is different, but it may be that the sources are different as well,” adds Michael Cherry, physics professor emeritus at Louisiana State University (LSU) (US) and a co-author on the new paper. Scientists generally believe that cosmic rays originate from exploding stars (supernovae), but neutron stars or very massive stars could be other potential sources.

Next-level precision

An instrument like CALET is important for answering questions about how cosmic rays accelerate and travel, and where they come from. Instruments on the ground or balloons flown high in Earth’s atmosphere were the main source of cosmic ray data in the past. But by the time cosmic rays reach those instruments, they have already interacted with Earth’s atmosphere and broken down into secondary particles. With Earth-based instruments, it is nearly impossible to identify precisely how many primary cosmic rays and which elements are arriving, plus their energies. But CALET, being on the ISS above the atmosphere, can measure the particles directly and distinguish individual elements precisely.

Iron is a particularly useful element to analyze, explains Cannady, a postdoc with CSST and a former Ph.D. student with Cherry at LSU. On their way to Earth, cosmic rays can break down into secondary particles, and it can be hard to distinguish between original particles ejected from a source (like a supernova) and secondary particles. That complicates deductions about where the particles originally came from.

“As things interact on their way to us, then you’ll get essentially conversions from one element to another,” Cannady says. “Iron is unique, in that being one of the heaviest things that can be synthesized in regular stellar evolution, we’re pretty certain that it is pretty much all primary cosmic rays. It’s the only pure primary cosmic ray, where with others you’ll have some secondary components feeding into that as well.”

“Made of stardust”

Measuring cosmic rays gives scientists a unique view into high-energy processes happening far, far away. The cosmic rays arriving at CALET represent “the stuff we’re made of. We are made of stardust,” Cherry says. “And energetic sources, things like supernovas, eject that material from their interiors, out into the galaxy, where it’s distributed, forms new planets, solar systems, and… us.”

“The study of cosmic rays is the study of how the universe generates and distributes matter, and how that affects the evolution of the galaxy,” Krizmanic adds. “So really it’s studying the astrophysics of this engine we call the Milky Way that’s throwing all these elements around.”

A global effort

The Japanese space agency launched CALET and today leads the mission in collaboration with the U.S. and Italian teams. In the U.S., the CALET team includes researchers from LSU; NASA Goddard Space Flight Center (US); UMBC; University of Maryland, College Park; University of Denver (US); and Washington University.The new paper is the fifth from this highly successful international collaboration published in PRL, one of the most prestigious physics journals.

CALET was optimized to detect cosmic ray electrons, because their spectrum can contain information about their sources. That’s especially true for sources that are relatively close to Earth in galactic terms: within less than one-thirtieth the distance across the Milky Way. But CALET also detects the atomic nuclei of cosmic rays very precisely. Now those nuclei are offering important insights about the sources of cosmic rays and how they got to Earth.

“We didn’t expect that the nuclei—the carbon, oxygen, protons, iron—would really start showing some of these detailed differences that are clearly pointing at things we don’t know,” Cherry says.

The latest finding creates more questions than it answers, emphasizing that there is still more to learn about how matter is generated and moves around the galaxy. “That’s a fundamental question: How do you make matter?” Krizmanic says. But, he adds, “That’s the whole point of why we went in this business, to try to understand more about how the universe works.”

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

Driven by the pursuit of excellence, the University of Maryland (US) has enjoyed a remarkable rise in accomplishment and reputation over the past two decades. By any measure, Maryland is now one of the nation’s preeminent public research universities and on a path to become one of the world’s best. To fulfill this promise, we must capitalize on our momentum, fully exploit our competitive advantages, and pursue ambitious goals with great discipline and entrepreneurial spirit. This promise is within reach. This strategic plan is our working agenda.

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From American Institute of Physics-AIP (US) via phys.org : “Boosting fiber optics communications with advanced quantum-enhanced receiver”

From American Institute of Physics-AIP (US)

via

phys.org

April 20, 2021

Illustration showing how single-photon detection is used for feedback. Once correct parameters for the reference beam are established, the input state is extinguished. Credit: Ivan Burenkov.

Fiber optic technology is the holy grail of high-speed, long-distance telecommunications. Still, with the continuing exponential growth of internet traffic, researchers are warning of a capacity crunch.

In AVS Quantum Science, researchers from the National Institute of Standards and Technology (US) and the University of Maryland (US) show how quantum-enhanced receivers could play a critical role in addressing this challenge.

The scientists developed a method to enhance receivers based on quantum physics properties to dramatically increase network performance while significantly reducing the error bit rate (EBR) and energy consumption.

Fiber optic technology relies on receivers to detect optical signals and convert them into electrical signals. The conventional detection process, largely as a result of random light fluctuations, produces ‘shot noise,’ which decreases detection ability and increases EBR.

To accommodate this problem, signals must continually be amplified as pulsating light becomes weaker along the optic cable, but there is a limit to maintaining adequate amplification when signals become barely perceptible.

Quantum-enhanced receivers that process up to two bits of classical information and can overcome the shot noise have been demonstrated to improve detection accuracy in laboratory environments. In these and other quantum receivers, a separate reference beam with a single-photon detection feedback is used so the reference pulse eventually cancels out the input signal to eliminate the shot noise.

The researchers’ enhanced receiver, however, can decode as many as four bits per pulse, because it does a better job in distinguishing among different input states.

To accomplish more efficient detection, they developed a modulation method and implemented a feedback algorithm that takes advantage of the exact times of single photon detection. Still, no single measurement is perfect, but the new holistically designed communication system yields increasingly more accurate results on average.

“We studied the theory of communications and the experimental techniques of quantum receivers to come up with a practical telecommunication protocol that takes maximal advantage of the quantum measurement,” author Sergey Polyakov said. “With our protocol, because we want the input signal to contain as few photons as possible, we maximize the chance that the reference pulse updates to the right state after the very first photon detection, so at the end of the measurement, the EBR is minimized.”

See the full article here.

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Stem Education Coalition

The American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corporate headquarters are at the American Center for Physics in College Park, Maryland, but the institute also has offices in Melville, New York, and Beijing.

The focus of the AIP appears to be organized around a set of core activities. The first delineated activity is to support member societies regarding essential society functions. This is accomplished by annually convening the various society officers to discuss common areas of concern. A range of topics is discussed which includes scientific publishing, public policy issues, membership-base issues, philanthropic giving, science education, science careers for a diverse population, and a forum for sharing ideas.

Another core activity is publishing the science of physics in research journals, magazines, and conference proceedings. Member societies continue nevertheless to publish their own journals.

Other core activities are tracking employment and education trends with six decades of coverage, being a liaison between research science and industry, historical collections and physics outreach programs, and supporting science education initiatives and supporting undergraduate physics. One other core activity is as an advocate for science policy to the U.S. Congress and the general public.

Member societies:
Acoustical Society of America
American Association of Physicists in Medicine
American Association of Physics Teachers
American Astronomical Society
American Crystallographic Association
American Meteorological Society
American Physical Society
American Vacuum Society

Affiliated societies

American Association for the Advancement of Science, Section on Physics
American Chemical Society, Division of Physical Chemistry
American Institute of Aeronautics and Astronautics
American Nuclear Society
American Society of Civil Engineers
ASM International
Astronomical Society of the Pacific
Biomedical Engineering Society
Council on Undergraduate Research, Physics & Astronomy Division
Electrochemical Society
Geological Society of America
IEEE Nuclear and Plasma Sciences Society
International Association of Mathematical Physics
International Union of Crystallography
International Centre for Diffraction Data
Health Physics Society