From Brookhaven National Lab & Cornell University: “Innovative Accelerator Achieves Full Energy Recovery”

From Brookhaven National Lab

September 10, 2019
Karen McNulty Walsh
kmcnulty@bnl.gov

Collaborative Cornell University/Brookhaven Lab project known as CBETA offers promise for future accelerator applications.

Brookhaven Lab members of the CBETA team with Laboratory Director Doon Gibbs, front row, right.

An innovative particle accelerator designed and built by scientists from the U.S. Department of Energy’s Brookhaven National Laboratory and Cornell University has achieved a significant milestone that could greatly enhance the efficiency of future particle accelerators. After sending a particle beam for one pass through the accelerator, machine components recovered nearly all of the energy required for accelerating the particles. This recovered energy can then be used for the next stage of acceleration—to accelerate another batch of particles—thus greatly reducing the potential cost of accelerating particles to high energies.

“No new power is required to maintain the radiofrequency (RF) fields in the RF cavities used for acceleration, because the accelerated beam deposits its energy in the RF cavities when it is decelerated,” said Brookhaven Lab accelerator physicist Dejan Trbojevic, who led the design and construction of key components for the project and serves as the Principal Investigator for Brookhaven’s contributions.

The prototype accelerator—known as the Cornell-Brookhaven ERL Test Accelerator (CBETA), where ERL stands for “energy-recovery linac”—was built at Cornell with funding from Brookhaven Science Associates (the managing entity of Brookhaven Lab) and the New York State Energy Research and Development Authority (NYSERDA) as a research and development project in support of a possible future nuclear physics facility, the Electron-Ion Collider (EIC). The energy-recovery approach could play an essential role in generating reusable electron beams for enhancing operations at a future EIC. The electrons would reduce the spread of ion beams in the EIC, thus increasing the number of particle collisions scientists can record to make physics discoveries.

Schematic of the CBETA energy recovery linac installed at Cornell University. Electrons produced by a direct-current (DC) photo-emitter electron source are transported by a high-power superconducting radiofrequency (SRF) injector linac into the high-current main linac cryomodule, where SRF cavities accelerate them to high energy before sending them around the racetrack-shaped accelerator. Each curved arc is made of a series of fixed field, alternating gradient (FFA) permanent magnets. After passing through the second FFA arc, the electrons re-enter the main linac cryomodule, which decelerates them and returns their energy to the RF cavities so it can be used again.

In designing and executing this project, the Brookhaven team drew on its vast experience of improving the performance of the Relativistic Heavy Ion Collider (RHIC), a DOE Office of Science user facility for nuclear physics research.

BNL/RHIC

The accelerator technologies being developed for the EIC would push beyond the capabilities at RHIC and open up a new frontier in nuclear physics.

The injector and main linac cryomodule.

Tech specs

CBETA consists of a direct-current (DC) photo-emitter electron source that creates the electron beams to be accelerated. These electrons pass through a high-power superconducting radiofrequency (SRF) injector linac that transports them into a high-current main linac cryomodule (MLC). There, six SRF cavities accelerate the electrons to high energy, sending them around the racetrack-shaped accelerator. Each curved section of the racetrack is a single arc of permanent magnets designed with fixed-field alternating-gradient (FFA) optics that allow a single vacuum tube to accommodate beams at four different energies at the same time. After passing through the second FFA arc, the electrons re-enter the MLC, which has been uniquely optimized to decelerate the particles after a single pass and return their energy to the RF cavities so it can be used again.

When completed, CBETA will accelerate particles through four complete turns, adding energy with each pass—all of which will be recovered during deceleration after the beams have been used. This will make it the world’s first four-turn superconducting radiofrequency ERL.

Many scientists and engineers at Brookhaven Lab contributed to the design and construction of the magnets and other components of the accelerator, as well as the electronic devices that monitor the positions of the accelerated and decelerated beams: Francois Meot, Scott Berg, Stephen Brooks, and Nicholaos Tsoupas drove the design of the ERL’s optics; Brookhaven physicists led by Brooks and George Mahler designed, built, measured, and applied corrections to the permanent magnets; and Rob Michnoff led the design and construction of the beam position monitor system.

“After building and successfully testing prototypes of the magnets, we established a very successful collaboration with Cornell, led by Principal Investigator Georg Hoffstaetter, to build the ERL using the refined fixed-field magnet designs,” Trbojevic said.

Cornell provided the DC electron injector—the world’s record holder for producing high intensity, low emittance electron beams—which they recommissioned for the CBETA project. A team of young scientists and graduate students, including Adam Bartnik, Colwyn Gulliford, Kirsten Deitrick, and Nilanjan Banerjee, made other essential contributions: successfully commissioning the main linac cryomodule, and preparing the “command scripts”—computer-driven instructions—for running and commissioning the ERL in collaboration with Berg and other Brookhaven physicists.

Part of one of the fixed field, alternating gradient (FFA) permanent magnet arcs.

“We hold weekly internet-based collaboration meetings and we had several visits and meetings at Cornell to ensure that the project was reaching the key milestones and that installation was proceeding according to the schedule,” said Michnoff, the Brookhaven Lab project manager.

In May 2019, the team sent an electron beam with an energy of 42 million electron volts (MeV) through the FFA return loop for the first time. The beam made it through all 200 permanent magnets without the need for a single correction. In early June 2019, an energy scan in the FFA loop showed that the return beamline transported particles of different energies superbly, agreeing very well with the expectations for the design.

Next, on June 13, the beam was accelerated to 42 MeV, transported through the FFA return loop back to the MLC, where the electrons were decelerated from 42 MeV back to the injection energy of 6 MeV, with the rest of their energy transferred back into the six SRF cavities of the main linac. And on June 24, the CBETA team achieved full energy recovery for the first time—demonstrating that each cavity could accelerate electrons on their second pass through the MLC without requiring additional external power.

“Each cavity successfully regained the energy it expended in beam acceleration, eliminating or dramatically reducing the power needed to accelerate electrons,” Trbojevic said.

“The successful demonstration of single-turn energy recovery shows that we are on the path toward creating this first-of-its-kind facility,” Trbojevic said. “The entire team is committed and excited to complete this four-turn energy-recovery linac—one of the most interesting and innovative accelerator physics project in the world today.”

From Cornell University

CORNELL LABORATORY FOR ACCELERATOR-BASED SCIENCES AND EDUCATION — CLASSE

Update on Beam Commissioning

Cornell physicists, working with Brookhaven National Lab, are constructing a new type of particle accelerator called CBETA at Cornell’s Wilson Lab. This Energy Recovery Linac (ERL) is a test accelerator built with permanent magnets as well as electro magnets.

How it works: CBETA will recirculate multiple beams of different energies around the accelerator at one time. The electrons will make four accelerating passes around the accelerator, while building up energy as they pass through a cryomodule with superconducting RF (SRF) accelerating structures. In four more passes, they will return to the superconducting cavities that accelerated them and return their energy back to these cavities – hence it is an Energy Recovery Linac (ERL). While this method conserves energy, it also creates beams that are tightly bound and are a factor of 1,000 times brighter than other sources. For more details, please contact the Cornell PI Prof. Georg Hoffstaetter.

Although linear accelerators (Linac) can have superior beam densities when compared to large circular accelerators, they are exceedingly wasteful due to the beam being discarded after use and can therefore only have an extremely low current compared to ring accelerators. This means that the amount of data collected in one hour in a circular accelerator may take several years to collect in a linear accelerator. In an ERL, the energy is recovered, and the beam current can therefore be as large as in a circular accelerator while its beam density remains as large as in a Linac.

CBETA: the first multi-turn SRF ERL

The lynchpin of CBETA’s design is to repeat the acceleration in a SRF cavities four times by recirculating multiple beams at four different energies. The beam with highest energy (150MeV) is to be used for experiments and is then decelerated in the same cavities four times to recapture the beam’s energies into the SRF cavities. Reusing the same cavity multiple times significantly reduces the construction and operational costs of the accelerator. It also means that an accelerator which would span roughly a foot ball field can fit into a single experimental Hall at Cornell’s Wilson Laboratory.

However, beams of different energies require different amounts of bending, in the same way that it is hard for your car to navigate a sharp bend at 100 miles per hour. Traditional magnet designs are simply unable to keep different beams on the same “track”. Instead, the CBETA design relies on cutting edge Fixed-Field Alternating Gradient (FFAG) magnets to contain all of the beams in a single 3 inch beam pipe. CBETA will be the first SRF ERL with more than one turn and it is also the first project in the history of accelerator physics to implement this new magnet technology in an Energy Recovery Linac.

The task of creating and controlling eight beams of four different energies in a single accelerating structure sounds daunting. But by leveraging the pre-existing infrastructure and experience of Cornell with the power and expertise of Brookhaven National Laboratory, it will soon become a reality.

Cornell University has prototyped technology essential for CBETA, including a DC gun and an SRF injector Linac with world-record current and normalized brightness in a bunch train, a high-current CW cryomodule for 70 MeV energy gain, a high-power beam stop, and several diagnostics tools for high-current and high-brightness beams, e.g. a beamline for measuring 6-D phase-space densities, a fast wire scanner for beam profiles, and beam loss diagnostics. All these now being used in the contrition of CBETA.

Within the next several years, CBETA will develop into a powerhouse of accelerator physics and technology, and will be one of the most advanced on the planet (earth). When this prototype ERL is complete and expanded upon, it will be a critical resource to New York State and the nation, propelling high-power accelerator science, enabling applications of many particle accelerators, from biomedical advancement to basic physics and from computer-chip lithography to material science, driving economic development.

CBETA is composed of 4 main parts:

-The Photoinjector that creates and prepares high-current electron beams to be injected into the Main Linac Cryomodule (MLC). The photoinjector in turn consists of a laser system that illuminates a photo-emitter cathode to produce electrons within a high-current DC electron source. These electrons traverses an emittance-matching section to produce a high-brightness beam which is then sent thorough the high-power injector cryomodule (ICM) for acceleration to the ERL’s injection energy.

-The Main Linac Cryomodule (MLC) that accelerates the beam through several passages and then decelerates the beam the same number of times to recapture its energy.

-The high-power Beam Stop where the electron beam is discarded after most of its energy has been recaptured.
4 Spreaders and 4 combiners with electro magnets that separate beams at 4 different energies after the MLC to match them into the FFAG return loop and then combine them again before re-entering the MLC.

-FFAG Magnets residing in the return loop. These cause very strong focusing so that beams with energies that differ by up to a factor 4 can be transported simultaneously.

Dominant funding for CBETA comes from NYSERDA (2016 to 2020). Important for this agency is that CBETA emphasizes energy savings by its use of energy recovery technology, its application of permanent magnets, and its particle acceleration by superconducting structures. Previous funding came from the NSF (2005 – 2015) for the development of the complete accelerator chain from the source to the main ERL accelerating module, from DOE supporting developments for the LCLS (2014-2015), and from the industrial company ASML (2015-2016) for applications in computer chip lithography.

See the full article here .

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One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

From insideHPC: “DOE Funds Argonne for better materials and chemistry through data science”

From insideHPC

September 10, 2019
Joseph E. Harmon at Argonne

The DOE Office of Science (Basic Energy Sciences) has announced that its Argonne National Laboratory will be receiving funding for two new projects that will use data science to accelerate discovery in chemistry and material sciences.

“Argonne is one of five national laboratories and fourteen universities awarded three-year grants under a DOE Funding Opportunity titled ​“Data Science for Discovery in Chemical and Materials Sciences.” Argonne was awarded funding for two research projects. Total funding will be nearly $4.75 million over three years.”

From left to right: (a) the raw data on the detector, (b) the diffuse scattering data after data reduction, (c) a machine learning-produced map showing extracted features, (d) the transform of the data, and (e) fits to the data at different temperatures. A project led by Ray Osborn (Materials Science division) will use data science to accomplish (c) and (d). (Image by Argonne National Laboratory.)

Lynda Soderholm, department head in the Chemical Sciences and Engineering division and Argonne Distinguished Fellow, leads one of Argonne’s new data science projects. Her collaborators include Stefan Wild and Prasanna Balaprakash from the Mathematics and Computer Science division and the Argonne Leadership Computing Facility, a DOE Office of Science User Facility, and Aurora Clark from Washington State University.

This team’s project entails a machine-learning approach to quantifying the energy drivers in chemical separations, such as liquid-liquid extraction, a common separation method. Chemical separations play a critical role in resource management by providing access to large quantities of resource-limited materials with high purity and enabling the cleanup of contaminated materials and chemicals for reuse. At present, molecular and mesoscale studies in chemical separations are limited to sampling of the reaction space by dividing the space into smaller, tractable problems. Recognizing the vastness and complexity of the reaction phase space, this project will turn to data science, machine learning and optimal design approaches to navigate the high-dimensional and interdependent features that define robust chemical separations.

Ray Osborn, senior physicist in the Materials Science division, is principal investigator for the other Argonne project. Collaborators include Stephan Rosenkranz from the Materials Science division, Charlotte Haley and Mihai Anitescu from the Mathematics and Computer Science division and Eun-Ah Kim and Kilian Weinberger from Cornell University.

“This team’s research is focused on quantum materials in which the coupling of electron spins to their orbital momenta is particularly strong. Researchers have predicted that this spin-orbit coupling generates exotic forms of cooperative electron ordering not seen before. By combining synchrotron X-ray capabilities with new computational methods utilizing machine learning and advanced spectral analysis, this research will reveal the ​“hidden order” in quantum materials and thereby elucidate the underlying interactions that would allow them to be harnessed in future applications as diverse as quantum computing, smart sensors and actuators, and low-power electronics.”

Both of these projects combine Argonne’s leadership in the chemical and materials sciences with Argonne’s expertise in data science, machine learning, and statistics. Both also involve collaborations with researchers in the Mathematics and Computer Science division and the Argonne Leadership Computing Facility. Finally, both align with and support Argonne’s Materials and Chemistry Initiative, whose mission is to reveal the undiscovered rules of hierarchical assembly that can lead to new functional solids, structured liquids and complex interfaces.

See the full article here .

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From Cornell Chronicle: “From Earth’s deep mantle, scientists discover a new way volcanoes form”

From Cornell Chronicle

May 15, 2019
Blaine Friedlander
bpf2@cornell.edu

Bermuda has a unique volcanic past. About 30 million years ago, a disturbance in the mantle’s transition zone supplied the magma to form the now-dormant volcanic foundation on which the island sits. Wendy Kenigsberg/Clive Howard – Cornell University, modified from Mazza et al. (2019)

Far below Bermuda’s pink sand beaches and turquoise tides, Cornell geoscientists have discovered the first direct evidence that material from deep within Earth’s mantle transition zone – a layer rich in water, crystals and melted rock – can percolate to the surface to form volcanoes.

In a cross-polarized microscopic slice of a core sample, the blue and yellow crystal is titanium-augite, surrounded by a ground mass of minerals, which include feldspars, phlogopite, spinel, perovskite and apatite. This assemblage suggests that the mantle source – rich in water – produced this lava. Gazel Lab/Provided

Scientists have long known that volcanoes form when tectonic plates (traveling on top of the Earth’s mantle) converge, or as the result of mantle plumes that rise from the core-mantle boundary to make hotspots at Earth’s crust.

The tectonic plates of the world were mapped in 1996, USGS.

But obtaining evidence that material emanating from the mantle’s transition zone – between 250 to 400 miles beneath our planet’s crust – can cause volcanoes to form is new to geologists.

“We found a new way to make volcanoes. This is the first time we found a clear indication from the transition zone deep in the Earth’s mantle that volcanoes can form this way,” said senior author Esteban Gazel, Cornell associate professor in the Department of Earth and Atmospheric Sciences. The research published in Nature on May 15.

“We were expecting our data to show the volcano was a mantle plume formation – an upwelling from the deeper mantle – just like it is in Hawaii,” Gazel said. But 30 million years ago, a disturbance in the transition zone caused an upwelling of magma material to rise to the surface, form a now-dormant volcano under the Atlantic Ocean and then form Bermuda.

Using a 2,600-foot core sample – drilled in 1972, housed at Dalhousie University, Nova Scotia – co-author Sarah Mazza of the University of Münster, Germany, assessed the cross-section for signature isotopes, trace elements, evidence of water content and other volatile material. The assessment provided a geologic, volcanic history of Bermuda.

“I first suspected that Bermuda’s volcanic past was special as I sampled the core and noticed the diverse textures and mineralogy preserved in the different lava flows,” Mazza said. “We quickly confirmed extreme enrichments in trace element compositions. It was exciting going over our first results … the mysteries of Bermuda started to unfold.”

From the core samples, the group detected geochemical signatures from the transition zone, which included larger amounts of water encased in the crystals than were found in subduction zones. Water in subduction zones recycles back to Earth’s surface. There is enough water in the transition zone to form at least three oceans, according to Gazel, but it is the water that helps rock to melt in the transition zone.

The geoscientists developed numerical models with Robert Moucha, associate professor of Earth sciences at Syracuse University, to discover a disturbance in the transition zone that likely forced material from this deep mantle layer to melt and percolate to the surface.

Despite more than 50 years of isotopic measurements in oceanic lavas, the peculiar and extreme isotopes measured in the Bermuda lava core had not been observed before. Yet, these extreme isotopic compositions allowed the scientists to identify the unique source of the lava.

“If we start to look more carefully, I believe we’re going to find these geochemical signatures in more places,” said co-author Michael Bizimis, associate professor at the University of South Carolina.

Gazel explained that this research provides a new connection between the transition zone layer and volcanoes on the surface of Earth. “With this work we can demonstrate that the Earth’s transition zone is an extreme chemical reservoir,” he said. “We are now just now beginning to recognize its importance in terms of global geodynamics and even volcanism.”

Said Gazel: “Our next step is to examine more locations to determine the difference between geological processes that can result in intraplate volcanoes and determine the role of the mantle’s transition zone in the evolution of our planet.”

Gazel is a fellow at Cornell’s Atkinson Center for a Sustainable Future and a fellow at Cornell’s Carl Sagan Institute. In addition to Gazel, Mazza, Bizimis and Moucha, co-authors of “Sampling the Volatile-Rich Transition Zone Beneath Bermuda,” are Paul Béguelin, University of South Carolina; Elizabeth A. Johnson, James Madison University; Ryan J. McAleer, United States Geological Survey; and Alexander V. Sobolev, the Russian Academy of Sciences.

The National Science Foundation provided funding for this research.

See the full article here .

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Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell University via Science Alert: “Gravitational Waves Could Be Leaving Some Weird Lasting Effects in Their Wake”

From Cornell University

via

Science Alert

8 MAY 2019
MICHELLE STARR

(Henze/NASA)

The faint, flickering distortions of space-time we call gravitational waves are tricky to detect, and we’ve only managed to do so in recent years. But now scientists have calculated that these waves may leave more persistent traces of their passing – traces we may also be able to detect.

Such traces are called ‘persistent gravitational wave observables’, and in a new paper [Physical Review D], an international team of researchers [see paper for science team authors] has refined the mathematical framework for defining them. In the process, they give three examples of what these observables could be.

Here’s the quick lowdown on gravitational waves: When two massive objects such as neutron stars or black holes collide, they send shockwaves through the Universe, rippling the very fabric of space-time itself. This effect was predicted by Einstein in his theory of general relativity in 1916, but it wasn’t until 2015 that we finally had equipment sensitive enough to detect the ripples.

That equipment is an interferometer that shoots two or more laser beams down arms that are several kilometres in length. The wavelengths of these laser beams interfere to cancel each other out, so, normally, no light hits the instrument’s photodetectors.

VIRGO Gravitational Wave interferometer, near Pisa, Italy

Caltech/MIT Advanced aLigo Hanford, WA, USA installation

Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project

Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger

Gravity is talking. Lisa will listen. Dialogos of Eide

ESA/eLISA the future of gravitational wave research

Localizations of gravitational-wave signals detected by LIGO in 2015 (GW150914, LVT151012, GW151226, GW170104), more recently, by the LIGO-Virgo network (GW170814, GW170817). After Virgo came online in August 2018

Skymap showing how adding Virgo to LIGO helps in reducing the size of the source-likely region in the sky. (Credit: Giuseppe Greco (Virgo Urbino group)

But when a gravitational wave hits, the warping of space-time causes these laser beams to oscillate, shrinking and stretching. This means that their interference pattern is disrupted, and they no longer cancel each other out – so the laser hits the photodetector. The pattern of the light that hits can tell scientists about the event that created the wave.

But that shrinking and stretching and warping of space-time, according to astrophysicist Éanna Flanagan of Cornell University and colleagues, could be having a much longer-lasting effect.

As the ripples in space-time propagate, they can change the velocity, acceleration, trajectories and relative positions of objects and particles in their way – and these features don’t immediately return to normal afterwards, making them potentially observable.

Particles, for instance, disturbed by a burst of gravitational waves, could show changes. In their new framework, the research team mathematically detailed changes that could occur in the rotation rate of a spinning particle, as well as its acceleration and velocity.

Another of these persistent gravitational wave observables involves a similar effect to time dilation, whereby a strong gravitational field slows time.

Because gravitational waves warp both space and time, two extremely precise and synchronised clocks in different locations, such as atomic clocks, could be affected by gravitational waves, showing different times after the waves have passed.

Finally, the gravitational waves could actually permanently shift the relative positions in the mirrors of a gravitational wave interferometer – not by much, but enough to be detectable.

Between its first detection in 2015 and last year, the LIGO-Virgo gravitational wave collaboration detected a handful of events before LIGO was taken offline for upgrades.

At the moment, there are not enough detections in the bank for a meaningful statistical database to test these observables.

But LIGO-Virgo was switched back on on 1 April, and since then has been detecting at least one gravitational wave event per week.

The field of gravitational wave astronomy is heating up, space scientists are itching to test new mathematical calculations and frameworks, and it won’t be long before we’re positively swimming in data.

This is just such an incredibly exciting time for space science, it really is.

See the full article here .

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Please help promote STEM in your local schools.

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Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell University: “Study: Nearest exoplanets could host life”

From Cornell University

04/08/2019
Linda B. Glaser

Excitement about exoplanets skyrocketed when rocky Earth-like planets were discovered orbiting in the habitable zone of some of our closest stars – until hopes for life were dashed by the high levels of radiation bombarding those worlds.

Proxima-b, only 4.24 light years away, receives 250 times more X-ray radiation than Earth and could experience deadly levels of ultraviolet radiation on its surface.

Proxima Centauri b (also called Proxima b or Alpha Centauri Cb)

How could life survive such a bombardment? Cornell astronomers say that life already has survived this kind of fierce radiation, and they have proof: you.

The intense radiation environments around nearby M stars could favor habitable worlds resembling younger versions of Earth.

Lisa Kaltenegger and Jack O’Malley-James make their case in a new paper, Lessons From Early Earth: UV Surface Radiation Should Not Limit the Habitability of Active M Star Systems, published April 9 in Monthly Notices of the Royal Astronomical Society. Kaltenegger is associate professor of astronomy in the College of Arts and Sciences and director of Cornell’s Carl Sagan Institute, at which O’Malley-James is a research associate.

All life on Earth today evolved from creatures that thrived during an even greater UV radiation assault than Proxima-b and other nearby exoplanets currently endure. The Earth of 4 billion years ago was a chaotic, irradiated, hot mess. Yet in spite of this, life somehow gained a toehold and then expanded.

The same thing could be happening at this very moment on some of the nearest exoplanets, according to Kaltenegger and O’Malley-James. The researchers modeled the surface UV environments of the four exoplanets closest to Earth that are potentially habitable: Proxima-b, TRAPPIST-1e, Ross-128b and LHS-1140b.

A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

Ross-128b

LHS 1140b – A Habitable Super-Earth 39 Light Years Away?

These planets orbit small red dwarf stars which, unlike our sun, flare frequently, bathing their planets in high-energy UV radiation. While it is unknown exactly what conditions prevail upon the surface of the planets orbiting these flaring stars, it is known that such flares are biologically damaging and can cause erosion in planetary atmospheres. High levels of radiation cause biological molecules like nucleic acids to mutate or even shut down.

O’Malley-James and Kaltenegger modeled various atmospheric compositions, from ones similar to present-day Earth to “eroded” and “anoxic” atmospheres – those with very thin atmospheres that don’t block UV radiation well and those without the protection of ozone, respectively. The models show that as atmospheres thin and ozone levels decrease, more high-energy UV radiation reaches the ground. The researchers compared the models to Earth’s history, from nearly 4 billion years ago to today.

Although the modeled planets receive higher UV radiation than that emitted by our own sun today, this is significantly lower than what Earth received 3.9 billion years ago.

“Given that the early Earth was inhabited,” the researchers wrote, “we show that UV radiation should not be a limiting factor for the habitability of planets orbiting M stars. Our closest neighboring worlds remain intriguing targets for the search for life beyond our solar system.”

An opposite question arises for planets orbiting inactive M stars on which the radiation flux is particularly low: Does the evolution of life require the high levels of radiation of early Earth?

To judge the potential habitability of worlds with varying rates of radiation influx, the researchers assessed the mortality rates at different UV wavelengths of the extremophile Deinococcus radiodurans, one of the most radiation-resistant organisms known.

Not all wavelengths of UV radiation are equally damaging to biological molecules: For example, write the researchers, “a dosage of UV radiation at 360 [nanometers] would need to be three orders of magnitude higher than a dosage of radiation at 260 [nanometers] to produce similar mortality rates in a population of this organism.”

Many organisms on Earth employ survival strategies – including protective pigments, biofluorescence, and living under soil, water or rock – to cope with high levels of radiation that could be imitated by life on other worlds, the researchers note. Subsurface life would be more difficult to find on distant planets without the kind of atmospheric biosignatures telescopes can detect.

“The history of life on Earth provides us with a wealth of information about how biology can overcome the challenges of environments we would think of as hostile,” O’Malley-James said.

Said Kaltenegger: “Our research demonstrates that in the quest for life on other worlds, our closest worlds are fascinating targets to explore.”

The researchers received funding from the Simon Foundation.

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Carl Sagan Institute via Science Alert: “Astronomers Have Found Potential Life-Supporting Conditions on The Nearest Exoplanet”

From Carl Sagan Institute

via

Science Alert

16 APR 2019
MATT WILLIAMS

Artist impression of an exoplanet from its moon. (IAU/L. Calçada)

In August of 2016, astronomers from the European Southern Observatory (ESO) announced the discovery of an exoplanet in the neighboring system of Proxima Centauri. The news was greeted with considerable excitement, as this was the closest rocky planet to our Solar System that also orbited within its star’s habitable zone.

Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

Since then, multiple studies have been conducted to determine if this planet could actually support life.

Unfortunately, most of the research so far has indicated that the likelihood of habitability are not good. Between Proxima Centauri’s variability and the planet being tidally-locked with its star, life would have a hard time surviving there.

However, using lifeforms from early Earth as an example, a new study [MNRAS] conducted by researchers from the Carl Sagan Institute (CSI) has shows how life could have a fighting chance on Proxima b after all.

Artist’s impression of Proxima b’s surface, orbiting the red dwarf star. (ESO)

The study, which recently appeared in the Monthly Notices of the Royal Astronomical Society [link is above], was conducted by Jack O’Malley-James and Lisa Kaltenegger – an research associate and the director of the Carl Sagan Institute at Cornell University.

Together, they examined the levels of surface UV flux that planets orbiting M-type (red dwarf) stars would experience and compared that to conditions on primordial Earth.

The potential habitability of red dwarf systems is something scientists have been debated for decades. On the one hand, they have a number of attributes that are encouraging, not the least of which is their commonality.

Essentially, red dwarfs are the most common type of star in the Universe, accounting for 85 percent of the stars in the Milky Way alone.

They also have the greatest longevity, with lifespans that can last into the trillions of years. Last, but not least, they appear to be the most likely stars to host systems of rocky planets.

This is attested to by the sheer number of rocky planets discovered around neighboring red dwarf stars in recent years – such as Proxima b, Ross 128b, LHS 1140b, Gliese 667Cc, GJ 536, the seven rocky planets orbiting TRAPPIST-1.

A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile

ESO Belgian robotic Trappist-South National Telescope at Cerro La Silla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.

However, red dwarf stars also present a lot of impediments to habitability, not the least of which is their variable and unstable nature. As O’Malley-James explained to Universe Today via email:

“The chief barrier to the habitability of these worlds is the activity of their host stars. Regular stellar flares can bathe these planets in high levels of biologically harmful radiation. Furthermore, over longer periods of time, the onslaught of X-ray radiation and charged particle fluxes from the host stars places the atmospheres of these planets at risk of being stripped away over time if a planet cannot replenish its atmosphere fast enough.”

For generations, scientists have struggled with questions regarding the habitability of planets that orbit red dwarf stars.

Unlike our Sun, these low-mass, ultra-cool dwarf stars are variable, unstable and prone to flare-ups. These flares release a lot of high-energy UV radiation, which is harmful to life as we know it and capable of stripping a planet’s atmospheres away.

This places significant limitations on the ability of any planet orbiting a red dwarf star to give rise to life or remain habitable for long. However, as previous studies have shown, much of this depends on the density and composition of the planets’ atmospheres, not to mention whether or not the planet has a magnetic field.

To determine if life could endure under these conditions, O’Malley-James and Kaltenegger considered what conditions were like on planet Earth roughly 4 billion years ago.

At that time, Earth’s surface was hostile to life as we know it today. In addition to volcanic activity and a toxic atmosphere, the landscape was bombarded by UV radiation in a way that is similar to what planets that orbit M-type stars experience today.

To address this, Kaltenegger and O’Malley-James modeled the surface UV environments of four nearby “potentially habitable” exoplanets – Proxima-b, TRAPPIST-1e, Ross-128b and LHS-1140b – with various atmospheric compositions. These ranged from ones similar to present-day Earth to those with “eroded” or “anoxic” atmospheres – i.e. those that don’t block UV radiation well and don’t have a protective ozone layer.

These models showed that as atmospheres become thinner and ozone levels decrease, more high-energy UV radiation is able to reach the ground. But when they compared the models to what was present on Earth, roughly 4 billion years ago, the results proved interesting. As O’Malley-James said:

“The unsurprising result was that the levels of surface UV radiation were higher than we experience on Earth today. However, the interesting result was that the UV levels, even for the planets around the most active stars, were all lower than the Earth experienced in its youth. We know the young Earth supported life, so the case for life on planets in M star systems may not be quite so dire after all.”

What this means, in essence, is that life could exist on neighboring planets like Proxima b right now despite being subjected to harsh levels of radiation. If you consider the age of Proxima Centauri – 4.853 billion years, which is roughly 200 million years older than our Sun – the case for potential habitability may become even more intriguing.

The current scientific consensus is that the first lifeforms on Earth emerged a billion years after the planet formed (3.5 billion years ago). Assuming Proxima b formed from a protoplanetary debris disk shortly after Proxima Centauri was born, life would have had enough time to not only emerge, but get a significant foothold.

While that life may consist solely of single-celled organisms, it is encouraging nonetheless. Aside from letting us know that there could very well be life beyond our Solar System, and on nearby planets, it provides scientists with constraints on what type of biosignatures may be discernible when studying them. As O’Malley-James concluded:

“The results from this study builds the case for focusing on life on Earth a few billion years ago; a world of single-celled microbes – prokaryotes – that lived with high UV radiation levels. This ancient biosphere may have the best overlaps with conditions on habitable planets around active M stars, so could provide us with the best clues in our search for life in these star systems.”

As always, the search for life in the cosmos begins with the study of Earth, since it is the only example we have of a habitable planet. It is therefore important to understand how (i.e. under what conditions) life was able to survive, thrive and respond to environmental changes throughout Earth’s geological history.

For while we may know of only one planet that supports life, that life has been remarkably diverse and has changed drastically over time.

Be sure to check out this video about these latest findings, courtesy of the CSI and Cornell University:

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Carl Sagan Institute (CSI) was founded to find life in the universe. Based on the pioneering work of Carl Sagan at Cornell, our interdisciplinary team is developing the forensic toolkit to find life in the universe, inside the Solar System and outside of it, on planets and moons orbiting other stars.

Recent scientific results show that in our galaxy alone there are billions of planets orbiting other suns. After billions of years of evolution on our own Pale Blue Dot and thousands of years of questioning, we finally have the technology in hand to explore other worlds inside and outside of our solar system. The information generated by the search for signs of life on other worlds also helps us understand and safeguard our own planet — our Pale Blue Dot — better.

CSI for the search of life in the universe: CSI explores factors that determine if a planet or moon can host life and how we could find it by bringing together experts from a wide range of disciplines, from sciences, engineering to media who work together with some of the planet’s most talented students at the undergraduate, graduate and postdoctoral level. CSI researchers use the latest data from space telescopes, probes to the solar system’s diverse worlds, field and satellite data on our home planet, laboratory studies of terrestrial organisms, and modeling of complex processes from the astronomical to the biological to explore these profound questions. And CSI researchers participate in the development of the next generation of space- and Earth-based facilities to probe ever deeper and farther.

CSI also interprets these results for the widest possible audience, sharing the fascination of science with everyone who is interested in where humankind stands in the quest to understand our place in the cosmos.

HISTORY

The Carl Sagan Institute was founded in 2015 at Cornell University to find life in the universe and explore other worlds – how they form, evolve and if they could harbor life both inside and outside of our own Solar System. Directed by astronomer Lisa Kaltenegger, the Institute has built an entirely new research group, spanning 14 departments at Cornell and including more than 25 faculty who focus on a wide range of the search for life in the universe interdisciplinarily.

The research group is embedded in a rich environment of established international interdisciplinary cooperation at Cornell. The Institute’s collaboration brings together researchers from fields as far apart as astrophysics, engineering, earth and atmospheric science, geology and biology to tackle questions as diverse as those about the astronomical context of the emergence of life on Earth, how to find it and what this discovery would mean for humankind.

From Cornell Chronicle: “Merged satellite, ground data may forecast volcanic eruptions”

From Cornell Chronicle

Kevin Reath, a Cornell University postdoctorate associate and USGS Powell Center Fellow, studied 17 years of satellite data on volcanic activity in Latin America to propose a way to predict deadly eruptions before they occur. John Munson/Cornell University

March 28, 2019
Blaine Friedlander
bpf2@cornell.edu

On Nov. 13, 1985, the Nevado del Ruiz volcano in the Andes – about 80 miles west of Bogota, Colombia – erupted, sending a pyroclastic flow down its mountainside.

The heat melted the snow at an elevation of more than 17,000 feet, and volcanic ash muddied the resulting water – called lahar – that rushed into the nearby town of Amero. More than 23,000 people died.

Guatemala’s cone-shaped, very active Fuego volcano spews an ash column. It last erupted in June 2018. Kevin Reath/Cornell University

“This volcano killed over 70 percent of the town’s population. They were unprepared for the eruption,” said Kevin Reath, a Cornell postdoctoral researcher.

Reath’s work aims to prevent that from happening again. He has merged 17 years of satellite data on volcanoes with ground-based detail to form a model for state-of-the-art volcanic eruption prediction.

Reath’s paper, “Thermal, Deformation, and Degassing Remote Sensing Time Series (CE 2000–2017) at the 47 Most-Active Volcanoes in Latin America: Implications for Volcanic Systems,” was published in the Journal of Geophysical Research: Solid Earth (American Geophysical Union) in February.

“Volcanoes are hazardous to local and global populations, but only a fraction of volcanoes are continuously monitored by ground‐based sensors,” Reath said.

In South America, volcanoes lace the Ring of Fire around the Pacific Ocean. More than 60 percent of Holocene-era volcanoes in Latin America are unmonitored by ground-based sensors, and those with ground sensors still have gaps that satellites can fill, Reath said.

“We are compiling remote sensing data that has been underutilized,” he said.

The model aggregates three types of critical information: thermal data, such as volcanic hot spots and how they change over time; degassing data, which examines the presence of sulfur dioxide; and deformation data, accounting for inflation and deflation of magma reservoirs – pockets of lava inside the Earth.

“These data types have never really been intercompared in such an extensive database,” said Reath, who hopes to extract a more-robust understanding of volcanic processes.

But his work is not all volcanic eruptions. With over 17 years of satellite data, the scientists can find value in observing quiet among the volcanoes. “When we can see the volcano calm and then see the volcano when it is erupting, we can observe what’s happening leading to eruption. We can get a comprehensive picture of a volcanic behavior,” he said.

“Volcanoes have personalities,” Reath said. “Sometimes they have multiple personalities. Volcanoes can behave differently from each other, and volcanic behavior – from the same volcano – can vary from eruption to eruption. It helps geologists to understand what to look for before an eruption. We’re looking for typical volcanic background behavior and pre-eruptive behavior.”

Joining Reath on the paper are: Matthew Pritchard, Cornell professor, earth and atmospheric sciences; Francisco Delgado, Ph.D. ’18; Samantha Moruzzi ’20 and Allison Alcott ’18; and Scott Henderson, Ph.D. ’15, former Cornell postdoctoral researcher. This work was supported by NASA; the European Space Agency; and the Volcano Remote Sensing Working Group, John Wesley Powell Center for Analysis and Synthesis, U.S. Geological Survey.

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Cornell Chronicle: “Saturn’s icy rings reveal another secret: they’re young”

From Cornell Chronicle

January 23, 2019
Blaine Friedlander

Cassini’s wide-angle camera captures the sunlit side of Saturn’s rings June 26, 2016, offering a good view of the B ring from about 940,000 miles away.
NASA/JPL-Caltech/Space Science Institute

Data from the last days of the NASA spacecraft Cassini show that Saturn’s beautiful, extensive rings are relatively young – perhaps created when dinosaurs roamed the Earth – because the ring’s mass is less than previously thought and its frozen components are surprisingly bright and free from dusty cosmic impurities, according to a study published Jan. 17 in Science.

“Based on previous research, we suspected the rings were young, but not everyone was convinced,” said Phil Nicholson, Cornell professor of astronomy and a co-author of “Measurement and Implications of Saturn’s Gravity Field and Ring Mass”[Science above].

Before Cassini’s demise when it crashed into Saturn in September 2017, the spacecraft passed repeatedly between the rings and the planet’s cloud tops to study Saturn’s gravity field and the rings’ mass.

NASA/ESA/ASI Cassini-Huygens Spacecraft

Cassini (and two Voyager spacecraft) had studied Saturn’s rings from afar, but no craft had yet ventured into the rings to obtain up-close data.

NASA/Voyager 1

NASA/Voyager 2

Before its final planetary plunge, Cassini dove through the rings 22 times, using six passes to measure the gravity field by tracking the radio signal from the spacecraft. (The technique is similar to a police radar, but more precise; Cassini’s velocity was measured with an accuracy of better than 0.1 millimeter per second.)

The scientists found that the rings – particularly the dense B-ring, one of the three main rings and the brightest visible in a telescope – had lower masses than many had expected, indicating a relatively young age. While Saturn is about 4.5 billion years old, the new Cassini data indicate that the rings probably formed between 10 million and 100 million years ago, according to the lead researchers from Sapienza University in Rome.

Had the rings been contaminated and darkened by interplanetary debris over a longer period, they would appear much darker, according to NASA’s Jet Propulsion Laboratory.

“The new mass measurement is firm, because Cassini was able to pass inside the rings. In our prior research, we used waves driven in the rings by Saturn’s moons to indirectly estimate their mass density at several locations, which we then extrapolated to estimate the total mass of the rings,” said Nicholson, who had conducted that earlier research at Cornell with Matt Hedman, now an assistant professor of astronomy at the University of Idaho. “Our final result was very close to the new measurement, but lower than most earlier estimates.”

“From what we know based on Cassini’s spectral and radar measurements, the rings are also less contaminated than previously thought – probably less than 1 percent,” said Nicholson. “They are close to pure water ice.”

In 2016, Zhimeng Zhang, Ph.D. ’16, led work examining the dust content of Saturn’s C ring. This research determined that the C ring, once thought to have formed in the primordial era, was less than 100 million years old. In 2017, she reported on similar measurements of the A and B rings, obtaining similarly young ages.

“Think of an unused desk in an unused room. The more it sits there, the more it collects dust,” Zhang said when she published her work. “The C ring is the same way. While it is composed mostly of water ice, it collects silicate-containing dust from the far-off Kuiper Belt. … [I]n this case, the dust – in terms of the age of the solar system – has not been here a long time.”

Among ring scientists, Nicholson and others had wagered what Cassini might find in terms of ring mass. The result was close to Nicholson’s prediction. He said: “This is quite gratifying from a scientific and personal point-of-view that we got close to the real number when Cassini finally measured it.”

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

From Brookhaven National Lab: “Brookhaven Delivers Innovative Magnets for New Energy-Recovery Accelerator”

From Brookhaven National Lab

January 2, 2019
Karen McNulty Walsh
kmcnulty@bnl.gov

Test accelerator under construction at Cornell will reuse energy, running beams through multi-pass magnets that help keep size and costs down.

Members of the Brookhaven National Laboratory team with the completed magnet assemblies for the CBETA project.

When it comes to particle accelerators, magnets are one key to success. Powerful magnetic fields keep particle beams “on track” as they’re ramped up to higher energy, crashed into collisions for physics experiments, or delivered to patients to zap tumors. Innovative magnets have the potential to improve all these applications.

That’s one aim of the Cornell-Brookhaven “Energy-Recovery Linac” Test Accelerator, or CBETA, under construction at Cornell University and funded by the New York State Energy Research and Development Authority (NYSERDA). CBETA relies on a beamline made of cutting-edge magnets designed by physicists at the U.S. Department of Energy’s Brookhaven National Laboratory that can carry four beams at very different energies at the same time.

Cornell BNL ERL test accelerator

“Scientists and engineers in Brookhaven’s Collider-Accelerator Department (C-AD) just completed the production and assembly of 216 exceptional quality fixed-field, alternating gradient, permanent magnets for this project—an important milestone,” said C-AD Chair Thomas Roser, who oversees the Lab’s contributions to CBETA.

The novel magnet design, developed by Brookhaven physicist Stephen Brooks and C-AD engineer George Mahler, has a fixed magnetic field that varies in strength at different points within each circular magnet’s aperture. “Instead of having to ramp up the magnetic field to accommodate beams of different energies, beams with different energies simply find their own ‘sweet spot’ within the aperture,” said Brooks. The result: Beams at four different energies can pass through a single beamline simultaneously.

In CBETA, a chain of these magnets strung together like beads on a necklace will form what’s called a return loop that repeatedly delivers bunches of electrons to a linear accelerator (linac). Four trips through the superconducting radiofrequency cavities of the linac will ramp up the electrons’ energy, and another four will ramp them down so the energy stored in the beam can be recovered and reused for the next round of acceleration.

“The bunches at different energies are all together in the return loop, with alternating magnetic fields keeping them oscillating along their individual paths, but then they merge and enter the linac sequentially,” explained C-AD chief mechanical engineer Joseph Tuozzolo. “As one bunch goes through and gets accelerated, another bunch gets decelerated and the energy recovered from the deceleration can accelerate the next bunch.”

Even when the beams are used for experiments, the energy recovery is expected to be close to 99.9 percent, making this “superconducting energy recovery linac (ERL)” a potential game changer in terms of efficiency. New bunches of near-light-speed electrons are brought up to the maximum energy every microsecond, so fresh beams are always available for experiments.

That’s one of the big advantages of using permanent magnets. Electromagnets, which require electricity to change the strength of the magnetic field, would never be able to ramp up fast enough, he explained. Using permanent fixed field magnets that require no electricity—like the magnets that stick to your refrigerator, only much stronger—avoids that problem and reduces the energy/cost required to run the accelerator.

To prepare the magnets for CBETA, the Brookhaven team started with high-quality permanent magnet assemblies produced by KYMA, a magnet manufacturing company, based on the design developed by Brooks and Mahler. C-AD’s Tuozzolo organized and led the procurement effort with KYMA and the acquisition of the other components for the return loop.

Engineers in Brookhaven’s Superconducting Magnet Division took precise measurements of each magnet’s field strength and used a magnetic field correction system developed and built by Brooks to fine-tune the fields to achieve the precision needed for CBETA. Mahler then led the assembly of the finished magnets onto girder plates that will hold them in perfect alignment in the finished accelerator, while C-AD engineer Robert Michnoff led the effort to build and test electronics for beam position monitors that will track particle paths through the beamline.

“Brookhaven’s CBETA team reached the goals of this milestone nine days earlier than scheduled thanks to the work of extremely dedicated people performing multiple magnetic measurements and magnet surveys over many long work days,” Roser said.

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

BNL NSLS-II

BNL NSLS II

BNL RHIC Campus

BNL/RHIC Star Detector

BNL RHIC PHENIX

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

From Cornell University via Science Alert: “A Genius Microscopy Method Just Set a Record in Imaging Individual Atoms”

From Cornell University

via

Science Alert

20 JUL 2018
MIKE MCRAE

Two overlaid sheets of molybdenum disulfide (Cornell University)

Electron microscopes have been capable of taking snapshots of individual atoms for nearly half a century. But we’ve never seen anything quite on this scale.

A new method for catching and measuring the spray of electron beams is giving us a whole new resolution of the sub-ångström world, opening the way to studying molecular structures that would be impossible to see using existing methods.

Last year, engineers at Cornell University in the US performed the equivalent of eye surgery on the traditional electron microscope, ditching the need for corrective lenses and improving the way the eye itself collects and measures light.

Now we have evidence of exactly what that technology can achieve, measuring the bonds between atoms with unprecedented clarity.

At a fundamental level, all microscopes work in a fairly similar way – an object is showered in waves of energy, which are collected and arranged in such a way that we can deduce its shape. Smaller waves mean smaller details.

Electrons can have pretty small wave-like properties that depend on the energy they contain, making them perfect for seeing extra small objects. Instead of lenses, they’re focussed using electromagnetic fields.

Aberrations in these fields can limit the size of objects we can see, much as deviations in lenses can blur images. Engineers usually fix these with the electron microscope equivalent of glasses, adding corrective devices to ‘fix’ the picture.

This fix only goes so far, though. Multiple aberrations demand additional devices, which could theoretically pile up to the point that it’s an engineering nightmare.

A device called an electron microscope pixel array detector (EMPAD) does away with the need for these ‘glasses’ by taking another approach. It’s a catcher’s mitt for electrons that bounce off the sample made up of a 128 x 128 array of electron-sensitive pixels.

Rather than build an image based on the location of the electrons, it detects the angles of each electron’s reflection.

Working backwards using a technique usually applied to X-ray microscopy called ptychography, it’s possible to build a four-dimensional map that tells not only where the electrons came from, but their momentum as well.

The team put the combination of EMPAD and ptychography to the test by analysing the structure of two stacked sheets of molybdenum disulfide, each a single atom thick.

By rotating one sheet a few degrees, they could compare distances in overlapping atoms, setting a record of resolving a distance of just 0.39 ångströms.

“It’s essentially the world’s smallest ruler,” says physicist Sol Gruner.

The lattice (pictured above) was so clear, they spotted a single missing sulphur atom.

But apart from bragging rights, the technique has another massive advantage.

Electron waves can be made smaller by pumping up their energy. More energy means shorter wavelengths. State-of-the-art microscopes can emit streams of electrons at 300 kiloelectronvolts that can resolve details just under 0.05 nanometres, or 0.5 ångströms.

But more energy can also turn those electrons from a gentle sprinkle of particles into a machine gun burst, putting molecules at risk of disintegrating.

Since this beam was a gentle 80 keV, the electrons weren’t energetic enough to break up the structure of the molybdenum disulfide sheets, as they might in a more traditional setup.

Lower energy electron beams mean we can now study bonds in delicate molecules like never before, giving electron microscopy a more gentle touch while providing a whole new level of detail.

This is some artwork we look forward to hanging on our wall.

This research was published in Nature.

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.