Thursday: Chat with physicists on Twitter

May 16, 2012 | 2:08 pm

Image courtesy of id-iom via a Creative Commons License.

Thursday at 1 p.m. EST, accelerator physicists from four national laboratories will take to Twitter to discuss discovery science with the tweeting public. To take part in the event, dubbed Lab Breakthrough Office Hours, use the hashtag #labchat.

The Office Hours tweetchat is part of the Lab Breakthrough video series, which highlights the technological feats accomplished in fundamental and applied research.

Meet the physicists

Fermi National Accelerator Laboratory’s associate director for accelerators, Stuart Henderson, will be tweeting from @FermilabToday. Henderson can answer questions about science at Fermilab, the subatomic workings of the universe or his 20 years of accelerator work at Oak Ridge National Laboratory, Cornell and Yale.

Thomas Jefferson National Accelerator Facility scientists Gianluigi Ciovati and Pashupati Dhakal will be tweeting from @JBLAB. Ciovati and Dhakal can answer questions about how accelerators work and how they are used. They also volunteer to explain absolutely anything about the element niobium.

An accelerator scientist at SLAC National Accelerator Laboratory, operated by Stanford University, will be tweeting from @SLACLab. This scientist will be able to answer questions about SLAC’s large instruments that examine the infinitesimal, including the Linac Coherent Light Source, which captures images at the atomic level with a “shutter speed” measured in trillionths of a second.

Can’t make it to the tweetchat? You can still submit questions beforehand to #labchat in a tweet or send them via email or Facebook to the Department of Energy.

Read Q&As with other Lab Breakthroughs researchers on the energy.gov topic page, or see the full video series on the Lab Breakthrough YouTube playlist.

Kathryn Grim

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Researchers developing underwater neutrino experiment make oceanographic discovery

May 15, 2012 | 4:45 pm

Artistic rendering of the NEMO submarine telescope. Image: INFN

Scientists working on an underwater neutrino observatory recently announced their second discovery, and they haven’t even installed their detectors.

Researchers deciding where to place the planned Neutrino Mediterranean Observatory, or NEMO, were measuring water currents and temperatures when they stumbled upon unexpected patterns in the water. They found chains of marine vortices — water structures approximately 6 miles in diameter rotating at about 1 inch per second — nearly 2 miles deep in the Ionian Sea, an arm of the Mediterranean.

Oceanographers did not expect vortices to form in a closed basin such as the Mediterranean. Their origins could be local, but the vortices also could have traveled hundreds of miles from the Adriatic or Aegean seas, according to simulations.

Five years ago, NEMO researchers made their first surprising discovery. During the course of their research, they found a variety of marine life, including sperm whales, living more than a mile beneath the surface offshore from Catania, Italy.

NEMO experiments will study high-energy neutrinos coming from deep space using thousands of detectors placed beneath the sea.

Kathryn Grim

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New accelerator to study steps on the path to fusion

May 9, 2012 | 9:30 am

A close view of modules in the NDCX-II induction linear accelerator. Image: Berkeley Lab

Berkeley Lab scientists and engineers announced in a press release on May 8 that they have completed a machine tailor-made to examine one approach to fusion power.

Scientists designed the particle accelerator, called the second-generation Neutralized Drift Compression Experiment, to make advances in the acceleration, compression and focusing of intense ion beams used in research into heavy-ion fusion. These beams can deliver a powerful punch to a thin target, heating the material quickly and evenly.

The eventual goal of heavy-ion fusion is to produce electrical power with particle accelerators through a process called inertial confinement fusion, in which the careful heating and compressing of a pellet of fuel sets off a nuclear fusion reaction.

Scientists and engineers from Berkeley, Lawrence Livermore National Laboratory and the Princeton Plasma Physics Laboratory worked together as part of the U.S. Department of Energy’s Heavy Ion Fusion Science Virtual National Laboratory to build the machine.

Kathryn Grim

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Fermilab scientists revise plans for construction of new accelerator project

May 7, 2012 | 4:16 pm

The proposed Project X would tie into the existing Fermilab accelerator complex. Image: Fermilab

Members of the team planning the accelerator project that will power Fermilab’s future experiments announced this week that they have developed ways to construct the project in three stages.

With their eyes on the tight federal budget, scientists plan to divide the endeavor, called Project X, into phases in order to lessen the initial costs. Last month, the U.S. Department of Energy asked Fermilab to look into ways to build the proposed Long Baseline Neutrino Experiment in stages for the same reason.

“As much as we’d like to have the full Project X at one time, we respect that funding cannot support that,” said Bob Tschirhart, project scientist for the research program. In total, Project X is estimated to cost between $1 billion and $2 billion.

Project X is a proposed proton accelerator complex that could throughout its stages provide beam for more than 20 experiments. These experiments would each take about 50 to 300 scientists to run — as opposed to experiments at particle colliders such as Fermilab’s now-closed Tevatron or the Large Hadron Collider, the collaborations for which can number in the thousands.

According to a study conducted by the laboratory, the full suite of Project X experiments could support 1,500 to 2,000 users from around the world, roughly the same number who worked on experiments at the Tevatron.

New particles, even those beyond the energy scale accessible at the Large Hadron Collider, can affect the ways other particles such as muons, kaons and the nuclei of atoms behave. Future Fermilab experiments powered by Project X would focus on sending high-intensity beams of particles through sensitive detectors to catch these effects in action. But scientists need to use multiple indirect searches to make a clear picture.

“It’s kind of like a game of Clue,” Tschirhart said. “If you observe a muon converting into an electron, it tells you the murder happened in the dining room. But you still don’t know what the weapon was. Each experiment helps us see the pattern.”

Kathryn Grim

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NOvA neutrino detector’s future home in Minnesota complete

May 3, 2012 | 1:29 pm

Officials from the U.S. Department of Energy, the University of Minnesota and Fermi National Accelerator Laboratory dedicate the NOvA Laboratory near the Ash River, Minn. Photo: Reidar Hahn

Fermilab Director Pier Oddone wrote the following column for Fermilab Today after attending the inauguration of the facility that will hold the NOvA neutrino experiment’s largest detector.

On April 27, more than 250 people gathered to inaugurate the NOvA facility near the Ash River in northern Minnesota. The facility consists of the huge far detector building, building fixtures and the impressive lifter that will position the NOvA blocks in their vertical position. When standing in the hall where the detector will be built, the building looks astonishingly large: It almost seems impossible that one day soon almost every square foot will be filled with detector.

The NOvA far detector, when complete, will be the largest plastic structure in the world. Sixteen-meter-long PVC tubes will form planes nearly 50 feet by 50 feet square. The planes will be stacked and glued 32 layers at a time and then pivoted to their final vertical position in the detector hall. Nearly 10,000 kilometers of wave-shifting fiber will be threaded through the 368,000 individual tubes, and finally the detector will be filled with 3,200,000 gallons of mineral oil loaded with scintillator.

More than 170 undergraduates are at work in the factory where individual modules are made before being shipped to the NOvA facility. They are manufacturing the detector planes and, in the process, learning all about running a large factory with the complex workflows and many quality assurance procedures required for successful production. Here at Fermilab, we have just begun upgrading our accelerator complex to produce the highest-power multi-GeV neutrino beam in the world starting in 2013.

The NOvA facility and our accelerator complex that creates the neutrino beam together constitute extraordinary means to carry out extraordinary science. The recent measurement by the Daya Bay reactor experiment in China, confirmed by the RENO reactor experiment in Korea, shows us that the door is wide open for the next set of measurements in the neutrino sector. NOvA will be the first with the ability to tell us how the masses of the neutrinos are arranged.

The completion of the NOvA facility required exceptional efforts on multiple fronts. The collaboration generated an excellent detector design and, after testing it using a prototype detector on our Fermilab site, is ready to start building it at full scale. The University of Minnesota has done a remarkable job in managing the construction of the facility and running the Ash River laboratory. The facility’s design firm and the construction company have also done a great job, and we continue to receive strong support from the Minnesota Department of Natural Resources. The DOE Fermi Site Office and the DOE Office of High Energy Physics have been extraordinarily helpful all the way along the process. And our legislators in congress have helped us overcome unusual turbulence along the road.

Building the extraordinary NOvA experiment has required extraordinary collaboration and determination. It has not been very long since the project’s funding was zeroed out by the FY 2008 omnibus funding bill and the NOvA team dispersed to other projects. Friday’s event shows that despite the nutty and unstable way in which we manage science in our country, we can still get big projects done.

- Fermilab Director Pier Oddone

Guest author

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May 2012 issue of symmetry available

May 1, 2012 | 3:07 pm

We’ve done it again. The May issue of symmetry is now available online.

In this issue, symmetry goes hunting for dark matter with BaBar, searching for light dark photons and dark Higgs bosons in data originally taken to explain a completely different mystery.

We take you into the world of physicist and famous conference-organizer Jean Tran Thanh Van, whose humanitarian efforts, combined with his vision of a cohesive international particle physics community, have led him around the world and back to his home country of Vietnam.

Symmetry also explores the High Temperature Material Laboratory at Oak Ridge National Laboratory, where engineers from John Deere and General Motors evaluate their products to improve durability and efficiency; visits Paris’ Trocadéro science exhibition, where science enthusiasts can see—and even control—a real electron accelerator; and introduces the Twinkie of particle physics.

To catch all future issues of symmetry, please subscribe to our email update list. We promise to only send you the good stuff.

Kelen Tuttle

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FACET test facility hosts first users

April 30, 2012 | 2:58 pm

SLAC graduate student Spencer Gessner aligns a mirror for FACET's x-ray spectrometer. The instrument was just one of the many new instruments and pieces of equipment installed to turn part of SLAC's 50-year-old linear accelerator into a new user facility. (Photo: Brad Plummer)

After months of installation and commissioning efforts, FACET, the Facility for Advanced Accelerator Experimental Tests, welcomed its first two groups of experimenters on Friday. They came to the facility, located at SLAC National Accelerator Laboratory, to use the tightly focused electron bunches for two very different purposes.

One group of collaborators from SLAC, the University of California–Los Angeles and the Max Planck Institute of Physics in Berlin will continue their efforts to make accelerators smaller and more efficient using a technique called plasma wakefield acceleration. This technique can accelerate electron or positron bunches to extremely high energies within a very short distance—much shorter than SLAC’s original two-mile-long linear accelerator.

According to Spencer Gessner, a graduate student at SLAC and a member of the team, “One of the goals of this first run is to replicate and then extend some of the results achieved by E167,” a plasma wakefield experiment that took place at SLAC’s Final Focus Test Beam before it shut down in 2007. E167 raised the energy of a few electrons from 42 billion to 85 billion electronvolts over a distance of just in 84 centimeters—a little less than a yard.

The team will have three more opportunities during this first user run to push the science further. “This summer we want to go from accelerating a few electrons to accelerating bunches of sufficient size and density to do science with,” said Mark Hogan, head of the plasma acceleration group in SLAC’s Advanced Accelerator Research Department.

In the second experiment, Ioan Tudosa of the Stanford Institute for Materials and Energy Science, a joint SLAC–Stanford institute, will also continue work previously done at SLAC, this time in magnetic switching. The magnetic switching technique, in which an electric field is used to make north and south poles swap places in a magnet, works more than 1000 times faster than current technology and could revolutionize data storage. Tudosa will expose magnetic samples to FACET’s powerful electron pulses.

John Seeman, interim FACET director, is happy that the user run is here. “After the intense commissioning run last summer, a busy maintenance period and then recommissioning in March and April, the FACET team is now ready to provide 20 GeV intense electron bunches to the accelerator user community for a broad array of cutting-edge accelerator experiments,” he said. “It is going to be an exciting run.”

Hogan has been working on plasma wakefield acceleration for over a decade. He says he’s as much thankful as happy to see FACET open to users. “I’m just grateful for the efforts of the linac operations staff and everyone at SLAC who have been working so hard to get FACET ready for the users to do science,” he said.

Lori Ann White

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CMS collaboration discovers its first new particle

April 27, 2012 | 4:48 am

The excited, neutral Xi_b baryon decays in a multi-step process with long-lived particles, making it complicated for scientists to trace back to the original particle. Image: CMS collaboration

Members of the CMS collaboration announced the experiment’s first discovery of a new particle today.

In a paper submitted to Physical Review Letters, the CMS collaboration described the first observation of an excited, neutral Xi_b baryon, a particle made up of three quarks, including one beauty quark.

The new baryon is one of many particles made up of quarks predicted by the theory of quantum chromodynamics.

“We have found a very large fraction of these particles,” said CMS physicist Vincenzo Chiochia, one of the co-leaders of the search. “But there are still very heavy ones and excited states to be discovered.”

Individual quarks cannot float around on their own; scientists find them bound in pairs or in groups of three. Theory describes the different ways in which quarks should connect. It also predicts the existence of excited states of particles made of quarks.

The first new particle discovered by the ATLAS collaboration, announced in December 2011, was an excited state of a particle made up of two quarks.

Until now, physicists had only ever seen Xi_b baryons in their ground states. The excited Xi_b baryon is the heaviest baryon to be discovered in the Xi baryon family.

A particle becomes excited when it has higher than its minimal amount of energy. Not long after excited particles form in particle collisions such as those in the Large Hadron Collider, they break down into ground-state particles by releasing energy in the form of smaller particles.

The excited Xi_b baryon breaks apart into long-lived particles that can travel half of a meter from the collision point before decaying. This gives physicists long lines to draw as they connect the dots to find the origin of the final products of the decay. They do all of this through the confusion of about 20 other particle collisions happening in the same instant.

“Finding this particle is really very hard,” Chiochia said. “Finding this complicated decay in such a messy event makes us confident in our abilities to find other new particles in the future.”

Kathryn Grim

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Citizen scientists find new purpose in pulsar search

April 26, 2012 | 1:39 pm

Bruce Allen, leader of the Einstein@Home project. Image courtesy N. Michalke / AEI Hannover

A project that lets citizen volunteers contribute to scientists’ search for gravitational waves, theoretical ripples in the fabric of space-time, has expanded its efforts — with impressive results.

The Einstein@Home project began in 2005 as a way for people to donate idle computing time to the Laser Interferometer Gravitational Wave Observatory. LIGO facilities in Washington and Louisiana watch for gravitational waves set off by collisions between neutron stars to subtly disrupt beams of light as they bounce between mirrors.

Albert Einstein predicted the existence of gravitational waves based on his theory of relativity in 1916. But Einstein@Home users and LIGO scientists have yet to spot any.

So in 2009, the Einstein@Home project began using volunteers’ computers to comb through data from additional sources: the Fermi Gamma-ray Space Telescope, the Arecibo Observatory and the Parkes Radio Telescope. They have yet to find gravitational waves, but they’ve become quite accomplished at finding young neutron stars, called pulsars.

“The chance of finding a new pulsar is one in 10 million,” said Bruce Allen, head of Einstein@Home, in an interview for the publication iSGTW. In less than two years, Einstein@Home users have already found 27.

These discoveries, in turn, may feed back into future research into gravitational waves. Some scientists think that they can use the pulsars themselves, which emit measurable X-rays as they spin, to conduct enormous-scale versions of the light-beam experiments at LIGO. The more pulsars Einstein@Home users help find, the more resources seekers of gravitational waves will have.

Read the iSGTW article.
Learn more about participating in Einstein@Home.

Kathryn Grim

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World’s largest digital camera one step closer to reality

April 24, 2012 | 10:08 am

A digital rendering of the LSST instrument, with human figures for scale. (Image courtesy LSST Corporation/NOAO)

Perched high atop Cerro Pachón in the Chilean Andes, the Large Synoptic Survey Telescope will take the largest, fastest, most detailed pictures of the Southern Hemisphere’s night sky. With these images, researchers around the world will seek to reveal the nature of dark matter and dark energy—and to answer a host of other questions in astronomy and physics.

To do all this, LSST needs the largest digital camera ever built: a 3.2 billion-pixel behemoth that stands 6 feet tall and weighs more than 6000 pounds. Now, this impressive instrument has taken a significant step toward reality by receiving the Department of Energy’s “Critical Decision 1” approval.

The DOE-led camera team, which is based at SLAC National Accelerator Laboratory, will now begin a detailed engineering design, schedule and budget phase. Construction on the telescope is expected to begin in 2014, with first light five years after that.

Learn more about the CD-1 announcement in SLAC’s press release, and more about the telescope itself in “The LSST’s supersized sweep of the sky,” published in the February 2011 issue of symmetry.

Kelen Tuttle

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