Friday, November 17, 2017

Earthbound antimatter mystery deepens after scientists rule out pulsar source

HAWC sees the pulsars Geminga and PSR B0656+14 as broad beacons of gamma rays, HAWC image.

Particles like positrons that carry an electric charge are difficult to detect on Earth since they can be deflected by the planet's magnetic field. But scientists have a workaround. The particles also interact with the cosmic microwave background — an ever-present stream of low-energy photons left over from the birth of the universe. "The high-energy electron, or positron, [will] kick the low-energy photon ... so this the photon becomes a high-energy gamma-ray," Zhou said. "These gamma-rays, which have no electric charge, can pass right through the magnetic field and make it all the way to Earth's surface. (Full Story)

Also from Science News

Stellar explosion rocks the universe

Merger of two equal mass neutron stars is simulated using a 3-D computer code, LANL image.

Astrophysicists at Los Alamos National Laboratory were enjoying a typical Friday evening with friends and family on Aug. 25, 2017, when they began hearing excited chatter about a major new astronomical observation pouring in over the phone and social media.

Breaking news doesn’t happen that often in astronomy, and this was big. LIGO, the Laser Interferometer Gravitational-wave Observatory, had detected another gravitational-wave signal, just the fifth announced by the LIGO team since the observatory began operating two years ago. (Full Story)

Scalable clusters make HPC R&D easy as raspberry pi

Gary Grider at the SC17 news conference, LANL photo.

A quest to help the systems software community work on very large supercomputers without having to actually test on them has spawned an affordable, scalable system using thousands of inexpensive Raspberry Pi nodes. It brings a powerful high-performance-computing testbed to system-software developers, researchers, and others who lack machine time on the world’s fastest supercomputers.

“It’s not like you can keep a petascale machine around for R&D work in scalable systems software,” said Gary Grider, leader of the High Performance Computing Division at Los Alamos National Laboratory, home of the Trinity supercomputer. “The Raspberry Pi modules let developers figure out how to write this software and get it to work reliably without having a dedicated testbed of the same size, which would cost a quarter billion dollars and use 25 megawatts of electricity.” (Full Story)

Also from The Register

NASA's space nuclear reactor could be the key to colonising Mars

NASA illustration of a Kilopower spacecraft.

"A space nuclear reactor could provide a high energy density power source with the ability to operate independent of solar energy or orientation, and the ability to operate in extremely harsh environments, such as the Martian surface," Patrick McClure, project lead on the Kilopower work at the Los Alamos National Laboratory, said in a statement.

David Poston, the reactor's chief designer said that the technology could also be used in NASA's other space exploration missions. However, the pioneering project will require that scientists keep it simple. (Full Story)

First observations of how a meteor-like shock turns silica into glass

The process that turns silica into shocked glass, LANL image.

The experiments took place at SLAC’s Linac Coherent Light Source (LCLS) X-ray laser, a DOE Office of Science User Facility whose ultrafast pulses can reveal processes taking place in millionths of a billionth of a second with atomic resolution.

“We were able for the first time to really visualize from start to finish what happens in a material that makes up a major portion of the Earth’s crust,” said Arianna Gleason of the DOE’s Los Alamos National Laboratory, the principal investigator for the study, which was published Nov. 14 in Nature Communications. (Full Story)

X-rays reveal the anatomy of an explosion

Scientists have used X-rays to study how an explosion rips through material in a confined space.

Explosives release energy as they burn, but exactly how the energy is released when the explosive material is enclosed is not well understood. Laura Smilowitz and her colleagues at the Los Alamos National Laboratory in New Mexico used X-rays to peer into aluminium canisters packed with an explosive and heated to ignition. The team recorded high-resolution X-ray movies showing how the burning explosives morphed from solid to gas. (Full Story)

Researchers take next step toward fusion energy

Experimental apparatus, from Texas A&M.

The sun makes energy by fusing hydrogen atoms, each with one proton, into helium atoms, which contain two protons. Helium is the byproduct of this reaction. Although it does not threaten the environment, it wreaks havoc upon the materials needed to make a fusion reactor.

Working with a team of researchers at Los Alamos National Laboratory in New Mexico, Michael Demkowicz of Texas A&M University investigated how helium behaves in nanocomposite solids, materials made of stacks of thick metal layers. (Full Story)

SLAC knows how the universe works

Newer parts of SLAC are built of gleaming metal. C-Net photo.

A $1 billion upgrade at the Stanford Linear Accelerator Center called LCLS-II is turning the 2-mile-long accelerator into the world's most powerful X-ray laser. X-rays this powerful can be used like a super-intense camera flash

Often, repurposing is significantly more cost-effective than building from scratch," said John Sarrao, an associate director at Los Alamos National Laboratory in New Mexico, another Energy Department-funded facility that has its own linear accelerator. (Full Story)

LANL Foundation brings science to classrooms

Bryan Maestas, coordinator of the LANL Foundation Inquiry Science Education Consortium, Monitor photo.

A huge warehouse in Chimayo holds a treasure trove – boxes filled with materials needed to teach young students lessons about energy, matter, or other science topics.

Operated by the Los Alamos National Laboratory Foundation, a nonprofit with programs fostering educational opportunities in communities in the shadow of the national laboratory in Los Alamos, the 7-year-old program offers science education modules or “kits” for northern New Mexico elementary classrooms. (Full Story)

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