SLAC Today is available online at:
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In this issue:
From the Chief Operating Officer: The Next SLAC Agenda
Astronomy and Astrophysics Decadal Survey Released
New Common Link Found for High-temperature Superconductors
Fermi Gamma-ray Space Telescope Spies a Distant Nova
Word of the Week: Ice Cream (Social Today)

SLAC Today

Friday - August 13, 2010

From the Chief Operating Officer:
The Next SLAC Agenda

(Photo - Alexander Merola)
(Photo by Linda Cicero.)

You may be aware that SLAC Director Persis Drell, with the associate laboratory directors, recently presented three SLAC objectives to the Office of Science. These objectives that define our future success are to: (a) continue to be a premier accelerator laboratory; (b) ensure our significant role in targeted areas of particle physics, particle astrophysics and cosmology; and (c) dramatically grow our role as a photon science laboratory.

In that regard, the SLAC ALDs are currently identifying the detailed deliverables that underpin the accomplishment of these objectives. These will be codified as the SLAC Agenda and will be updated annually as SLAC's most important priorities.  Read more...

Astronomy and Astrophysics
Decadal Survey Released

Large Synoptic Survey Telescope and Wide-field Infrared Survey Telescope get top ranking

(Photo)
WFIRST (top) the LSST (bottom). (Images courtesy of NASA-GSFC and LSST Corporation, respectively.)

The National Academy of Sciences' National Research Council today released New Worlds, New Horizons in Astronomy and Astrophysics, the result of a two-year process, involving hundreds of scientists, that ranks priorities in U.S. astronomy and astrophysics for the next decade. At the top of the list for large-scale missions are the ground-based Large Synoptic Survey Telescope, or LSST, and a space-based observatory called the Wide-field Infrared Survey Telescope, or WFIRST, which is based on proposed designs for the Joint Dark Energy Mission. 

Read more...

New Common Link Found for High-temperature Superconductors

(Photo - James Analytis, Jiun-Haw Chu and Ian Fisher at Stanford )
From left: James Analytis, Jiun-Haw Chu and Ian Fisher. (Photo courtesy Ian Fisher.)

A research group led by Ian Fisher of the Stanford Institute for Materials and Energy Science, a joint SLAC-Stanford institute, has found an odd property in a particular material belonging to a family of high-temperature superconducting compounds called iron pnictides: under certain conditions, electrons flow through the material much more easily in one direction than the other.

The research is covered in a paper appearing online today in the journal Science. The paper discusses not only this imbalance in conductivity, called an "in-plane anisotropy," but also the fact that the group's research required some innovative experimental techniques, including the development of a completely new tool for "detwinning" miniscule crystals.

"In its own right, the question of what's causing this phenomenon of electronic anisotropy is intriguing, and is something that we really want to understand," Fisher said.

But it's what the paper doesn't say that that has him truly excited.  Read more...

Fermi Gamma-ray Space Telescope Spies a Distant Nova

(Image - FGST image before and during the nova)
Fermi's Large Area Telescope saw no sign of a nova in 19 days of data prior to March 10 (left), but the eruption is obvious in data from the following 19 days (right). The images show the rate of gamma rays with energies greater than 100 million electron volts (100 MeV); brighter colors indicate higher rates. (Image: NASA/DOE/Fermi LAT Collaboration.)

Astronomers using the Fermi Gamma-ray Space Telescope have detected gamma rays from a nova for the first time, a finding that stunned observers and theorists alike. The discovery overturns the notion that novae explosions lack the power to emit enough gamma radiation to be spotted from Earth.

"In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the sun every year," said Elizabeth Hays, a Fermi deputy project scientist at NASA's Goddard Space Flight Center. "But compared to other cosmic events Fermi sees, it was quite modest. We're amazed that Fermi detected it so strongly."

Gamma rays are the most energetic form of light, and Fermi's Large Area Telescope detected the nova for 15 days. Scientists believe the emission arose as a million-mile-per-hour shock wave raced from the site of the explosion.

A paper detailing the discovery will appear in the August 13 edition of the journal Science.

The nova, located in a star known as V407 Cyg in the constellation Cygnus, was first spotted by amateur astronomers in Japan on March 11. They sent word to Kyoto University researchers, who in turn notified astronomers around the world for follow-up observations. Separately, on March 13, the Fermi LAT picked up a significant detection in Cygnus. The LAT team, including Naval Research Laboratory astrophysicist Teddy Cheung, formerly of the Kavli Institute at SLAC and lead author of the study, learned that the system had undergone a nova outburst.

"When we looked closer, we found that the LAT had detected the first gamma rays at about the same time as the nova's discovery," Cheung said. Read more and see an animation of the nova from NASA...

(Photo - cherry ice cream)
 Come enjoy some ice cream at today's Pause ice cream social, 2–4 p.m. in the Panofsky breezeway. (Photo by Heidi Swanson.)

Word of the Week:
Ice Cream

Pause Ice Cream Social Today

It's America's favorite semi-solid foam, a delectable mix of ice crystals, air bubbles and globules of milk fat slow-churned into confectionary perfection. The recipe for ice cream might be simple, but the freezing process has taken centuries to master. The key to a balanced texture that is creamy, smooth and firm is to mix sweetened cream as it freezes. Water from the cream will turn into ice crystals, which in turn are coated by the concentrated fluid left over. The churning process introduces air bubbles into the frozen matrix, making the mixture softer and easier to eat. Try some for yourself at the Pause ice cream social, today from 2 to 4 p.m. in the Panofsky breezeway.

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