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In this issue:
Engineering Big Upgrades
Science Today: SSRL: Five Images for the Price of One
Marguerite Shuttle to Increase SLAC Service
Photo of the Day: Progress Continues on Near Experimental Hall

SLAC Today

Thursday - March 8, 2007

The BaBar detector

symmetry: Engineering Big Upgrades

How do you renovate a delicate, irreplaceable detector? Very carefully.

During the last four months of 2006, the BaBar collaboration at SLAC successfully replaced a prematurely aging muon identification system. Creative and solid engineering played a big role in upgrading a detector that wasn't meant to be taken apart.

Jim Krebs, BaBar's chief engineer for mechanical operations, spent five years on the project. "We had to figure out how to take everything apart."

In August, crews opened the doors that protect the three-story-tall detector, exposing five layers of detection instrumentation and a nervous system of wires and cables. Graduate students disconnected and then lovingly tied, bundled, and organized the thousands of cables that blocked the way to the muon identification system. Read more...

(Daily Column - Science Today)

SSRL: Five Images for the Price of One

SSRL researchers helped to create a microscopic image, like this block letter "F," from its soft x-ray scattering pattern alone.

Scientists at the Stanford Synchrotron Radiation Laboratory (SSRL) have demonstrated a novel approach for improving the efficiency of an x-ray microscopy technique that may in particular prove beneficial for imaging radiation-sensitive objects such as biological samples. The findings, published in the October 2006 issue of Applied Physics Letters, should enhance imaging of sensitive samples and improve imaging with future ultra-short pulsed light sources, such as the Linac Coherent Light Source.

Using Fourier Transform Holography (FTH) with 1.58 nanometer wavelength "soft x-rays," the team of scientists extended the detection limit of high-resolution lensless imaging without increasing radiation exposure. FTH reconstructs a sample's microscopic image from its soft x-ray scattering pattern alone. With this lensless technique, coherent light scattered by a sample interferes with light scattered from a reference aperture to form a hologram. An image of the sample is analytically reconstructed from the hologram using a simple, direct process called a Fourier transformation. By illuminating several references with coherent x-rays, multiple holographic images of the specimen are reconstructed simultaneously.

The group found that compiling holographic images from multiple reference sources improves image quality by minimizing noise from imaging systems.

To learn more about this research see the full scientific highlight here.

Marguerite Shuttle to Increase SLAC Service

(Map - Marguerite shuttle)
(Click on image to view a real-time map of the shuttle's location.)

On Monday, April 2, Caltrain will institute slight changes on morning southbound trains to help improve on-time performance. In response to these changes, Stanford's Marguerite shuttle will also adjust its morning schedule, with Line A and Line B Clockwise shuttles departing the Palo Alto station at 7:54 a.m. and 8:54 a.m., to meet the newly adjusted 7:51 a.m. and 8:51 a.m. Caltrain southbound Baby Bullets.

In addition, the Marguerite will increase the frequency of its SLAC shuttle, with departures every 20 minutes. 

An updated schedule and route information will be posted on the Marguerite Route Map & Schedules webpage later this month.

To learn more about these changes, visit Stanford's Parking and Transportation website.

Photo of the Day:
Progress Continues on Near Experimental Hall

(Photo - NEH)
Bob Law, John Galayda, Jonathan Dorfan, and Mark Reichanadter stand in front of the Near Experimental Hall. (Click on image for larger version.)

Earlier this week, crews poured over 1,320 cubic yards of concrete for the foundation of the Near Experimental Hall (NEH). The NEH will serve as one of two experimental facilities for the Linac Coherent Light Source (LCLS). Crews hope to begin tunneling in the coming weeks.

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