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In this issue:
SPEAR Springs to Life, With Upgrades
People Today: Scott Wenholz on Music, Sports and Physics
LSST Mirror Lifted

SLAC Today

Wednesday - November 5, 2008

SPEAR Springs to Life, With Upgrades

PJ Boussina monitors the newly upgraded booster-to-SPEAR transfer system in the SPEAR control room.
(Click on image for larger version.)

The Stanford Synchrotron Radiation Lightsource is spending this week gearing up for a new season of science, with the first round of user experiments set to commence on November 10. After weeks of downtime, the lightsource now boasts a set of long-awaited upgrades that improve both safety and efficiency in the march toward operation of the accelerator at its full design potential.

SPEAR3, commissioned in 2004, is designed to operate at 500 milliamperes (mA) of current, which will provide a very bright, steady source of X-rays. But a series of required technical upgrades has meant that so far the accelerator has run at a much lower current of 100 mA. Now, thanks to the recent installation of components in the transport line connecting the booster ring and the main storage ring, SSRL is several steps closer to realizing the full operating current.

Until now, the vacuum systems of SPEAR and the transfer line were separate, requiring electron pulses to pass through a series of thin steel windows. That worked fine at 100 mA, but a unified vacuum system is required to achieve 500 mA. After months of hard work, the two vacuum systems are now connected, promising much more efficient operation of the beam.

SSRL will take the next steps this spring when a number of beamlines will be provisionally operated with the accelerator at 500 mA.

(Weekly Column - Profile)

Scott Wenholz on Music, Sports and Physics

Wenholz has played a variety of musical instruments since he was 8. (Photo courtesy of Scott Wenholz. Click for larger image.)

"People think it must have been a big change going from music to physics, but it really wasn't," says Scott Wenholz. "There's a mathematical side to music. Einstein played violin. I'm amazed at how many physicists are great musicians." Wenholz studied physics and public health, and has also played drums, percussion, guitar, bass and multiple brass instruments since he was 8. "It's who I am. I just do the things I enjoy doing."

Wenholz works in SLAC National Accelerator Laboratory's Department of Energy Site Office as a health physicist. Acting as a sort of liaison between the DOE office and SLAC's radiation and industrial hygiene groups, he's responsible for making sure the groups are meeting all DOE safety standards. His bachelor's degree in physics from Fresno State and Graduate work in public health help him understand the threats posed by hazardous materials on the SLAC campus. "The [radiation and industrial hygiene] groups run a tight ship, which makes my job a lot easier," he says. "I like doing something that really matters. That makes a difference."  Read more...

Mini Benefits Fair Today

A mini benefits fair will take place today in the Panofsky Auditorium Breezeway between 11:00 a.m. and 2:00 p.m. with representatives from HIP, BeWell @ Stanford, the WorkLife office, Faculty & Staff Help Center and the Energy Employees Compensation Resource Center.

LSST Mirror Lifted

(Photo - LSST mirror being lifted)
The mirror blank for the Large Synoptic Survey Telescope has been successfully lifted from its furnace hearth, installed into a turning ring, and tilted to a vertical position. (Image by Jeffrey Kingsley, University of Arizona Steward Observatory. Click for larger image.)

The 8.4-meter, single-piece primary and tertiary mirror blank for the Large Synoptic Survey Telescope has come out of hibernation. After taking three months to cool down from its formation, the mirror was lifted from its horizontal resting place in the furnace to a vertical position, using a custom-made device (red in the photograph). Now crews will clean excess glass and debris out of the supportive honeycomb structures on the back of the mirror. This will reduce the weight of the mirror from 46,500 kg (102,300 lbs) to 16,600 kg (36,520 lbs).

The next step for team members at University of Arizona's Steward Observatory Mirror Lab in Tucson will be polishing the mirror, a process that will take more than two years to complete. LSST scientists have scheduled installation of the mirror for January 2012. It will be the largest two-surface optical mirror ever made from a single substrate.

SLAC National Accelerator Laboratory Professor David Burke says this milestone is exciting for everyone involved in LSST. "SLAC is the [Department of Energy] lead for the LSST project, although we work mostly with the camera. New updates on the project are of interest to everyone. From our point of view a neat part of this is the private funding. That's a unique thing for SLAC-related projects." Private donations from the Charles Simonyi Fund and Bill Gates, to name a few, have supported creation of the mirror.


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