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In this issue:
A Fisher of Magnets
Dorfan Today: SSRL Downtime
DOE Launches "Science Accelerator"
Safety Firsts

SLAC Today

Monday - August 13, 2007

Andrew Fisher recently took measurements on a dipole destined for the second of two LCLS bunch compressors to be installed this fall. (Click image for larger version.)

A Fisher of Magnets

The naked truth about accelerators is that, without magnets, there would be no accelerators. Magnetic fields are used to steer, shape, focus, excite and otherwise modify the path of electrons and other subatomic particles throughout accelerator structures. Manipulating these beams of particles requires extreme precision, rendering even the slightest inconsistencies among otherwise identical magnets a big problem.

"Ideally, these should all be the same," says Andrew Fisher, a physicist working in SLAC's Magnetic Measurement Facility (MMF), while taking measurements on one of a series of electromagnets. "But in reality, they're all just a little different. What we're doing here is characterizing their fields."

Fisher and his colleagues at the MMF use a range of tools to map out and correct variations in a magnet's field strength and shape. The group currently spends a majority of time working with magnets destined for use in the Linac Coherent Light Source (LCLS). Recently, Fisher spent a few days measuring field distortions in a 5,000-pound dipole, a magnet designed for steering an electron beam. This particular dipole will soon be installed as part of the second of two bunch compressors for the LCLS.  Read more...

(Director's Column - Dorfan Today)

Last Monday, August 6, marked the beginning of this year's fall shut down for SPEAR3 at the Stanford Synchrotron Radiation Laboratory (SSRL). Next month, SLAC's main linac and the PEP accelerator will follow suit. Accelerator science is constantly evolving, and these annual shutdowns are anything but a time of rest. Maintenance and upgrade periods are essential for ensuring our research facilities remain state-of-the-art.

The 2006-2007 SSRL run ended on a very good note. Of the 5,533 hours of user beam time scheduled, 5,424 hours were delivered for a record 98% uptime. Overall, approximately 1,000 users conducted 1,300 experiments over the course of the last run. This would not have been possible without the focused efforts of the SSRL staff who worked to increase the reliability of the SPEAR3 ring and injector power supplies. Additionally, the injector achieved a big success at the end of the run. Operators kept the injector running until August 9 to establish photoelectrons in the booster, which occurred on Wednesday, August 8.

This year SPEAR3 will undergo a series of upgrades in the continued march toward operation at the design current of 500 milliamps. A number of safety interlock components will be installed in preparation for top-off injection, a necessary step before the increase in current. The insertion device for Beamline 4 will be moved to a new location to facilitate speedy construction of a new 500 mA-ready beamline during the next user run.

DOE Launches
"Science Accelerator"

The webpage may look simple, but the Department of Energy's new Science Accelerator offers an astounding amount of information.

Launched this summer, the Science Accelerator is a public search engine that combs all the Office of Science and Technical Information's key collections, including:

• Science Conference Proceedings
• DOE R&D Accomplishments
• DOE R&D Project Summaries
• Energy Citations Database
• EnergyFiles
• E-print Network
• Federal R&D Project Summaries
• Information Bridge

These collections enable web visitors to find out about ongoing research projects, explore significant DOE discoveries, learn about DOE Nobel Prize Winners, access and search scientific e-prints, sign up for alerts, locate science conference papers and proceedings, and more.

Safety Firsts

Safety Firsts Pay! I received a note from one of our readers telling me that while staying in a fancy hotel in San Francisco, he noticed that the slippery shower floor was hazardous, and after mentioning it to the hotel, had the cost of one day dropped from his bill. (For a small donation we might provide the name of the hotel.)

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