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In this issue:
SLAC Light Sources, the Brilliant and the Bold
Colloquium: Biophysics - Breaking the Nanometer Barrier
Kavli Building Dedication This Afternoon
Loop Road Status Update
Teamwork Restores Beam in SPEAR3

SLAC Today

Friday - March 17, 2006

(Image - synchrotron)
Components of a synchrotron light source typically include (1) an electron gun, (2) a linear accelerator, (3) a booster synchrotron, (4) a storage ring, (5) beamlines, and (6) experiment stations. (Image courtesy of the Australian Synchrotron and Michael Payne)

SLAC Light Sources, the Brilliant and the Bold

SLAC is flush with light sources. SPEAR3 and SPPS are operating, and LCLS is under construction. This acronym soup of machines has in common their end product: photons of x-ray wavelength that can see into materials to make insightful images. They are also dramatically different from each other.

Here's a brief primer:
SPEAR3 is a circular storage ring. Electrons radiate photons, from ultraviolet wavelengths through hard x-rays, when magnets force them to make sharp changes of direction. The average wavelength of the photons is one Angstrom, just the right distance to take snap shots of molecular complexes.

The machine was completely upgraded and reopened at the beginning of 2004 as a "third-generation" light source, capable of brighter x-ray beams and higher current. SPEAR3 will continue to be an invaluable research tool for years to come.  Read more...

Colloquium Monday

Biophysics: Breaking the Nanometer Barrier

(Image - Optical tweezers) Optical tweezers help researchers watch RNA polymerase in action

A new field of scientific exploration—single molecule biophysics—is currently reshaping and redefining our understanding of the mechanochemistry of life. The development of laser-based optical traps, or "optical tweezers," has allowed for physiological assessments of such precision that bio-molecules can now be measured and studied one at a time.

In this colloquium, Professor Block will present findings based on his group's construction of optical trapping instrumentation that has broken the nanometer barrier, allowing researchers to study single-molecule displacements on the Angstrom level.

Focusing on RNA polymerase, the motor enzyme responsible for transcribing the genetic code contained in DNA, Block's group has been able to measure, in real time, the motion of a single molecule of RNA polymerase as it moves from base to base along the DNA template. A remarkable opportunity to gain insight into one of the most fundamental biological processes of life, this colloquium cannot be missed!

The colloquium will take place at 4:15 p.m. on Monday, March 20 in Panofsky Auditorium. All are invited to attend.  Learn more...

Kavli Building Dedication This Afternoon

Don't forget! This afternoon from 3:00-4:30 p.m., all staff and users are invited to explore the Kavli Building. Come see the new auditorium, KIPAC's new visualization lab and the impressive views from the offices. Learn about KIPAC science from the researchers themselves! Light refreshments will be served.

Loop Road Status Update

Although the Kavli Building officially opens today, the closure of the Loop Road near the front gate will continue through early April. Construction crews will return to SLAC on Monday morning to put the finishing touches on the building and repair the road itself, which was damaged during construction.

"The road is still somewhat unsafe," said KIPAC's Ziba Mahdavi. "We're excited about the new building and thank everyone at SLAC for their patience as we finish the project."

Teamwork Restores Beam in SPEAR3

Thanks to SLAC teamwork, a problem with a high voltage power supply for the SPEAR3 booster RF system was rapidly addressed last week. SSRL is indebted to all who helped facilitate the repair.

Although the exact nature and severity of the power supply problem were not readily apparent at first, the SSRL Electrical Systems and Mechanical Services groups planned for various scenarios to make anticipated repairs.   Read more...

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