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In this issue:
EXO on the Road
Congratulations to the 2007 Environmental Stewardship Champions
symmetry: Tesla in Paradise
Crab Cavities Operated Successfully for First Time

SLAC Today

Friday - July 6, 2007

The first module leaving Stanford yesterday morning. (Click on image to see a photo gallery of the move.)

EXO on the Road

On a small side street on Stanford's main campus, just across from a bustling construction site, a transport company loaded four shipping containers onto trucks yesterday. The activity may well have blended into the background for a casual observer, but for Giorgio Gratta and a handful of others, it marked a milestone in the search for knowledge about neutrinos.

"Today, we completed an integral step in the complex process that will take the prototype Enriched Xenon Observatory [EXO] to the bottom of a mine shaft in New Mexico," said Gratta, the EXO project leader. "But we're not done yet; there are still two other truck journeys, a mine shaft, and shifting salt to think about."  Read more...

Congratulations to the 2007 Environmental Stewardship Champions

(Photo - ESCs)
Photo courtesy of Diana Rogers.
(Click on image for larger version.)

Yesterday afternoon, SLAC presented the 2007 Environmental Stewardship Champion certificates to employees who have made noteworthy efforts in pollution prevention and environmental stewardship. Congratulations to these employees!

Tesla in Paradise

(Photo - Tesla coil)
Photo courtesy of Jason Chen,

Even in the company of a two-story nose-picking machine, human cupcakes, battling robots, and power-tool drag races, the giant Tesla coil stands out.

Maybe it's the loud buzz and crackle of artificial lightning bolts, writhing like fiery serpents from the top of the thing.

Maybe it's the hint of danger: More than one million volts! Stay back behind the ropes, and turn off your cell phone!

Paulina Shearer and her brother, Andrew, watched wide-eyed, hands over their ears, as a volunteer, safely enclosed in a clunky metal suit, came forward to do battle with the flashing electrical arcs (Look folks, he's safe! Give him a hand!).

"It was cool," six-year-old Paulina said, "but kind of freaky."

Crab Cavities Operated Successfully for 1st Time

A CAD drawing of a crab cavity. (Image courtesy of KEK.)

A team of accelerator physicists at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, has achieved effective head-on collisions of electrons and positrons using new devices called "crab cavities" during the spring operation period of the KEKB accelerator. This success will pave the way to increase KEKB's luminosity, which is already the world highest, to an unprecedented level.

At KEKB, beams of electrons and positrons collide at nearly the speed of light and annihilate into a state of pure energy. These collisions produce pairs of particles called B mesons and anti-B mesons. These mesons have several thousand decay modes; therefore, it is essential for the experiment to have as many pairs as possible. The rate of collisions, called luminosity, is the most critical parameter for the successful operation of KEKB.

The electron and positron beam bunches cross at an angle of 1.3 degrees at KEKB. This non-zero crossing angle is one of the novel design features of KEKB, providing effective beam separation at the collision point without a high level of background noise in the detector. To boost the luminosity further, it is necessary to tilt the bunches of electrons and positrons for effective head-on collisions while retaining the crossing angle.  Read more...

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