SLAC Today is available online at:
In this issue:
Stopping Stray Electrons in Their Tracks
Dorfan Today: LCLS is Concrete
PPA Information Summit Comes to SLAC
Safety Firsts

SLAC Today

Monday - May 7, 2007

Stopping Stray Electrons in Their Tracks

This collimator box folds in half in the middle, forming slots with a different collimator in each. To take measurements, experimenters move the box to give each collimator a turn in the beam's path.

Set out before an experiment, the collimators resemble a miniature skateboard park with sloping ramps and blocks with killer angles. But unlike at the skateboard park, the collimators do not welcome mavericks. Their job is to stop the rebels: electrons that refuse to travel in tight formation with the rest of the electrons in a beam of particles.

Collimators are pieces of metal fitted inside a beam pipe, allowing the focused core of the beam through while blocking stray electrons (or positrons). The job of the International Linear Collider (ILC) group is to develop and test collimators that effectively deal with the nonconformists without disrupting the rest of the beam.

"Even during perfect operations, you have a halo of particles—a big fuzz of low charge that will reduce efficiency and increase noise if it gets into the detector. For ILC, we need collimators that can also absorb the full energy of the beam if something goes wrong, to keep the beam from damaging the detector," said Steve Molloy, a postdoc in the ILC Experiments and Prototypes group.  Read more...

(Director's Column - Dorfan Today)

LCLS is Concrete

Planning for the LCLS has taken years of careful work by hundreds of people. There have been countless meetings, PowerPoint presentations, CAD drawings, budget spreadsheets, and safety reviews but now the LCLS has transformed from something virtual, on paper and on the screen, into something concrete – in fact 6,000 cubic yards of concrete.

Including civil construction and hardware, LCLS construction progress is now approaching the halfway point. SLAC's familiar topography has begun to metamorphose before our eyes. The new permanent structures taking shape across the lab are examples of SLAC's evolving identity as our mission and focus shifts toward the future.

Civil construction has now reached cruising speed and the visible outline of the LCLS is now clearly evident. In the last months, concrete workers have poured nearly 6,000 cubic yards of concrete for what will be the Near Experimental Hall and the Beam Transport Hall. Last week alone more than 1,600 cubic yards were poured, continuing this week as portions of the roof for the Beam Transport Hall are put into place.

Tunnel excavation is now underway on two fronts. Crews are advancing 8 feet per shift on each front and have progressed over 235 feet as of the end of last week. Digging commenced from the Research Yard beneath the overlook just a few weeks ago, and access tunnel excavation behind the Collider Hall has been in progress for nearly two months. In the coming weeks a second tunneling shift will be added and subterranean excavation is scheduled to begin on the Far Experimental Hall.

Take a moment sometime to look at the construction progress and you'll be struck at how rapidly the landscape is changing. You can watch live streaming video of the activities through either of two strategically positioned webcams, and the interactive LCLS Dashboard  provides a graphical overview of progress on the entire project.

I am deeply encouraged by the strong sense of gathering momentum surrounding the LCLS project. This is truly an historic undertaking, one that will usher in an exciting new scientific era at SLAC. It has taken many years of planning and coordination to get to this stage, and it is a thrill to be witnessing the fruits of such hard work. Special thanks to everyone involved in all aspects of the LCLS project, to Turner Construction and to the 150 construction workers now on site.   More than that, I believe that everyone at SLAC can share a well-deserved sense of pride in this accomplishment as it unfolds.

PPA Information Summit Comes to SLAC

What will physics be like five years from now? New colliders will be under construction and new particles may have been discovered, but what about the way physicists communicate these exciting events? The SLAC Library has organized the Particle Physics and Astrophysics (PPA) Information Summit to dream, define, and begin to develop the next generation of particle physics and particle astrophysics information services.

Attendees will include representatives of key PPA information resource providers: the Stanford Public Information REtrieval System (SPIRES), the Particle Data Group, CERN, NASA's Astrophysics Data System, Cornell University's, the American Physical Society, the Insitute of Physics, Elsevier, the Journal of High Energy Physics , PhysMathCentral, and Springer/EPJ scientific communication.

SLAC researchers and staff are welcome to attend the morning session on Thursday, May 10, 2007, in which Stan Brodsky will moderate a panel session featuring talks by Google's Anurag Acharya, the Kavli Institute for Particel Astrophysics and Cosmology's Tom Abel, CERN's Gigi Rolandi, and SLAC's Michael Peskin. Each speaker will share his vision of the evolving research landscape and how it impacts scientific communication. The session will take place from 8:30 a.m. until 12:00 p.m. in Panofsky Auditorium.

For more information, please contact the SLAC Library at 650-926-2411.

Safety Firsts

Since we are all now adept at both recognizing and controlling hazards, if you were going to attempt something clearly established as very dangerous, possibly deadly, without bringing with you anything to help you cope with something going wrong, would you be willing to pay extra for a small "get out of jail" device that might keep you from being seriously injured or killed? How much would you be willing to pay?

Events (see all | submit)

Access (see all)

(see all | submit)

 Lab Announcements

Community Bulletin Board

News (see all | submit)

dividing line
(Office of Science/U.S. DOE Logo)

View online at