August 6, 2004  
 

 

Galayda to Head New LCLS Division

By Shawne Neeper

To build the world’s fastest and shortest-wavelength x-ray laser, SLAC created a new Linac Coherent Light Source (LCLS) Division and named John Galayda as its Associate Director. Galayda brings nearly three decades of hands-on experience with accelerator-based light sources to this project to create the first-ever linac x-ray laser.

John Galayda, Associate Director for the LCLS Division (Photo by Diana Rogers)

After three years of planning the LCLS facility in collaboration with scientists at UCLA and Los Alamos, Livermore, Argonne and Brookhaven National Labs, Galayda will oversee the construction phase, guiding the laser’s growth from the drawing board into a new national user facility, similar in operation to SSRL. The newly-established LCLS Division will operate alongside the existing divisions at SLAC from initial setup and equipment procurements in 2004-05 through construction in 2005-08.

LCLS will use the last kilometer of the linac to speed tightly-packed bunches of electrons towards a 175-meter gauntlet of specially designed magnets. As these ‘undulator magnets’ bounce the electrons side-to-side, the electrons will emit x-rays into underground experimental stations. The x-rays are 10 billion times brighter and one thousand times shorter in duration than previously possible and promise real-time views into atomic and magnetic acrobatics. The femto-second x-ray pulses could even capture atoms shifting position and forming molecular bonds.

Construction of the super laser will cost approximately $315 million, Jonathan Dorfan said at his State of the Lab address. The project calls for the addition of a new electron injector branching into the two-kilometer point on the linac. New concrete tunnels, to house the undulator magnets and experimental facilities, will replace the current Final Focus Test Beam (FFTB) tunnel, and extend from the end of the current linac past the PEP Ring Road. “Since LCLS will use space currently dedicated to FFTB, proposals for FFTB replacements are in the works,” Dorfan said. “We require here the talents of the full lab.”

The LCLS Division will draw from existing SLAC personnel as well as external contractors and collaborators. That talent will have the leadership of an individual with exceptional experience.

 “[Galayda] is a world class physicist and brings to the LCLS a broad range of talents,” said LCLS chief engineer Mark Reichanadter (SSRL/LCLS). “When you talk about free-electron lasers and synchrotron radiation, he’s on the short list.”

LCLS is not the first high-energy light source that Galayda has helped to develop, nor even his second. Fresh from his graduate studies at Rutgers University in 1977—and inspired by a lecture from SSRL pioneer Herman Winick—Galayda joined a new project to build the National Synchrotron Light Source at Brookhaven.

“It was a small group. Everyone did everything,” Galayda said. He was up to his elbows in magnets, accelerator design and electron beam diagnosis until accepting a position as division director for the new Advanced Photon Source (APS) at Argonne in 1990. After 11 years with overall responsibility for design, construction, operation and upgrading of the APS accelerator systems, Galayda joined SLAC to help launch the LCLS in April 2001.

LCLS collaborations span organizations and lab sites. Specialized x-ray transport optics and diagnostics, under development at LLNL, must be optimized to deliver the most useful images to users. And the laser’s amazing brightness and femto-second pulse duration will demand the best possible performance from the SLAC linac.

“We’ll be relying heavily on past experience with the linac,” Galayda said. “The extremely short wavelengths of x-rays puts unprecedented demands on the beam quality.”

A new electron injector will create a high quality beam using an electron source based on SLAC, Brookhaven and UCLA collaborative R&D. Once the injector shoots electrons down the linac, the accelerator must compress the beam’s electron bunches through two magnetic bunch compressors developed at SLAC to generate the LCLS’s extremely short-duration x-ray pulses.

Once the system goes on line—in 2009, if all goes as scheduled—users from around the world can apply to perform experiments using the x-ray source. Several experiments, looking at protein structures and magnetic behavior of molecules, are already planned. But this is a technology with unprecedented potential that will push into new experimental frontiers.

“Some experiments are so hard that our outside partners will help us learn to do them,” Galayda said. “A lot of the techniques are not yet developed.” Building the LCLS is only the first part of the challenge.

 

The Stanford Linear Accelerator Center is managed by Stanford University for the US Department of Energy

Last update Wednesday August 04, 2004 by Emily Ball