July 15, 2005  


A student holds the cable to the ground as it is wound inside the box.
(Both Photos by Diana Rogers)

Summer Student Square the Circle at SLAC

By Francoise Chanut

How many summer students does it take to coil 693 feet of RG220 coaxial cable neatly inside a square box? Five, according to John Krzaszczak (ESD).

He recently rounded up five summer students and four SLAC employees, who together loaded three cables totaling approximately 700 pounds into an 800 pound wood crate. The cables will be shipped to Japan later this summer.

It was not easy. On top of being heavy, the RG220 cable is stiff because it houses a copper wire a quarter of an inch thick. Moreover, it must not be twisted during handling, nor should it be coiled too tightly before shipping, because that would squeeze the wire and compromise its performance at high voltage.

The solution came in the form of an 8’x 8’ wood crate Krzaszczak and colleague Doug McCormick (ILC) designed specifically for this shipment—a case of “thinking inside the box,” Krzaszczak said.

“The crate has castors and we spun it around while removing the cable off the factory reel,” he explained. The result was a stack of three spirals with a comfortable curvature (at least a three-feet radius) inside the square crate—a snuggly squaring of the circle.

“It only took about an hour,” said Brian Domitilli (ESD), a UC Santa Cruz junior in legal studies who doesn’t recoil from physical work.

The three 231-foot cables will provide the Pulse Forming Lines (PFL) of a kicker system that SLAC staff are installing on the damping ring at KEK in Japan. The kickers will move electrons in and out of the linear accelerators, sending them to the ring where they become focused into sharp beams. Kickers work in pulses whose duration depends on the PFL’s length. The KEK ring uses pulses of 300 nanoseconds, which requires a PFL of exactly 231 feet.

Back Row: John Krzaszczak (ESD), Juan Cruz (NLC), Edger Cruz (NLC), Brian Domitilli (ESD), Tony Beukers (ESD) and Doug McCormick (NLC). Front Row: Neil Williams (ESD), An Nguyen (ESD) and Sean Fong (ESD).

Krzaszczak and his student coordinator Tony Beukers (ESD), a UC Davis physics senior spending his fourth summer at SLAC, choreographed the packing. In keeping with the Integrated Safety Management System (ISMS), the team went through a safety evaluation before setting down to the task. Then, Domitilli hauled the cable off the reel while Sean Fong (ESD), a UCSC sophomore, and Neil Williams (ESD), a UCSC computer science student, stretched it out on the floor to measure it, and meted it out to someone standing in the crate. That person set the cable inside guiding grooves while the rest of the crew, including An Nguyen (ESD), a recent high-school graduate, rotated the crate. It took about ten full spins to coil each line inside the crate.

Once in Japan, the lines will remain coiled and will breathe electric pulses into the KEK kickers from the comfort of their wooden casing.


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

Last update Friday July 15, 2005 by Topher White