holds the cable to the ground as it is wound inside the box.
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
“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.
Japan, the lines will remain coiled and will breathe electric pulses
into the KEK kickers from the comfort of their wooden casing.