MA and PA buses almost ready to roll into NIF
By Sue Stephenson
Newsline correspondent
At the end of January, the first pair of amplifier buses was produced
in the high bay of Bldg. 381 and shipped to Bldg. 493, a storage area
for the National Ignition Facility (NIF).
These massive enclosures will house the first bundle of NIF amplifiers.
The main amplifier, MA, is the larger one, and the power amplifier, PA,
is the smaller one. This spring these amplifier buses will be installed
into Bldg. 581, NIF.
This effort involved not only the NIF Amplifier Assembly team and Flashlamp
Window Assembly team, it also required the assistance of Plant Engineering/NIF
riggers to operate the overhead crane, straddle lifter and tugs, and Security
Police Officers to control traffic on Outer Loop.
"I’m amazed when I think of all the problems this team overcame
due to good planning and hard work. It’s a credit to their talent
and dedication that a job this complicated was accomplished safely and
on such an aggressive schedule," says Amplifier Associate Project
Manager Doug Larson.
One difficulty the Amplifier Assembly team overcame was to assemble these
school bus-size amplifiers with the great alignment accuracy required
by NIF. Parts inside the amplifiers were aligned and fixed within one
fourth of a millimeter.
Some of the parts, 72 flashlamp window assemblies, were put together in
the Optics Processing Lab (OPL) in Bldg. 391. Then they were carefully
transported to the high bay in Bldg. 381 where they were inserted into
the amplifier bus.
"All of the large NIF optics will pass through Bldg. 391’s OPL,"
said Gina Bonanno, associate project manager for Assembly, Installation
and Refurbishment, "and this is the first production run performed
in that facility. Jim Fair the OPL manager and the two production leads,
Guy Robitaille and Sue Frieders led the team that worked very hard to
make this happen."
"This is the first step. A total of 1,728 flashlamp window assemblies
will be required for NIF. Typically, the Lab does not produce large quantities
of anything," Bonanno said, "so we’ve been challenged to
not only build complex opto-mechanical assemblies, but to do it in large
quantities while meeting strict standards of quality. I’m impressed
with how well the team has performed."
Once the amplifier is assembled it will not be cleaned again. So all of
the assembly work is done in Class 100 clean rooms: Bldg. 381 high bay
and the Optics Processing Lab in Bldg. 391. A Class 100 clean room refers
to the quality of air: no more than 100 particles greater in size than
half a micron per cubic foot of air.
In addition to working in a clean environment, the assembly teams must
keep the surfaces of the various parts with which they work at Level 83
cleanliness. This means there are no more than 900 particles per square
foot that are greater in size than five microns on the surface of the
items. It is difficult to see a spec of dust that is five microns. The
diameter of a human hair is 100 microns.
These super clean requirements are necessary while building, moving and
attaching the amplifiers to the NIF system. Even the transport container
that stores the massive frames for the amplifiers is specially designed
to keep them clean, temperature controlled and precisely aligned while
they wait their turn to be placed in NIF.
"This is the culmination of five years of planning and hard work
by many people," said Buzz Pedrotti, lead engineer of NIF amplifier
mechanical systems. "The responsible engineer, Ernie Moor, production
manager Tom Kohut, and their teams of engineers, designers, coordinators,
technicians, buyers and suppliers have done a remarkable job of satisfying
many difficult requirements for these large structures.
"They have created a production line that safely produces clean,
electrically isolated, leak-free enclosures assembled to very tight tolerances.
We are proud of our team and delighted that the factory is producing,"
he said.