Actually, by keeping the room clean and requiring people to gown up, SiDet Center's Lab D maintains something closer to a class 10000 rank. Technicians at the SiDet Center are currently assembling 2700 silicon modules for CMS at CERN. Physicist Leonard Spiegel compares putting a silicon component into a detector to sending a satellite to Mars. "You don't want to send something up and find out too late that it doesn't work. So you test it a lot. Projects here are paced by all the testing." Technicians use computers to put together silicon sensors with readout microchips via microbonding. If problems are found during testing, technicians often must remove a microbond and repeat the entire process.

Soon, however, the SiDet Center will lose its claim as the cleanest rooms at the lab to an ILC cavity string assembly clean room being constructed at building MP9 as a part of the Cryomodule Assembly Facility (CAF). This series of clean rooms will include a class 1,000 "ante clean room," class 100 "clean storage area" and class 10 "assembly area." Here technicians will interconnect eight dressed RF cavities to create a cavity string that will eventually become part of a cryomodule. "The most important critical point is that each of these cavities was individually tested before they arrive to the assembly clean room," says Tug Arkan, Cryomodule Production Engineer. "Once they become a series of eight, there is no test for this string until the cryomodule is complete. When you put high RF power in the cryomodule, if there are particles inside the cavities, they'll create problems."

Not only must the ILC clean room be much cleaner, the work will be trickier. "In our clean room, we want to turn bolts and nuts, not really clean-room compatible work," explains Arkan. "You turn a nut, it's metal-to-metal. You'll get thousands of particles turning a nut on a screw thread." He estimates the cavity string assembly clean rooms will be ready by mid-April.
—Dawn Stanton

Workers are currently installing a raised, perforated floor (on left) at the future cavity string assembly clean room. Air flow from above fan filer units will push air into vents below to ensure continuous laminar air flow, which will help to keep the area clean as required by its clean room class.

BATAVIA — The Illinois Environmental Protection Agency has issued a permit violation notice to Fermi National Accelerator Laboratory regarding radioactive materials found in Indian Creek last year.

However, officials at Fermilab say there is no reason for alarm and that levels of that material have remained below detectable levels for months.

Small amounts of tritium, a radioactive isotope of hydrogen, were discovered in December 2005 by lab staff performing routine environmental tests, according to Judy Jackson, Fermilab's public relations director. The leak was traced to a pipe connecting two cooling pools.

Indian Creek begins on Fermilab property and runs southwest into a pond at the center of the Savannah subdivision at the corner of Kirk and Butterfield Roads.
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