Mechanical Systems Reliability Issues

Bobby McKee

Although the SLC damping ring system has seen many years of operation, it can be made to run reliably for many more years. A combination of closely regulated operation, careful maintenance, and selective component upgrades will result in a system level reliability necessary to effectively support the next generation of experiments. First of all, there needs to be operational stability. This will enable the components to run in a steady mode that minimizes thermal cycling and fatigue. When operational instability does occur, efforts should be made to isolate as much of the unaffected region from the resulting perturbation. Secondly, the engineers and the area managers need to plan and implement detailed maintenance tasks along with careful inspections. Focus should be on hardware known to degrade or move, such as bellows, bolted joints, hoses, and insulation. Experience has also shown us not to neglect alignment as an important inspection point. Thirdly and the most costly, is the upgrades to the hardware as replacements, repairs, and spares. What is essential with this category is that we make upgrades and spares very selectively. This requires that we log all failures and that we conduct subsequent failure investigations when necessary. With these log and the failure reports we can assess which components will require our fiscal resources. Currently, corrosion failures have been the most numerous. We are addressing one part of this problem by replacing the old coils with new ones in the south damping ring. Also, during this present SLC run cycle we replaced 3 radiation damaged kicker magnets. As a result we now have only 2 spare left on-the-shelf for the next run cycle. Since these kicker magnets have a very long fabrication lead time, their production rate will greatly impact the damping ring system reliability for the next series of run cycles.