DEVELOPMENT AND TESTING OF CARBON FIBER COMPOSITE CHAMBER SUPPORTS FOR NSLS-II*

The NSLS-II Synchrotron Light Source, a 3 GeV electron storage ring currently under contruction at Brookhaven National Laboratory is expected to provide exceptional orbit stability in order to fully utilize the very small emittance of the electron beam. In order to realize this, the beam position monitor (BPM) pick up electrodes which are part of the orbit feedback system must have a high degree of mechanical and thermal stability. In the baseline design, this would have been accomplished by using flexible Invar plates to support the multi-pole vacuum chambers at the positions where the BPM pick up electrodes are mounted. However, it was later discovered that the close proximity of the Invar supports to the adjacent multi-pole magnets had an adverse affect on the magnetic fields. To mitigate this issue, we propose the use of carbon fiber composite in place of Invar as a low CTE (coefficient of thermal expansion) material. Here we show the design, devlopment and testing of thermally stable composite supports capable of sub-micron thermal stability.