DESIGN OF A LOW-COST, LOW MAGNETIC-SUSCEPTIBILITY, ULTRAHIGH-VACUUM COMPATIBLE, FLANGED ELECTRICAL BREAK

At Brookhaven National Laboratory, the g-2 experiment, a muon storage ring, requires a totally nonmagnetic vacuum system. All the vacuum com ponents must have a low magnetic Susceptibility. The design of the bea m vacuum system requires hanged electrical breaks on pumping manifolds in order to prevent ground loops. The electrical breaks developed at Brookhaven consist of a ceramic disk clamped between two Conflat flang es. A nonconductive retaining ring is used to support and center the c eramic disk and Seals with respect to the flanges. Two Helicoflex Delt a seals are used to seal the flanges to the ceramic disk which has met allized surfaces in the seal area. Threaded rods which are electricall y insulated from the flanges with bushings are used to provide the cla mping force necessary to compress the vacuum seals. The assembly remai ns leak tight after repeated bakeouts up to 200 degrees C. This design offers several advantages over commercially available Conflat hanged ceramic breaks. These breaks do not use Kovar and are totally nonmagne tic. In addition to the cost being lower the overall length of the bre ak is much shorter than commercial breaks. The same design concepts ca n be used for different sized Conflat flanges and for other types of f langes. The detailed design and the performance of this break are pres ented in this article.