Analysis of an interferometer with acoustic surface waves on one mirror.
It has been demonstrated that surface waves propagating on one mirror of an interferometer form an optical diffraction grating. Experimentally confirmed analyses of an interferomet er with 95.5% reflectivity mirrors now indicate that a surface wave power density of 0.028 mW/mm.MHz is required to diffract 1% of transmitted light into the first order beam. This power can be diminished by a factor of more than 20 by increasing the mirror reflectivity to 99%.
SURFACE WAVE COUPLING THROUGH A FLUID INTERFACE
A method to determine the coupling length for optimum transfer of surface wave energy from one substrate through an interface to a second substrate is presented. Less than 10 dB of energy loss is measured for coupling surface waves (20 MHz) on Y cut Z propagation (YZ) lithium niobate substrates through a water interface.
Long Ceramic Beam Tubes for Accelerator Magnets
The ceramic beam tubes for the fast and abort kickers and the bucker and pinger magnets used at Fermilab must meet a number of exacting requirements. The tubes must be long and sufficiently straight so as not to limit magnet design. They must have wall strength capable of withstanding the atmospheric and mechanical forces encountered during construction and operation. Vacuum tight ceramic to stainless steel transitions must be of reasonable cost; they must also withstand high temperature processing and remain vacuum tight to the 10/sup -9/ Torr range. To remove the possibility of static charge buildup each tube must have a surface coating of indium oxide applied to the inner wall. This thin coating is difficult to achieve and requires the most careful attention to detail. The methods used at Fermilab to achieve these goals are presented in this paper.