This report seeks to "develop a practical method of evaluating the eddy diffusivity of heat transfer for liquid metals, so that it can be incorporated into the more or less standard theoretical methods to give heat transfer coefficients which are in reasonable agreement with experimental facts"--from introduction.

The theoretical and practical aspects of the accelerating mode (TM01) in iris-loaded waveguides have been covered extensively in many reports and publications. The pulse shortening observed in linacs and the possible application of an iris-loaded waveguides as the deflecting structure for rf particle separators stimulated the interest in the nature of higher order modes. Some experimental results on higher order modes in iris-loaded waveguides are available in references. Results of studies done at CERN are not yet published; they were however communicated to the authors and represented the basis of work done at Brookhaven. A preliminary account of BNL results was given in reference. The purpose of this report is to describe the model measurements which were necessary to determine the geometry of a brazed or electroformed prototype for a deflecting waveguide. At the same time, a systematic investigation of other than the deflecting mode was done to ensure a nondegenerate field solution at the operating frequency. The measurements are compared with computational results obtained on the IBM 7090 at BNL.