No abstract

The fabrication of a muffin-tin planar accelerator structure for operation in the 90 GHz range is discussed in Reference. [1]. Fabrication problems subsequently encountered led us to consider an alternative structure, a structure which can be thought of as a muffin-tin with the sides removed and replaced by a pair of side chambers which act as side terminations (Fig. 1). With the side chambers removed, the structure when viewed from the side presents two periodic arrays of vanes facing one another from above and below the beam plane and which extend towards the beam plane from upper and lower plane metallic surfaces. The vane pairs are the analogs of the beam iris in cylindrical structures, and the space between the irises and terminated by the upper and lower plane metallic surfaces correspond to the cavities. Because the general appearance of this view is zipper like, we will refer to the structure as the "zipper" structure. The side chambers are envisaged as extending with uniform cross section from the input to the output cavities.

Results are presented for fabrication and test of a WR10 waveguide window, for use in ultra-high vacuum at 91.4 GHz. Low-power bench measurements are compared with analytic and simulation results. Operation at ≈ to 4 kW peak power, duty factor 10 -6 and 10 -9 -scale vacuum is noted.

We describe the design, fabrication and bench-study of a mm-wave cavity employed as a relativistic klystron output structure. The OFE copper cavity was prepared by electrodischarge machining and diffusion bonding, cleaned, and tuned to 91.4 GHz. Measured cavity characteristics are presented and compared with theory, including quality factor, Q, coupling parameter ß, scattering matrix S 11 , and axial electric field profile E z . This work provides the basis for understanding of the cavity as a transfer structure.

We estimate the short-range wake elds in the W-band active matrix linac of a 5-TeV collider, and demonstrate that for the assumed 60-pC bunch c harge and 10-m rms bunch length they are acceptable. Abstract. We estimate the short-range wake elds in the W-band active matrix linac of a 5-TeV collider, and demonstrate that for the assumed 60-pC bunch c harge and 10-m rms bunch length they are acceptable.