High Power S-Band Vacuum Dry Load for SLAC Linac using Innovative Highly Conductive Materials and Novel Manufacturing Technologies.

We realized in discussions with SLAC engineering that a serious problem lies in the antiquated technology of the S-Band RF loads. The load components on the current SLAC system were designed, in some cases, 40+ years ago to terminate 8-10 MW peak power using 200 micrometers of coated Kanthal alloy as the high power absorber. Kanthal wire was flame-sprayed onto a base material. This technology was utilized to create an RF power absorption layer. These loads performed adequately for many years but now are stressed and not capable of supporting higher power klystrons that emit peak powers up to 67 MW levels. Furthermore, they do not support the SLED mode of operation. The only current supplier of these (under-rated) loads is a Japanese firm which sells them for $15K each. Our proposal will clearly detail the INTA approach, which will be based on a close collaboration with SLAC load designers. To achieve the most economical and functional load design, we would like to stay consistent with a proven technology, where low conductive materials will be utilized. For example, we will duplicate the flame sprayed thin Kanthal layer technique and compare the RF properties against that of bulk Kanthal tubing material as well as other modern low conductive candidates for the new SLAC linac RF loads. This is a robust, simple, and relatively inexpensive technology where highly resistive materials are used in load systems. In each case a proposed load design to terminate 20+ MW peak RF power will be examined from technological aspects focusing on cost and ease of manufacture. Commercial Applications and Other Benefits: The SLAC two mile S-band linac utilizes approximately (1K) one thousand, dry vacuum RF loads. Replacement of these old loads would be an optimal scenario for a small commerce company like INTA Technologies. The INTA/SLAC proposed RF load design can easily be scaled for many other accelerators worldwide. This new technology is also applicable in medical clinac systems as well as industrial applications.