Dielectric-Lined High-Gradient Accelerator Structure

78070S The realization of a future multi-TeV electron-positron collider rests, among other factors, upon the development of structures that can sustain high acceleration gradients. This project will develop a rectangular waveguide containing planar dielectric slabs as a high-gradient accelerator structure. This Ka-band, dielectric-loaded rectangular accelerator structure will have high shunt impedance and relatively small radio frequencey (RF) electric fields on conducting surfaces, and should be capable of providing accelerating gradients well above 100 MV/m. In Phase I, an anaysis for a rectangular Ka-band waveguide containing planar dielectric slabs will be carried out to optimize the RF field distributions, so as to provide high shunt impedance with minimum fields on surfaces or dielectrics. Field simulations will be carried out to obtain an optimum design for the RF input waveguide couplers for a 34-GHz cavity test structure. Properties of artificial CVD-grown polycrystalline diamond will be measured to assure the suitability of this low-loss, high-dielectric-strength material for this application. Particle simulations will be conducted to appraise beam emittance preservation, energy spread, and intrinsic focusing, during beam acceleration in this structure. Construction, testing, and evaluation are planned for Phase II. Commercial Applications and Other Benefits as described by the awardee: Future construction of a multi-TeV electron-positron collider for high-energy physics experiments would entail the procurement of thousands of accelerator structure modules. Successful results from this project could place the dielectric-loaded accelerator structure in contention for this procurement, with a potential value of hundreds of millions of dollars.