Development of a Traveling Wave Accelerating Structure for a Superconducting Accelerator

Superconducting radio frequency (RF) technology has been recommended recently as the basis for the accelerating structures of the International Linear Collider (ILC). The present state of the art in superconducting structures has achieved a gradient of 35 MV/m. This project will design, develop and demonstrate the Superconducting Traveling Wave Accelerator (STWA), a new experimental device that will further increase the gradient by a factor of 1.2-1.4. The STWA structure will operate at the same surface magnetic and electrical field magnitudes as the TESLA cavity surface to avoid undesirable superconductivity break down. In Phase I, theoretical studies were performed in order to: (1) optimize the proposed design by minimizing the surface fields inside the cavity of the structure, (2) make the design compatible with existing technology, and (3) determine the maximum achievable gain in the accelerating gradient. Phase II will develop a preliminary engineering design of the high-gradient STWA structure suitable for ILC application. Commercial Applications and Other Benefits as described by the awardee: The superconducting accelerating structure should allow the total length of the linear collider to be reduced by 20-40%, with a corresponding reduction in construction costs. The structure would be an inexpensive solution that permits the use of currently available accelerator components.