Design, fabrication, room temperature RF test of 1050 MHz, β = 0.49 single cell large grain niobium cavity

Abstract

BARC is developing a technology for the accelerator driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U233. Design and prototyping of a superconducting medium velocity cavity has been taken up as a part of the ADSS project. The cavity design for β = 0.49, f = 1050 MHz has been optimized to minimize the peak electric and magnetic fields, with a goal of 5 MV/m of accelerating gradient at a Q > 5×109 at 2 K. After the design optimization one single cell cavity was fabricated from large grain (RRR>99) Niobium material. This report presents the design, fabrication, electron beam welding and RF measurements at room temperature before and after electron beam welding.