Investigation of the Effect of Strong Currents on Superconducting Properties and Surface Resistance of High Performance Materials for Accelerator Cavities

Temple University, Philadelphia PA

Investigators

Abstract

The primary aim of this project is to improve the performance of particle accelerators, opening new possibilities for high-energy experiments on the fundamental nature of matter. Currently, particle accelerators rely on superconducting radio frequency (SRF) resonator cavities to accelerate and control beams of charged particles in high energy collision experiments (such as at the Large Hadron Collider at CERN) or in x-ray lasers (such as at the Coherent Light Source at SLAC). Increasing the accelerating fields and reducing power consumption of SRF cavities is essential for the development of the next generation of accelerators. Two objectives will be pursued in this work. First is the understanding of fundamental physical and materials science mechanisms behind optimization of the state of the art superconducting cavities made with alloys of Niobium (Nb). The second effort is focused on new accelerating structures and superconducting materials which could significantly improve the performance of the superconducting cavities as compared to Nb. This work will suggest efficient ways of improving the performance of SRF accelerator cavities and will engage undergraduate and graduate students in this area of great interest to physics and future applications by providing them with training in key technological areas. The main goal of this project is to investigate the local quasiparticle density of states of SRF materials and to correlate it with different materials treatments (such as low-temperature baking and nitrogen infusion) and surface resistance measurements. The quasiparticle density of states is a key characteristic determining the power loss and the high-field performance of SRF cavities. The synergy of new experimental techniques (low temperature scanning tunneling microscopy and spectroscopy) and theory will allow the group to address the underlying physics and materials science mechanisms which are instrumental for achieving higher accelerating gradients and lower power losses in SRF cavities.