Model for hot spots and Q -slope behavior in granular niobium thin film superconducting rf cavities
Year: 2022
Type: article
Abstract: We propose a model to explain power dissipation leading to the formation of hot spots in the inner walls of niobium thin film superconducting rf cavities. The physical mechanism that we explore is due to the constriction of surface electrical current flow at grain interface boundaries. This constriction creates an additional electrical contact resistance which induces localized punctual heat dissipation. The temperature at these spots is derived; and the electrical contact resistance is shown to depend on the magnetic field, on the grain contact size over which dissipation occurs, and on other key parameters, including the effective London penetration depth and the frequency. The surface resistance and the quality factors are determined using our model and are shown to be in excellent agreement with experimental data.
Authors: Aymeric Ramiere, Claire Z. Antoine, Jay Amrit
Institutions: Shenzhen University, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, CEA Paris-Saclay, Département des Accélérateurs, de Cryogénie et de Magnétisme, Centre National de la Recherche Scientifique, Laboratoire Interdisciplinaire des Sciences du Numérique
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4212866792