A Study of Dynamic Lorentz Force Detuning of 650 MHz {\beta}g= 0.9 Superconducting Radiofrequency Cavity

TL;DR

This paper investigates dynamic Lorentz force detuning in 650 MHz superconducting cavities and proposes an optimized design with inter-cell stiffeners to mitigate detuning effects in high-gradient accelerators.

Contribution

It introduces a general sequential design methodology for analyzing and optimizing superconducting cavities against dynamic Lorentz force detuning, applicable to various geometries.

Findings

Optimized cavity design with inter-cell stiffeners reduces detuning.

Methodology effectively predicts dynamic detuning in 3D models.

Design improvements enhance cavity stability in pulsed operation.

Abstract

The small bandwidth of superconducting cavities makes the study of dynamic Lorentz force detuning and its compensation indispensable in case of pulsed mode operation of high gradient accelerators. In this paper, we present the study of this detuning and also propose an optimized design for five cell 650 MHz {\beta}g= 0.9 elliptic superconducting cavities, which will be used in the high energy section of the 1 GeV H- linear accelerator for the proposed Indian Spallation Neutron Source project, by suitably inserting the inter-cell stiffeners. The paper presents a sequential design methodology which starts with study of static Lorentz force detuning and tunability; and progresses to find out the structural modes and related dynamic detuning values by performing transient structural dynamics calculations. The developed methodology is general in nature and can be used for a three dimensional model of any geometry. The work will be useful for optimizing the design against dynamic Lorentz force detuning of superconducting radiofrequency cavities of any shape.