A new approach to calculate the transport matrix in RF cavities

TL;DR

This paper introduces a realistic method for calculating the transport matrix in RF cavities by jointly solving longitudinal and transverse particle motion equations, validated against ASTRA simulations for TESLA-type cavities.

Contribution

It presents a novel approach based on joint equations of motion, improving accuracy over existing matrix methods for RF cavity modeling.

Findings

Complete agreement with ASTRA code for TESLA-type cavity tracking

The method is suitable for implementation into MARS15 code

Provides a more realistic calculation of particle transport in RF fields

Abstract

A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm will be implemented into the MARS15 code.