Error Emittance and Error Twiss Functions in the Problem of Reconstruction of Difference Orbit Parameters by Usage of BPMs with Finite Resolution

TL;DR

This paper introduces a dynamical perspective on how finite BPM resolution affects the accuracy of reconstructed difference orbit parameters in accelerators, using concepts like emittance and Twiss functions.

Contribution

It presents a novel dynamical approach to analyze errors in orbit reconstruction caused by BPM resolution limitations, linking measurement errors to accelerator physics concepts.

Findings

Error emittance quantifies measurement inaccuracies.

Error Twiss functions describe error propagation along the accelerator.

The approach provides new insights into BPM system performance.

Abstract

The problem of errors, arising due to finite BPM resolution, in the difference orbit parameters, which are found as a least squares fit to the BPM data, is one of the standard problems of the accelerator physics. In this article we present a "dynamical point of view" on this problem, which allows us to describe properties of the BPM measurement system in terms of the usual accelerator physics concepts of emittance and betatron functions.